/* NOTE: This is generated code. Look in Misc/lapack_lite for information on remaking this file. */ #include "f2c.h" #ifdef HAVE_CONFIG #include "config.h" #else extern doublereal dlamch_(char *); #define EPSILON dlamch_("Epsilon") #define SAFEMINIMUM dlamch_("Safe minimum") #define PRECISION dlamch_("Precision") #define BASE dlamch_("Base") #endif extern doublereal dlapy2_(doublereal *x, doublereal *y); /* f2c knows the exact rules for precedence, and so omits parentheses where not strictly necessary. Since this is generated code, we don't really care if it's readable, and we know what is written is correct. So don't warn about them. */ #if defined(__GNUC__) #pragma GCC diagnostic ignored "-Wparentheses" #endif /* Table of constant values */ static integer c__1 = 1; static doublecomplex c_b56 = {0.,0.}; static doublecomplex c_b57 = {1.,0.}; static integer c_n1 = -1; static integer c__3 = 3; static integer c__2 = 2; static integer c__0 = 0; static integer c__65 = 65; static integer c__9 = 9; static integer c__6 = 6; static doublereal c_b328 = 0.; static doublereal c_b1034 = 1.; static integer c__12 = 12; static integer c__49 = 49; static doublereal c_b1276 = -1.; static integer c__13 = 13; static integer c__15 = 15; static integer c__14 = 14; static integer c__16 = 16; static logical c_false = FALSE_; static logical c_true = TRUE_; static doublereal c_b2435 = .5; /* Subroutine */ int zgebak_(char *job, char *side, integer *n, integer *ilo, integer *ihi, doublereal *scale, integer *m, doublecomplex *v, integer *ldv, integer *info) { /* System generated locals */ integer v_dim1, v_offset, i__1; /* Local variables */ static integer i__, k; static doublereal s; static integer ii; extern logical lsame_(char *, char *); static logical leftv; extern /* Subroutine */ int zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *), zdscal_(integer *, doublereal *, doublecomplex *, integer *); static logical rightv; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGEBAK forms the right or left eigenvectors of a complex general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by ZGEBAL. Arguments ========= JOB (input) CHARACTER*1 Specifies the type of backward transformation required: = 'N', do nothing, return immediately; = 'P', do backward transformation for permutation only; = 'S', do backward transformation for scaling only; = 'B', do backward transformations for both permutation and scaling. JOB must be the same as the argument JOB supplied to ZGEBAL. SIDE (input) CHARACTER*1 = 'R': V contains right eigenvectors; = 'L': V contains left eigenvectors. N (input) INTEGER The number of rows of the matrix V. N >= 0. ILO (input) INTEGER IHI (input) INTEGER The integers ILO and IHI determined by ZGEBAL. 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. SCALE (input) DOUBLE PRECISION array, dimension (N) Details of the permutation and scaling factors, as returned by ZGEBAL. M (input) INTEGER The number of columns of the matrix V. M >= 0. V (input/output) COMPLEX*16 array, dimension (LDV,M) On entry, the matrix of right or left eigenvectors to be transformed, as returned by ZHSEIN or ZTREVC. On exit, V is overwritten by the transformed eigenvectors. LDV (input) INTEGER The leading dimension of the array V. LDV >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. ===================================================================== Decode and Test the input parameters */ /* Parameter adjustments */ --scale; v_dim1 = *ldv; v_offset = 1 + v_dim1; v -= v_offset; /* Function Body */ rightv = lsame_(side, "R"); leftv = lsame_(side, "L"); *info = 0; if (! lsame_(job, "N") && ! lsame_(job, "P") && ! lsame_(job, "S") && ! lsame_(job, "B")) { *info = -1; } else if (! rightv && ! leftv) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*ilo < 1 || *ilo > max(1,*n)) { *info = -4; } else if (*ihi < min(*ilo,*n) || *ihi > *n) { *info = -5; } else if (*m < 0) { *info = -7; } else if (*ldv < max(1,*n)) { *info = -9; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEBAK", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } if (*m == 0) { return 0; } if (lsame_(job, "N")) { return 0; } if (*ilo == *ihi) { goto L30; } /* Backward balance */ if (lsame_(job, "S") || lsame_(job, "B")) { if (rightv) { i__1 = *ihi; for (i__ = *ilo; i__ <= i__1; ++i__) { s = scale[i__]; zdscal_(m, &s, &v[i__ + v_dim1], ldv); /* L10: */ } } if (leftv) { i__1 = *ihi; for (i__ = *ilo; i__ <= i__1; ++i__) { s = 1. / scale[i__]; zdscal_(m, &s, &v[i__ + v_dim1], ldv); /* L20: */ } } } /* Backward permutation For I = ILO-1 step -1 until 1, IHI+1 step 1 until N do -- */ L30: if (lsame_(job, "P") || lsame_(job, "B")) { if (rightv) { i__1 = *n; for (ii = 1; ii <= i__1; ++ii) { i__ = ii; if (i__ >= *ilo && i__ <= *ihi) { goto L40; } if (i__ < *ilo) { i__ = *ilo - ii; } k = (integer) scale[i__]; if (k == i__) { goto L40; } zswap_(m, &v[i__ + v_dim1], ldv, &v[k + v_dim1], ldv); L40: ; } } if (leftv) { i__1 = *n; for (ii = 1; ii <= i__1; ++ii) { i__ = ii; if (i__ >= *ilo && i__ <= *ihi) { goto L50; } if (i__ < *ilo) { i__ = *ilo - ii; } k = (integer) scale[i__]; if (k == i__) { goto L50; } zswap_(m, &v[i__ + v_dim1], ldv, &v[k + v_dim1], ldv); L50: ; } } } return 0; /* End of ZGEBAK */ } /* zgebak_ */ /* Subroutine */ int zgebal_(char *job, integer *n, doublecomplex *a, integer *lda, integer *ilo, integer *ihi, doublereal *scale, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublereal d__1, d__2; /* Builtin functions */ double d_imag(doublecomplex *), z_abs(doublecomplex *); /* Local variables */ static doublereal c__, f, g; static integer i__, j, k, l, m; static doublereal r__, s, ca, ra; static integer ica, ira, iexc; extern logical lsame_(char *, char *); extern /* Subroutine */ int zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *); static doublereal sfmin1, sfmin2, sfmax1, sfmax2; extern logical disnan_(doublereal *); extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_( integer *, doublereal *, doublecomplex *, integer *); extern integer izamax_(integer *, doublecomplex *, integer *); static logical noconv; /* -- LAPACK routine (version 3.2.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- June 2010 Purpose ======= ZGEBAL balances a general complex matrix A. This involves, first, permuting A by a similarity transformation to isolate eigenvalues in the first 1 to ILO-1 and last IHI+1 to N elements on the diagonal; and second, applying a diagonal similarity transformation to rows and columns ILO to IHI to make the rows and columns as close in norm as possible. Both steps are optional. Balancing may reduce the 1-norm of the matrix, and improve the accuracy of the computed eigenvalues and/or eigenvectors. Arguments ========= JOB (input) CHARACTER*1 Specifies the operations to be performed on A: = 'N': none: simply set ILO = 1, IHI = N, SCALE(I) = 1.0 for i = 1,...,N; = 'P': permute only; = 'S': scale only; = 'B': both permute and scale. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the input matrix A. On exit, A is overwritten by the balanced matrix. If JOB = 'N', A is not referenced. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). ILO (output) INTEGER IHI (output) INTEGER ILO and IHI are set to integers such that on exit A(i,j) = 0 if i > j and j = 1,...,ILO-1 or I = IHI+1,...,N. If JOB = 'N' or 'S', ILO = 1 and IHI = N. SCALE (output) DOUBLE PRECISION array, dimension (N) Details of the permutations and scaling factors applied to A. If P(j) is the index of the row and column interchanged with row and column j and D(j) is the scaling factor applied to row and column j, then SCALE(j) = P(j) for j = 1,...,ILO-1 = D(j) for j = ILO,...,IHI = P(j) for j = IHI+1,...,N. The order in which the interchanges are made is N to IHI+1, then 1 to ILO-1. INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== The permutations consist of row and column interchanges which put the matrix in the form ( T1 X Y ) P A P = ( 0 B Z ) ( 0 0 T2 ) where T1 and T2 are upper triangular matrices whose eigenvalues lie along the diagonal. The column indices ILO and IHI mark the starting and ending columns of the submatrix B. Balancing consists of applying a diagonal similarity transformation inv(D) * B * D to make the 1-norms of each row of B and its corresponding column nearly equal. The output matrix is ( T1 X*D Y ) ( 0 inv(D)*B*D inv(D)*Z ). ( 0 0 T2 ) Information about the permutations P and the diagonal matrix D is returned in the vector SCALE. This subroutine is based on the EISPACK routine CBAL. Modified by Tzu-Yi Chen, Computer Science Division, University of California at Berkeley, USA ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --scale; /* Function Body */ *info = 0; if (! lsame_(job, "N") && ! lsame_(job, "P") && ! lsame_(job, "S") && ! lsame_(job, "B")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEBAL", &i__1); return 0; } k = 1; l = *n; if (*n == 0) { goto L210; } if (lsame_(job, "N")) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { scale[i__] = 1.; /* L10: */ } goto L210; } if (lsame_(job, "S")) { goto L120; } /* Permutation to isolate eigenvalues if possible */ goto L50; /* Row and column exchange. */ L20: scale[m] = (doublereal) j; if (j == m) { goto L30; } zswap_(&l, &a[j * a_dim1 + 1], &c__1, &a[m * a_dim1 + 1], &c__1); i__1 = *n - k + 1; zswap_(&i__1, &a[j + k * a_dim1], lda, &a[m + k * a_dim1], lda); L30: switch (iexc) { case 1: goto L40; case 2: goto L80; } /* Search for rows isolating an eigenvalue and push them down. */ L40: if (l == 1) { goto L210; } --l; L50: for (j = l; j >= 1; --j) { i__1 = l; for (i__ = 1; i__ <= i__1; ++i__) { if (i__ == j) { goto L60; } i__2 = j + i__ * a_dim1; if (a[i__2].r != 0. || d_imag(&a[j + i__ * a_dim1]) != 0.) { goto L70; } L60: ; } m = l; iexc = 1; goto L20; L70: ; } goto L90; /* Search for columns isolating an eigenvalue and push them left. */ L80: ++k; L90: i__1 = l; for (j = k; j <= i__1; ++j) { i__2 = l; for (i__ = k; i__ <= i__2; ++i__) { if (i__ == j) { goto L100; } i__3 = i__ + j * a_dim1; if (a[i__3].r != 0. || d_imag(&a[i__ + j * a_dim1]) != 0.) { goto L110; } L100: ; } m = k; iexc = 2; goto L20; L110: ; } L120: i__1 = l; for (i__ = k; i__ <= i__1; ++i__) { scale[i__] = 1.; /* L130: */ } if (lsame_(job, "P")) { goto L210; } /* Balance the submatrix in rows K to L. Iterative loop for norm reduction */ sfmin1 = SAFEMINIMUM / PRECISION; sfmax1 = 1. / sfmin1; sfmin2 = sfmin1 * 2.; sfmax2 = 1. / sfmin2; L140: noconv = FALSE_; i__1 = l; for (i__ = k; i__ <= i__1; ++i__) { c__ = 0.; r__ = 0.; i__2 = l; for (j = k; j <= i__2; ++j) { if (j == i__) { goto L150; } i__3 = j + i__ * a_dim1; c__ += (d__1 = a[i__3].r, abs(d__1)) + (d__2 = d_imag(&a[j + i__ * a_dim1]), abs(d__2)); i__3 = i__ + j * a_dim1; r__ += (d__1 = a[i__3].r, abs(d__1)) + (d__2 = d_imag(&a[i__ + j * a_dim1]), abs(d__2)); L150: ; } ica = izamax_(&l, &a[i__ * a_dim1 + 1], &c__1); ca = z_abs(&a[ica + i__ * a_dim1]); i__2 = *n - k + 1; ira = izamax_(&i__2, &a[i__ + k * a_dim1], lda); ra = z_abs(&a[i__ + (ira + k - 1) * a_dim1]); /* Guard against zero C or R due to underflow. */ if (c__ == 0. || r__ == 0.) { goto L200; } g = r__ / 2.; f = 1.; s = c__ + r__; L160: /* Computing MAX */ d__1 = max(f,c__); /* Computing MIN */ d__2 = min(r__,g); if (c__ >= g || max(d__1,ca) >= sfmax2 || min(d__2,ra) <= sfmin2) { goto L170; } d__1 = c__ + f + ca + r__ + g + ra; if (disnan_(&d__1)) { /* Exit if NaN to avoid infinite loop */ *info = -3; i__2 = -(*info); xerbla_("ZGEBAL", &i__2); return 0; } f *= 2.; c__ *= 2.; ca *= 2.; r__ /= 2.; g /= 2.; ra /= 2.; goto L160; L170: g = c__ / 2.; L180: /* Computing MIN */ d__1 = min(f,c__), d__1 = min(d__1,g); if (g < r__ || max(r__,ra) >= sfmax2 || min(d__1,ca) <= sfmin2) { goto L190; } f /= 2.; c__ /= 2.; g /= 2.; ca /= 2.; r__ *= 2.; ra *= 2.; goto L180; /* Now balance. */ L190: if (c__ + r__ >= s * .95) { goto L200; } if (f < 1. && scale[i__] < 1.) { if (f * scale[i__] <= sfmin1) { goto L200; } } if (f > 1. && scale[i__] > 1.) { if (scale[i__] >= sfmax1 / f) { goto L200; } } g = 1. / f; scale[i__] *= f; noconv = TRUE_; i__2 = *n - k + 1; zdscal_(&i__2, &g, &a[i__ + k * a_dim1], lda); zdscal_(&l, &f, &a[i__ * a_dim1 + 1], &c__1); L200: ; } if (noconv) { goto L140; } L210: *ilo = k; *ihi = l; return 0; /* End of ZGEBAL */ } /* zgebal_ */ /* Subroutine */ int zgebd2_(integer *m, integer *n, doublecomplex *a, integer *lda, doublereal *d__, doublereal *e, doublecomplex *tauq, doublecomplex *taup, doublecomplex *work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__; static doublecomplex alpha; extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlacgv_(integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGEBD2 reduces a complex general m by n matrix A to upper or lower real bidiagonal form B by a unitary transformation: Q' * A * P = B. If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. Arguments ========= M (input) INTEGER The number of rows in the matrix A. M >= 0. N (input) INTEGER The number of columns in the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the m by n general matrix to be reduced. On exit, if m >= n, the diagonal and the first superdiagonal are overwritten with the upper bidiagonal matrix B; the elements below the diagonal, with the array TAUQ, represent the unitary matrix Q as a product of elementary reflectors, and the elements above the first superdiagonal, with the array TAUP, represent the unitary matrix P as a product of elementary reflectors; if m < n, the diagonal and the first subdiagonal are overwritten with the lower bidiagonal matrix B; the elements below the first subdiagonal, with the array TAUQ, represent the unitary matrix Q as a product of elementary reflectors, and the elements above the diagonal, with the array TAUP, represent the unitary matrix P as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). D (output) DOUBLE PRECISION array, dimension (min(M,N)) The diagonal elements of the bidiagonal matrix B: D(i) = A(i,i). E (output) DOUBLE PRECISION array, dimension (min(M,N)-1) The off-diagonal elements of the bidiagonal matrix B: if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1; if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1. TAUQ (output) COMPLEX*16 array dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the unitary matrix Q. See Further Details. TAUP (output) COMPLEX*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the unitary matrix P. See Further Details. WORK (workspace) COMPLEX*16 array, dimension (max(M,N)) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== The matrices Q and P are represented as products of elementary reflectors: If m >= n, Q = H(1) H(2) . . . H(n) and P = G(1) G(2) . . . G(n-1) Each H(i) and G(i) has the form: H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' where tauq and taup are complex scalars, and v and u are complex vectors; v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in A(i+1:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in A(i,i+2:n); tauq is stored in TAUQ(i) and taup in TAUP(i). If m < n, Q = H(1) H(2) . . . H(m-1) and P = G(1) G(2) . . . G(m) Each H(i) and G(i) has the form: H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' where tauq and taup are complex scalars, v and u are complex vectors; v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i); u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i). The contents of A on exit are illustrated by the following examples: m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n): ( d e u1 u1 u1 ) ( d u1 u1 u1 u1 u1 ) ( v1 d e u2 u2 ) ( e d u2 u2 u2 u2 ) ( v1 v2 d e u3 ) ( v1 e d u3 u3 u3 ) ( v1 v2 v3 d e ) ( v1 v2 e d u4 u4 ) ( v1 v2 v3 v4 d ) ( v1 v2 v3 e d u5 ) ( v1 v2 v3 v4 v5 ) where d and e denote diagonal and off-diagonal elements of B, vi denotes an element of the vector defining H(i), and ui an element of the vector defining G(i). ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --d__; --e; --tauq; --taup; --work; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } if (*info < 0) { i__1 = -(*info); xerbla_("ZGEBD2", &i__1); return 0; } if (*m >= *n) { /* Reduce to upper bidiagonal form */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { /* Generate elementary reflector H(i) to annihilate A(i+1:m,i) */ i__2 = i__ + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *m - i__ + 1; /* Computing MIN */ i__3 = i__ + 1; zlarfg_(&i__2, &alpha, &a[min(i__3,*m) + i__ * a_dim1], &c__1, & tauq[i__]); i__2 = i__; d__[i__2] = alpha.r; i__2 = i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Apply H(i)' to A(i:m,i+1:n) from the left */ if (i__ < *n) { i__2 = *m - i__ + 1; i__3 = *n - i__; d_cnjg(&z__1, &tauq[i__]); zlarf_("Left", &i__2, &i__3, &a[i__ + i__ * a_dim1], &c__1, & z__1, &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]); } i__2 = i__ + i__ * a_dim1; i__3 = i__; a[i__2].r = d__[i__3], a[i__2].i = 0.; if (i__ < *n) { /* Generate elementary reflector G(i) to annihilate A(i,i+2:n) */ i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); i__2 = i__ + (i__ + 1) * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[i__ + min(i__3,*n) * a_dim1], lda, & taup[i__]); i__2 = i__; e[i__2] = alpha.r; i__2 = i__ + (i__ + 1) * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Apply G(i) to A(i+1:m,i+1:n) from the right */ i__2 = *m - i__; i__3 = *n - i__; zlarf_("Right", &i__2, &i__3, &a[i__ + (i__ + 1) * a_dim1], lda, &taup[i__], &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &work[1]); i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); i__2 = i__ + (i__ + 1) * a_dim1; i__3 = i__; a[i__2].r = e[i__3], a[i__2].i = 0.; } else { i__2 = i__; taup[i__2].r = 0., taup[i__2].i = 0.; } /* L10: */ } } else { /* Reduce to lower bidiagonal form */ i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { /* Generate elementary reflector G(i) to annihilate A(i,i+1:n) */ i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); i__2 = i__ + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__ + 1; /* Computing MIN */ i__3 = i__ + 1; zlarfg_(&i__2, &alpha, &a[i__ + min(i__3,*n) * a_dim1], lda, & taup[i__]); i__2 = i__; d__[i__2] = alpha.r; i__2 = i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Apply G(i) to A(i+1:m,i:n) from the right */ if (i__ < *m) { i__2 = *m - i__; i__3 = *n - i__ + 1; zlarf_("Right", &i__2, &i__3, &a[i__ + i__ * a_dim1], lda, & taup[i__], &a[i__ + 1 + i__ * a_dim1], lda, &work[1]); } i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); i__2 = i__ + i__ * a_dim1; i__3 = i__; a[i__2].r = d__[i__3], a[i__2].i = 0.; if (i__ < *m) { /* Generate elementary reflector H(i) to annihilate A(i+2:m,i) */ i__2 = i__ + 1 + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *m - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[min(i__3,*m) + i__ * a_dim1], &c__1, &tauq[i__]); i__2 = i__; e[i__2] = alpha.r; i__2 = i__ + 1 + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Apply H(i)' to A(i+1:m,i+1:n) from the left */ i__2 = *m - i__; i__3 = *n - i__; d_cnjg(&z__1, &tauq[i__]); zlarf_("Left", &i__2, &i__3, &a[i__ + 1 + i__ * a_dim1], & c__1, &z__1, &a[i__ + 1 + (i__ + 1) * a_dim1], lda, & work[1]); i__2 = i__ + 1 + i__ * a_dim1; i__3 = i__; a[i__2].r = e[i__3], a[i__2].i = 0.; } else { i__2 = i__; tauq[i__2].r = 0., tauq[i__2].i = 0.; } /* L20: */ } } return 0; /* End of ZGEBD2 */ } /* zgebd2_ */ /* Subroutine */ int zgebrd_(integer *m, integer *n, doublecomplex *a, integer *lda, doublereal *d__, doublereal *e, doublecomplex *tauq, doublecomplex *taup, doublecomplex *work, integer *lwork, integer * info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1; doublecomplex z__1; /* Local variables */ static integer i__, j, nb, nx; static doublereal ws; static integer nbmin, iinfo, minmn; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zgebd2_(integer *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, doublecomplex *, doublecomplex *, doublecomplex *, integer *), xerbla_(char *, integer *), zlabrd_(integer *, integer *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, doublecomplex *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static integer ldwrkx, ldwrky, lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGEBRD reduces a general complex M-by-N matrix A to upper or lower bidiagonal form B by a unitary transformation: Q**H * A * P = B. If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. Arguments ========= M (input) INTEGER The number of rows in the matrix A. M >= 0. N (input) INTEGER The number of columns in the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N general matrix to be reduced. On exit, if m >= n, the diagonal and the first superdiagonal are overwritten with the upper bidiagonal matrix B; the elements below the diagonal, with the array TAUQ, represent the unitary matrix Q as a product of elementary reflectors, and the elements above the first superdiagonal, with the array TAUP, represent the unitary matrix P as a product of elementary reflectors; if m < n, the diagonal and the first subdiagonal are overwritten with the lower bidiagonal matrix B; the elements below the first subdiagonal, with the array TAUQ, represent the unitary matrix Q as a product of elementary reflectors, and the elements above the diagonal, with the array TAUP, represent the unitary matrix P as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). D (output) DOUBLE PRECISION array, dimension (min(M,N)) The diagonal elements of the bidiagonal matrix B: D(i) = A(i,i). E (output) DOUBLE PRECISION array, dimension (min(M,N)-1) The off-diagonal elements of the bidiagonal matrix B: if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1; if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1. TAUQ (output) COMPLEX*16 array dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the unitary matrix Q. See Further Details. TAUP (output) COMPLEX*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors which represent the unitary matrix P. See Further Details. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. LWORK >= max(1,M,N). For optimum performance LWORK >= (M+N)*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== The matrices Q and P are represented as products of elementary reflectors: If m >= n, Q = H(1) H(2) . . . H(n) and P = G(1) G(2) . . . G(n-1) Each H(i) and G(i) has the form: H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' where tauq and taup are complex scalars, and v and u are complex vectors; v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in A(i+1:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in A(i,i+2:n); tauq is stored in TAUQ(i) and taup in TAUP(i). If m < n, Q = H(1) H(2) . . . H(m-1) and P = G(1) G(2) . . . G(m) Each H(i) and G(i) has the form: H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' where tauq and taup are complex scalars, and v and u are complex vectors; v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i); u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i). The contents of A on exit are illustrated by the following examples: m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n): ( d e u1 u1 u1 ) ( d u1 u1 u1 u1 u1 ) ( v1 d e u2 u2 ) ( e d u2 u2 u2 u2 ) ( v1 v2 d e u3 ) ( v1 e d u3 u3 u3 ) ( v1 v2 v3 d e ) ( v1 v2 e d u4 u4 ) ( v1 v2 v3 v4 d ) ( v1 v2 v3 e d u5 ) ( v1 v2 v3 v4 v5 ) where d and e denote diagonal and off-diagonal elements of B, vi denotes an element of the vector defining H(i), and ui an element of the vector defining G(i). ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --d__; --e; --tauq; --taup; --work; /* Function Body */ *info = 0; /* Computing MAX */ i__1 = 1, i__2 = ilaenv_(&c__1, "ZGEBRD", " ", m, n, &c_n1, &c_n1, ( ftnlen)6, (ftnlen)1); nb = max(i__1,i__2); lwkopt = (*m + *n) * nb; d__1 = (doublereal) lwkopt; work[1].r = d__1, work[1].i = 0.; lquery = *lwork == -1; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } else /* if(complicated condition) */ { /* Computing MAX */ i__1 = max(1,*m); if (*lwork < max(i__1,*n) && ! lquery) { *info = -10; } } if (*info < 0) { i__1 = -(*info); xerbla_("ZGEBRD", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ minmn = min(*m,*n); if (minmn == 0) { work[1].r = 1., work[1].i = 0.; return 0; } ws = (doublereal) max(*m,*n); ldwrkx = *m; ldwrky = *n; if (nb > 1 && nb < minmn) { /* Set the crossover point NX. Computing MAX */ i__1 = nb, i__2 = ilaenv_(&c__3, "ZGEBRD", " ", m, n, &c_n1, &c_n1, ( ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); /* Determine when to switch from blocked to unblocked code. */ if (nx < minmn) { ws = (doublereal) ((*m + *n) * nb); if ((doublereal) (*lwork) < ws) { /* Not enough work space for the optimal NB, consider using a smaller block size. */ nbmin = ilaenv_(&c__2, "ZGEBRD", " ", m, n, &c_n1, &c_n1, ( ftnlen)6, (ftnlen)1); if (*lwork >= (*m + *n) * nbmin) { nb = *lwork / (*m + *n); } else { nb = 1; nx = minmn; } } } } else { nx = minmn; } i__1 = minmn - nx; i__2 = nb; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Reduce rows and columns i:i+ib-1 to bidiagonal form and return the matrices X and Y which are needed to update the unreduced part of the matrix */ i__3 = *m - i__ + 1; i__4 = *n - i__ + 1; zlabrd_(&i__3, &i__4, &nb, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[ i__], &tauq[i__], &taup[i__], &work[1], &ldwrkx, &work[ldwrkx * nb + 1], &ldwrky); /* Update the trailing submatrix A(i+ib:m,i+ib:n), using an update of the form A := A - V*Y' - X*U' */ i__3 = *m - i__ - nb + 1; i__4 = *n - i__ - nb + 1; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", &i__3, &i__4, &nb, & z__1, &a[i__ + nb + i__ * a_dim1], lda, &work[ldwrkx * nb + nb + 1], &ldwrky, &c_b57, &a[i__ + nb + (i__ + nb) * a_dim1], lda); i__3 = *m - i__ - nb + 1; i__4 = *n - i__ - nb + 1; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "No transpose", &i__3, &i__4, &nb, &z__1, & work[nb + 1], &ldwrkx, &a[i__ + (i__ + nb) * a_dim1], lda, & c_b57, &a[i__ + nb + (i__ + nb) * a_dim1], lda); /* Copy diagonal and off-diagonal elements of B back into A */ if (*m >= *n) { i__3 = i__ + nb - 1; for (j = i__; j <= i__3; ++j) { i__4 = j + j * a_dim1; i__5 = j; a[i__4].r = d__[i__5], a[i__4].i = 0.; i__4 = j + (j + 1) * a_dim1; i__5 = j; a[i__4].r = e[i__5], a[i__4].i = 0.; /* L10: */ } } else { i__3 = i__ + nb - 1; for (j = i__; j <= i__3; ++j) { i__4 = j + j * a_dim1; i__5 = j; a[i__4].r = d__[i__5], a[i__4].i = 0.; i__4 = j + 1 + j * a_dim1; i__5 = j; a[i__4].r = e[i__5], a[i__4].i = 0.; /* L20: */ } } /* L30: */ } /* Use unblocked code to reduce the remainder of the matrix */ i__2 = *m - i__ + 1; i__1 = *n - i__ + 1; zgebd2_(&i__2, &i__1, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[i__], & tauq[i__], &taup[i__], &work[1], &iinfo); work[1].r = ws, work[1].i = 0.; return 0; /* End of ZGEBRD */ } /* zgebrd_ */ /* Subroutine */ int zgeev_(char *jobvl, char *jobvr, integer *n, doublecomplex *a, integer *lda, doublecomplex *w, doublecomplex *vl, integer *ldvl, doublecomplex *vr, integer *ldvr, doublecomplex *work, integer *lwork, doublereal *rwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, vl_dim1, vl_offset, vr_dim1, vr_offset, i__1, i__2, i__3; doublereal d__1, d__2; doublecomplex z__1, z__2; /* Builtin functions */ double sqrt(doublereal), d_imag(doublecomplex *); void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, k, ihi; static doublereal scl; static integer ilo; static doublereal dum[1], eps; static doublecomplex tmp; static integer ibal; static char side[1]; static doublereal anrm; static integer ierr, itau, iwrk, nout; extern logical lsame_(char *, char *); extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *), dlabad_(doublereal *, doublereal *); extern doublereal dznrm2_(integer *, doublecomplex *, integer *); static logical scalea; static doublereal cscale; extern /* Subroutine */ int zgebak_(char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublecomplex *, integer *, integer *), zgebal_(char *, integer *, doublecomplex *, integer *, integer *, integer *, doublereal *, integer *); extern integer idamax_(integer *, doublereal *, integer *); extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static logical select[1]; extern /* Subroutine */ int zdscal_(integer *, doublereal *, doublecomplex *, integer *); static doublereal bignum; extern doublereal zlange_(char *, integer *, integer *, doublecomplex *, integer *, doublereal *); extern /* Subroutine */ int zgehrd_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *), zlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer minwrk, maxwrk; static logical wantvl; static doublereal smlnum; static integer hswork, irwork; extern /* Subroutine */ int zhseqr_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *), ztrevc_(char *, char *, logical *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, doublereal *, integer *); static logical lquery, wantvr; extern /* Subroutine */ int zunghr_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); /* -- LAPACK driver routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGEEV computes for an N-by-N complex nonsymmetric matrix A, the eigenvalues and, optionally, the left and/or right eigenvectors. The right eigenvector v(j) of A satisfies A * v(j) = lambda(j) * v(j) where lambda(j) is its eigenvalue. The left eigenvector u(j) of A satisfies u(j)**H * A = lambda(j) * u(j)**H where u(j)**H denotes the conjugate transpose of u(j). The computed eigenvectors are normalized to have Euclidean norm equal to 1 and largest component real. Arguments ========= JOBVL (input) CHARACTER*1 = 'N': left eigenvectors of A are not computed; = 'V': left eigenvectors of are computed. JOBVR (input) CHARACTER*1 = 'N': right eigenvectors of A are not computed; = 'V': right eigenvectors of A are computed. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the N-by-N matrix A. On exit, A has been overwritten. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). W (output) COMPLEX*16 array, dimension (N) W contains the computed eigenvalues. VL (output) COMPLEX*16 array, dimension (LDVL,N) If JOBVL = 'V', the left eigenvectors u(j) are stored one after another in the columns of VL, in the same order as their eigenvalues. If JOBVL = 'N', VL is not referenced. u(j) = VL(:,j), the j-th column of VL. LDVL (input) INTEGER The leading dimension of the array VL. LDVL >= 1; if JOBVL = 'V', LDVL >= N. VR (output) COMPLEX*16 array, dimension (LDVR,N) If JOBVR = 'V', the right eigenvectors v(j) are stored one after another in the columns of VR, in the same order as their eigenvalues. If JOBVR = 'N', VR is not referenced. v(j) = VR(:,j), the j-th column of VR. LDVR (input) INTEGER The leading dimension of the array VR. LDVR >= 1; if JOBVR = 'V', LDVR >= N. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= max(1,2*N). For good performance, LWORK must generally be larger. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. RWORK (workspace) DOUBLE PRECISION array, dimension (2*N) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. > 0: if INFO = i, the QR algorithm failed to compute all the eigenvalues, and no eigenvectors have been computed; elements and i+1:N of W contain eigenvalues which have converged. ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --w; vl_dim1 = *ldvl; vl_offset = 1 + vl_dim1; vl -= vl_offset; vr_dim1 = *ldvr; vr_offset = 1 + vr_dim1; vr -= vr_offset; --work; --rwork; /* Function Body */ *info = 0; lquery = *lwork == -1; wantvl = lsame_(jobvl, "V"); wantvr = lsame_(jobvr, "V"); if (! wantvl && ! lsame_(jobvl, "N")) { *info = -1; } else if (! wantvr && ! lsame_(jobvr, "N")) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } else if (*ldvl < 1 || wantvl && *ldvl < *n) { *info = -8; } else if (*ldvr < 1 || wantvr && *ldvr < *n) { *info = -10; } /* Compute workspace (Note: Comments in the code beginning "Workspace:" describe the minimal amount of workspace needed at that point in the code, as well as the preferred amount for good performance. CWorkspace refers to complex workspace, and RWorkspace to real workspace. NB refers to the optimal block size for the immediately following subroutine, as returned by ILAENV. HSWORK refers to the workspace preferred by ZHSEQR, as calculated below. HSWORK is computed assuming ILO=1 and IHI=N, the worst case.) */ if (*info == 0) { if (*n == 0) { minwrk = 1; maxwrk = 1; } else { maxwrk = *n + *n * ilaenv_(&c__1, "ZGEHRD", " ", n, &c__1, n, & c__0, (ftnlen)6, (ftnlen)1); minwrk = *n << 1; if (wantvl) { /* Computing MAX */ i__1 = maxwrk, i__2 = *n + (*n - 1) * ilaenv_(&c__1, "ZUNGHR", " ", n, &c__1, n, &c_n1, (ftnlen)6, (ftnlen)1); maxwrk = max(i__1,i__2); zhseqr_("S", "V", n, &c__1, n, &a[a_offset], lda, &w[1], &vl[ vl_offset], ldvl, &work[1], &c_n1, info); } else if (wantvr) { /* Computing MAX */ i__1 = maxwrk, i__2 = *n + (*n - 1) * ilaenv_(&c__1, "ZUNGHR", " ", n, &c__1, n, &c_n1, (ftnlen)6, (ftnlen)1); maxwrk = max(i__1,i__2); zhseqr_("S", "V", n, &c__1, n, &a[a_offset], lda, &w[1], &vr[ vr_offset], ldvr, &work[1], &c_n1, info); } else { zhseqr_("E", "N", n, &c__1, n, &a[a_offset], lda, &w[1], &vr[ vr_offset], ldvr, &work[1], &c_n1, info); } hswork = (integer) work[1].r; /* Computing MAX */ i__1 = max(maxwrk,hswork); maxwrk = max(i__1,minwrk); } work[1].r = (doublereal) maxwrk, work[1].i = 0.; if (*lwork < minwrk && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEEV ", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Get machine constants */ eps = PRECISION; smlnum = SAFEMINIMUM; bignum = 1. / smlnum; dlabad_(&smlnum, &bignum); smlnum = sqrt(smlnum) / eps; bignum = 1. / smlnum; /* Scale A if max element outside range [SMLNUM,BIGNUM] */ anrm = zlange_("M", n, n, &a[a_offset], lda, dum); scalea = FALSE_; if (anrm > 0. && anrm < smlnum) { scalea = TRUE_; cscale = smlnum; } else if (anrm > bignum) { scalea = TRUE_; cscale = bignum; } if (scalea) { zlascl_("G", &c__0, &c__0, &anrm, &cscale, n, n, &a[a_offset], lda, & ierr); } /* Balance the matrix (CWorkspace: none) (RWorkspace: need N) */ ibal = 1; zgebal_("B", n, &a[a_offset], lda, &ilo, &ihi, &rwork[ibal], &ierr); /* Reduce to upper Hessenberg form (CWorkspace: need 2*N, prefer N+N*NB) (RWorkspace: none) */ itau = 1; iwrk = itau + *n; i__1 = *lwork - iwrk + 1; zgehrd_(n, &ilo, &ihi, &a[a_offset], lda, &work[itau], &work[iwrk], &i__1, &ierr); if (wantvl) { /* Want left eigenvectors Copy Householder vectors to VL */ *(unsigned char *)side = 'L'; zlacpy_("L", n, n, &a[a_offset], lda, &vl[vl_offset], ldvl) ; /* Generate unitary matrix in VL (CWorkspace: need 2*N-1, prefer N+(N-1)*NB) (RWorkspace: none) */ i__1 = *lwork - iwrk + 1; zunghr_(n, &ilo, &ihi, &vl[vl_offset], ldvl, &work[itau], &work[iwrk], &i__1, &ierr); /* Perform QR iteration, accumulating Schur vectors in VL (CWorkspace: need 1, prefer HSWORK (see comments) ) (RWorkspace: none) */ iwrk = itau; i__1 = *lwork - iwrk + 1; zhseqr_("S", "V", n, &ilo, &ihi, &a[a_offset], lda, &w[1], &vl[ vl_offset], ldvl, &work[iwrk], &i__1, info); if (wantvr) { /* Want left and right eigenvectors Copy Schur vectors to VR */ *(unsigned char *)side = 'B'; zlacpy_("F", n, n, &vl[vl_offset], ldvl, &vr[vr_offset], ldvr); } } else if (wantvr) { /* Want right eigenvectors Copy Householder vectors to VR */ *(unsigned char *)side = 'R'; zlacpy_("L", n, n, &a[a_offset], lda, &vr[vr_offset], ldvr) ; /* Generate unitary matrix in VR (CWorkspace: need 2*N-1, prefer N+(N-1)*NB) (RWorkspace: none) */ i__1 = *lwork - iwrk + 1; zunghr_(n, &ilo, &ihi, &vr[vr_offset], ldvr, &work[itau], &work[iwrk], &i__1, &ierr); /* Perform QR iteration, accumulating Schur vectors in VR (CWorkspace: need 1, prefer HSWORK (see comments) ) (RWorkspace: none) */ iwrk = itau; i__1 = *lwork - iwrk + 1; zhseqr_("S", "V", n, &ilo, &ihi, &a[a_offset], lda, &w[1], &vr[ vr_offset], ldvr, &work[iwrk], &i__1, info); } else { /* Compute eigenvalues only (CWorkspace: need 1, prefer HSWORK (see comments) ) (RWorkspace: none) */ iwrk = itau; i__1 = *lwork - iwrk + 1; zhseqr_("E", "N", n, &ilo, &ihi, &a[a_offset], lda, &w[1], &vr[ vr_offset], ldvr, &work[iwrk], &i__1, info); } /* If INFO > 0 from ZHSEQR, then quit */ if (*info > 0) { goto L50; } if (wantvl || wantvr) { /* Compute left and/or right eigenvectors (CWorkspace: need 2*N) (RWorkspace: need 2*N) */ irwork = ibal + *n; ztrevc_(side, "B", select, n, &a[a_offset], lda, &vl[vl_offset], ldvl, &vr[vr_offset], ldvr, n, &nout, &work[iwrk], &rwork[irwork], &ierr); } if (wantvl) { /* Undo balancing of left eigenvectors (CWorkspace: none) (RWorkspace: need N) */ zgebak_("B", "L", n, &ilo, &ihi, &rwork[ibal], n, &vl[vl_offset], ldvl, &ierr); /* Normalize left eigenvectors and make largest component real */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { scl = 1. / dznrm2_(n, &vl[i__ * vl_dim1 + 1], &c__1); zdscal_(n, &scl, &vl[i__ * vl_dim1 + 1], &c__1); i__2 = *n; for (k = 1; k <= i__2; ++k) { i__3 = k + i__ * vl_dim1; /* Computing 2nd power */ d__1 = vl[i__3].r; /* Computing 2nd power */ d__2 = d_imag(&vl[k + i__ * vl_dim1]); rwork[irwork + k - 1] = d__1 * d__1 + d__2 * d__2; /* L10: */ } k = idamax_(n, &rwork[irwork], &c__1); d_cnjg(&z__2, &vl[k + i__ * vl_dim1]); d__1 = sqrt(rwork[irwork + k - 1]); z__1.r = z__2.r / d__1, z__1.i = z__2.i / d__1; tmp.r = z__1.r, tmp.i = z__1.i; zscal_(n, &tmp, &vl[i__ * vl_dim1 + 1], &c__1); i__2 = k + i__ * vl_dim1; i__3 = k + i__ * vl_dim1; d__1 = vl[i__3].r; z__1.r = d__1, z__1.i = 0.; vl[i__2].r = z__1.r, vl[i__2].i = z__1.i; /* L20: */ } } if (wantvr) { /* Undo balancing of right eigenvectors (CWorkspace: none) (RWorkspace: need N) */ zgebak_("B", "R", n, &ilo, &ihi, &rwork[ibal], n, &vr[vr_offset], ldvr, &ierr); /* Normalize right eigenvectors and make largest component real */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { scl = 1. / dznrm2_(n, &vr[i__ * vr_dim1 + 1], &c__1); zdscal_(n, &scl, &vr[i__ * vr_dim1 + 1], &c__1); i__2 = *n; for (k = 1; k <= i__2; ++k) { i__3 = k + i__ * vr_dim1; /* Computing 2nd power */ d__1 = vr[i__3].r; /* Computing 2nd power */ d__2 = d_imag(&vr[k + i__ * vr_dim1]); rwork[irwork + k - 1] = d__1 * d__1 + d__2 * d__2; /* L30: */ } k = idamax_(n, &rwork[irwork], &c__1); d_cnjg(&z__2, &vr[k + i__ * vr_dim1]); d__1 = sqrt(rwork[irwork + k - 1]); z__1.r = z__2.r / d__1, z__1.i = z__2.i / d__1; tmp.r = z__1.r, tmp.i = z__1.i; zscal_(n, &tmp, &vr[i__ * vr_dim1 + 1], &c__1); i__2 = k + i__ * vr_dim1; i__3 = k + i__ * vr_dim1; d__1 = vr[i__3].r; z__1.r = d__1, z__1.i = 0.; vr[i__2].r = z__1.r, vr[i__2].i = z__1.i; /* L40: */ } } /* Undo scaling if necessary */ L50: if (scalea) { i__1 = *n - *info; /* Computing MAX */ i__3 = *n - *info; i__2 = max(i__3,1); zlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &w[*info + 1] , &i__2, &ierr); if (*info > 0) { i__1 = ilo - 1; zlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &w[1], n, &ierr); } } work[1].r = (doublereal) maxwrk, work[1].i = 0.; return 0; /* End of ZGEEV */ } /* zgeev_ */ /* Subroutine */ int zgehd2_(integer *n, integer *ilo, integer *ihi, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__; static doublecomplex alpha; extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGEHD2 reduces a complex general matrix A to upper Hessenberg form H by a unitary similarity transformation: Q' * A * Q = H . Arguments ========= N (input) INTEGER The order of the matrix A. N >= 0. ILO (input) INTEGER IHI (input) INTEGER It is assumed that A is already upper triangular in rows and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally set by a previous call to ZGEBAL; otherwise they should be set to 1 and N respectively. See Further Details. 1 <= ILO <= IHI <= max(1,N). A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the n by n general matrix to be reduced. On exit, the upper triangle and the first subdiagonal of A are overwritten with the upper Hessenberg matrix H, and the elements below the first subdiagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). TAU (output) COMPLEX*16 array, dimension (N-1) The scalar factors of the elementary reflectors (see Further Details). WORK (workspace) COMPLEX*16 array, dimension (N) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== The matrix Q is represented as a product of (ihi-ilo) elementary reflectors Q = H(ilo) H(ilo+1) . . . H(ihi-1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i) = 0, v(i+1) = 1 and v(ihi+1:n) = 0; v(i+2:ihi) is stored on exit in A(i+2:ihi,i), and tau in TAU(i). The contents of A are illustrated by the following example, with n = 7, ilo = 2 and ihi = 6: on entry, on exit, ( a a a a a a a ) ( a a h h h h a ) ( a a a a a a ) ( a h h h h a ) ( a a a a a a ) ( h h h h h h ) ( a a a a a a ) ( v2 h h h h h ) ( a a a a a a ) ( v2 v3 h h h h ) ( a a a a a a ) ( v2 v3 v4 h h h ) ( a ) ( a ) where a denotes an element of the original matrix A, h denotes a modified element of the upper Hessenberg matrix H, and vi denotes an element of the vector defining H(i). ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; if (*n < 0) { *info = -1; } else if (*ilo < 1 || *ilo > max(1,*n)) { *info = -2; } else if (*ihi < min(*ilo,*n) || *ihi > *n) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEHD2", &i__1); return 0; } i__1 = *ihi - 1; for (i__ = *ilo; i__ <= i__1; ++i__) { /* Compute elementary reflector H(i) to annihilate A(i+2:ihi,i) */ i__2 = i__ + 1 + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *ihi - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[min(i__3,*n) + i__ * a_dim1], &c__1, &tau[ i__]); i__2 = i__ + 1 + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Apply H(i) to A(1:ihi,i+1:ihi) from the right */ i__2 = *ihi - i__; zlarf_("Right", ihi, &i__2, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[ i__], &a[(i__ + 1) * a_dim1 + 1], lda, &work[1]); /* Apply H(i)' to A(i+1:ihi,i+1:n) from the left */ i__2 = *ihi - i__; i__3 = *n - i__; d_cnjg(&z__1, &tau[i__]); zlarf_("Left", &i__2, &i__3, &a[i__ + 1 + i__ * a_dim1], &c__1, &z__1, &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &work[1]); i__2 = i__ + 1 + i__ * a_dim1; a[i__2].r = alpha.r, a[i__2].i = alpha.i; /* L10: */ } return 0; /* End of ZGEHD2 */ } /* zgehd2_ */ /* Subroutine */ int zgehrd_(integer *n, integer *ilo, integer *ihi, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; doublecomplex z__1; /* Local variables */ static integer i__, j; static doublecomplex t[4160] /* was [65][64] */; static integer ib; static doublecomplex ei; static integer nb, nh, nx, iws, nbmin, iinfo; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), ztrmm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer * , doublecomplex *, integer *), zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), zgehd2_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zlahr2_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_( char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer ldwork, lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2.1) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -- April 2009 -- Purpose ======= ZGEHRD reduces a complex general matrix A to upper Hessenberg form H by an unitary similarity transformation: Q' * A * Q = H . Arguments ========= N (input) INTEGER The order of the matrix A. N >= 0. ILO (input) INTEGER IHI (input) INTEGER It is assumed that A is already upper triangular in rows and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally set by a previous call to ZGEBAL; otherwise they should be set to 1 and N respectively. See Further Details. 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the N-by-N general matrix to be reduced. On exit, the upper triangle and the first subdiagonal of A are overwritten with the upper Hessenberg matrix H, and the elements below the first subdiagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). TAU (output) COMPLEX*16 array, dimension (N-1) The scalar factors of the elementary reflectors (see Further Details). Elements 1:ILO-1 and IHI:N-1 of TAU are set to zero. WORK (workspace/output) COMPLEX*16 array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= N*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== The matrix Q is represented as a product of (ihi-ilo) elementary reflectors Q = H(ilo) H(ilo+1) . . . H(ihi-1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i) = 0, v(i+1) = 1 and v(ihi+1:n) = 0; v(i+2:ihi) is stored on exit in A(i+2:ihi,i), and tau in TAU(i). The contents of A are illustrated by the following example, with n = 7, ilo = 2 and ihi = 6: on entry, on exit, ( a a a a a a a ) ( a a h h h h a ) ( a a a a a a ) ( a h h h h a ) ( a a a a a a ) ( h h h h h h ) ( a a a a a a ) ( v2 h h h h h ) ( a a a a a a ) ( v2 v3 h h h h ) ( a a a a a a ) ( v2 v3 v4 h h h ) ( a ) ( a ) where a denotes an element of the original matrix A, h denotes a modified element of the upper Hessenberg matrix H, and vi denotes an element of the vector defining H(i). This file is a slight modification of LAPACK-3.0's DGEHRD subroutine incorporating improvements proposed by Quintana-Orti and Van de Geijn (2006). (See DLAHR2.) ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; /* Computing MIN */ i__1 = 64, i__2 = ilaenv_(&c__1, "ZGEHRD", " ", n, ilo, ihi, &c_n1, ( ftnlen)6, (ftnlen)1); nb = min(i__1,i__2); lwkopt = *n * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; lquery = *lwork == -1; if (*n < 0) { *info = -1; } else if (*ilo < 1 || *ilo > max(1,*n)) { *info = -2; } else if (*ihi < min(*ilo,*n) || *ihi > *n) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } else if (*lwork < max(1,*n) && ! lquery) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEHRD", &i__1); return 0; } else if (lquery) { return 0; } /* Set elements 1:ILO-1 and IHI:N-1 of TAU to zero */ i__1 = *ilo - 1; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__; tau[i__2].r = 0., tau[i__2].i = 0.; /* L10: */ } i__1 = *n - 1; for (i__ = max(1,*ihi); i__ <= i__1; ++i__) { i__2 = i__; tau[i__2].r = 0., tau[i__2].i = 0.; /* L20: */ } /* Quick return if possible */ nh = *ihi - *ilo + 1; if (nh <= 1) { work[1].r = 1., work[1].i = 0.; return 0; } /* Determine the block size Computing MIN */ i__1 = 64, i__2 = ilaenv_(&c__1, "ZGEHRD", " ", n, ilo, ihi, &c_n1, ( ftnlen)6, (ftnlen)1); nb = min(i__1,i__2); nbmin = 2; iws = 1; if (nb > 1 && nb < nh) { /* Determine when to cross over from blocked to unblocked code (last block is always handled by unblocked code) Computing MAX */ i__1 = nb, i__2 = ilaenv_(&c__3, "ZGEHRD", " ", n, ilo, ihi, &c_n1, ( ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); if (nx < nh) { /* Determine if workspace is large enough for blocked code */ iws = *n * nb; if (*lwork < iws) { /* Not enough workspace to use optimal NB: determine the minimum value of NB, and reduce NB or force use of unblocked code Computing MAX */ i__1 = 2, i__2 = ilaenv_(&c__2, "ZGEHRD", " ", n, ilo, ihi, & c_n1, (ftnlen)6, (ftnlen)1); nbmin = max(i__1,i__2); if (*lwork >= *n * nbmin) { nb = *lwork / *n; } else { nb = 1; } } } } ldwork = *n; if (nb < nbmin || nb >= nh) { /* Use unblocked code below */ i__ = *ilo; } else { /* Use blocked code */ i__1 = *ihi - 1 - nx; i__2 = nb; for (i__ = *ilo; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = nb, i__4 = *ihi - i__; ib = min(i__3,i__4); /* Reduce columns i:i+ib-1 to Hessenberg form, returning the matrices V and T of the block reflector H = I - V*T*V' which performs the reduction, and also the matrix Y = A*V*T */ zlahr2_(ihi, &i__, &ib, &a[i__ * a_dim1 + 1], lda, &tau[i__], t, & c__65, &work[1], &ldwork); /* Apply the block reflector H to A(1:ihi,i+ib:ihi) from the right, computing A := A - Y * V'. V(i+ib,ib-1) must be set to 1 */ i__3 = i__ + ib + (i__ + ib - 1) * a_dim1; ei.r = a[i__3].r, ei.i = a[i__3].i; i__3 = i__ + ib + (i__ + ib - 1) * a_dim1; a[i__3].r = 1., a[i__3].i = 0.; i__3 = *ihi - i__ - ib + 1; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", ihi, &i__3, &ib, & z__1, &work[1], &ldwork, &a[i__ + ib + i__ * a_dim1], lda, &c_b57, &a[(i__ + ib) * a_dim1 + 1], lda); i__3 = i__ + ib + (i__ + ib - 1) * a_dim1; a[i__3].r = ei.r, a[i__3].i = ei.i; /* Apply the block reflector H to A(1:i,i+1:i+ib-1) from the right */ i__3 = ib - 1; ztrmm_("Right", "Lower", "Conjugate transpose", "Unit", &i__, & i__3, &c_b57, &a[i__ + 1 + i__ * a_dim1], lda, &work[1], & ldwork); i__3 = ib - 2; for (j = 0; j <= i__3; ++j) { z__1.r = -1., z__1.i = -0.; zaxpy_(&i__, &z__1, &work[ldwork * j + 1], &c__1, &a[(i__ + j + 1) * a_dim1 + 1], &c__1); /* L30: */ } /* Apply the block reflector H to A(i+1:ihi,i+ib:n) from the left */ i__3 = *ihi - i__; i__4 = *n - i__ - ib + 1; zlarfb_("Left", "Conjugate transpose", "Forward", "Columnwise", & i__3, &i__4, &ib, &a[i__ + 1 + i__ * a_dim1], lda, t, & c__65, &a[i__ + 1 + (i__ + ib) * a_dim1], lda, &work[1], & ldwork); /* L40: */ } } /* Use unblocked code to reduce the rest of the matrix */ zgehd2_(n, &i__, ihi, &a[a_offset], lda, &tau[1], &work[1], &iinfo); work[1].r = (doublereal) iws, work[1].i = 0.; return 0; /* End of ZGEHRD */ } /* zgehrd_ */ /* Subroutine */ int zgelq2_(integer *m, integer *n, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; /* Local variables */ static integer i__, k; static doublecomplex alpha; extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlacgv_(integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- June 2010 Purpose ======= ZGELQ2 computes an LQ factorization of a complex m by n matrix A: A = L * Q. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the m by n matrix A. On exit, the elements on and below the diagonal of the array contain the m by min(m,n) lower trapezoidal matrix L (L is lower triangular if m <= n); the elements above the diagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors (see Further Details). LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). TAU (output) COMPLEX*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). WORK (workspace) COMPLEX*16 array, dimension (M) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== The matrix Q is represented as a product of elementary reflectors Q = H(k)' . . . H(2)' H(1)', where k = min(m,n). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; conjg(v(i+1:n)) is stored on exit in A(i,i+1:n), and tau in TAU(i). ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGELQ2", &i__1); return 0; } k = min(*m,*n); i__1 = k; for (i__ = 1; i__ <= i__1; ++i__) { /* Generate elementary reflector H(i) to annihilate A(i,i+1:n) */ i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); i__2 = i__ + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__ + 1; /* Computing MIN */ i__3 = i__ + 1; zlarfg_(&i__2, &alpha, &a[i__ + min(i__3,*n) * a_dim1], lda, &tau[i__] ); if (i__ < *m) { /* Apply H(i) to A(i+1:m,i:n) from the right */ i__2 = i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; i__2 = *m - i__; i__3 = *n - i__ + 1; zlarf_("Right", &i__2, &i__3, &a[i__ + i__ * a_dim1], lda, &tau[ i__], &a[i__ + 1 + i__ * a_dim1], lda, &work[1]); } i__2 = i__ + i__ * a_dim1; a[i__2].r = alpha.r, a[i__2].i = alpha.i; i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); /* L10: */ } return 0; /* End of ZGELQ2 */ } /* zgelq2_ */ /* Subroutine */ int zgelqf_(integer *m, integer *n, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, k, ib, nb, nx, iws, nbmin, iinfo; extern /* Subroutine */ int zgelq2_(integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), xerbla_( char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGELQF computes an LQ factorization of a complex M-by-N matrix A: A = L * Q. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, the elements on and below the diagonal of the array contain the m-by-min(m,n) lower trapezoidal matrix L (L is lower triangular if m <= n); the elements above the diagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors (see Further Details). LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). TAU (output) COMPLEX*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== The matrix Q is represented as a product of elementary reflectors Q = H(k)' . . . H(2)' H(1)', where k = min(m,n). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; conjg(v(i+1:n)) is stored on exit in A(i,i+1:n), and tau in TAU(i). ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; nb = ilaenv_(&c__1, "ZGELQF", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen) 1); lwkopt = *m * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; lquery = *lwork == -1; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } else if (*lwork < max(1,*m) && ! lquery) { *info = -7; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGELQF", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ k = min(*m,*n); if (k == 0) { work[1].r = 1., work[1].i = 0.; return 0; } nbmin = 2; nx = 0; iws = *m; if (nb > 1 && nb < k) { /* Determine when to cross over from blocked to unblocked code. Computing MAX */ i__1 = 0, i__2 = ilaenv_(&c__3, "ZGELQF", " ", m, n, &c_n1, &c_n1, ( ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); if (nx < k) { /* Determine if workspace is large enough for blocked code. */ ldwork = *m; iws = ldwork * nb; if (*lwork < iws) { /* Not enough workspace to use optimal NB: reduce NB and determine the minimum value of NB. */ nb = *lwork / ldwork; /* Computing MAX */ i__1 = 2, i__2 = ilaenv_(&c__2, "ZGELQF", " ", m, n, &c_n1, & c_n1, (ftnlen)6, (ftnlen)1); nbmin = max(i__1,i__2); } } } if (nb >= nbmin && nb < k && nx < k) { /* Use blocked code initially */ i__1 = k - nx; i__2 = nb; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = k - i__ + 1; ib = min(i__3,nb); /* Compute the LQ factorization of the current block A(i:i+ib-1,i:n) */ i__3 = *n - i__ + 1; zgelq2_(&ib, &i__3, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[ 1], &iinfo); if (i__ + ib <= *m) { /* Form the triangular factor of the block reflector H = H(i) H(i+1) . . . H(i+ib-1) */ i__3 = *n - i__ + 1; zlarft_("Forward", "Rowwise", &i__3, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[1], &ldwork); /* Apply H to A(i+ib:m,i:n) from the right */ i__3 = *m - i__ - ib + 1; i__4 = *n - i__ + 1; zlarfb_("Right", "No transpose", "Forward", "Rowwise", &i__3, &i__4, &ib, &a[i__ + i__ * a_dim1], lda, &work[1], & ldwork, &a[i__ + ib + i__ * a_dim1], lda, &work[ib + 1], &ldwork); } /* L10: */ } } else { i__ = 1; } /* Use unblocked code to factor the last or only block. */ if (i__ <= k) { i__2 = *m - i__ + 1; i__1 = *n - i__ + 1; zgelq2_(&i__2, &i__1, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[1] , &iinfo); } work[1].r = (doublereal) iws, work[1].i = 0.; return 0; /* End of ZGELQF */ } /* zgelqf_ */ /* Subroutine */ int zgelsd_(integer *m, integer *n, integer *nrhs, doublecomplex *a, integer *lda, doublecomplex *b, integer *ldb, doublereal *s, doublereal *rcond, integer *rank, doublecomplex *work, integer *lwork, doublereal *rwork, integer *iwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2, i__3, i__4; /* Builtin functions */ double log(doublereal); /* Local variables */ static integer ie, il, mm; static doublereal eps, anrm, bnrm; static integer itau, nlvl, iascl, ibscl; static doublereal sfmin; static integer minmn, maxmn, itaup, itauq, mnthr, nwork; extern /* Subroutine */ int dlabad_(doublereal *, doublereal *); extern /* Subroutine */ int dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *), dlaset_(char *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *), xerbla_(char *, integer *), zgebrd_(integer *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, doublecomplex *, doublecomplex *, doublecomplex *, integer *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern doublereal zlange_(char *, integer *, integer *, doublecomplex *, integer *, doublereal *); static doublereal bignum; extern /* Subroutine */ int zgelqf_(integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer * ), zlalsd_(char *, integer *, integer *, integer *, doublereal *, doublereal *, doublecomplex *, integer *, doublereal *, integer *, doublecomplex *, doublereal *, integer *, integer *), zlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublecomplex *, integer *, integer *), zgeqrf_(integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); static integer ldwork; extern /* Subroutine */ int zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static integer liwork, minwrk, maxwrk; static doublereal smlnum; extern /* Subroutine */ int zunmbr_(char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer * ); static integer lrwork; static logical lquery; static integer nrwork, smlsiz; extern /* Subroutine */ int zunmlq_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *), zunmqr_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK driver routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGELSD computes the minimum-norm solution to a real linear least squares problem: minimize 2-norm(| b - A*x |) using the singular value decomposition (SVD) of A. A is an M-by-N matrix which may be rank-deficient. Several right hand side vectors b and solution vectors x can be handled in a single call; they are stored as the columns of the M-by-NRHS right hand side matrix B and the N-by-NRHS solution matrix X. The problem is solved in three steps: (1) Reduce the coefficient matrix A to bidiagonal form with Householder tranformations, reducing the original problem into a "bidiagonal least squares problem" (BLS) (2) Solve the BLS using a divide and conquer approach. (3) Apply back all the Householder tranformations to solve the original least squares problem. The effective rank of A is determined by treating as zero those singular values which are less than RCOND times the largest singular value. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. NRHS (input) INTEGER The number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, A has been destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) On entry, the M-by-NRHS right hand side matrix B. On exit, B is overwritten by the N-by-NRHS solution matrix X. If m >= n and RANK = n, the residual sum-of-squares for the solution in the i-th column is given by the sum of squares of the modulus of elements n+1:m in that column. LDB (input) INTEGER The leading dimension of the array B. LDB >= max(1,M,N). S (output) DOUBLE PRECISION array, dimension (min(M,N)) The singular values of A in decreasing order. The condition number of A in the 2-norm = S(1)/S(min(m,n)). RCOND (input) DOUBLE PRECISION RCOND is used to determine the effective rank of A. Singular values S(i) <= RCOND*S(1) are treated as zero. If RCOND < 0, machine precision is used instead. RANK (output) INTEGER The effective rank of A, i.e., the number of singular values which are greater than RCOND*S(1). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK must be at least 1. The exact minimum amount of workspace needed depends on M, N and NRHS. As long as LWORK is at least 2*N + N*NRHS if M is greater than or equal to N or 2*M + M*NRHS if M is less than N, the code will execute correctly. For good performance, LWORK should generally be larger. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the array WORK and the minimum sizes of the arrays RWORK and IWORK, and returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK is issued by XERBLA. RWORK (workspace) DOUBLE PRECISION array, dimension (MAX(1,LRWORK)) LRWORK >= 10*N + 2*N*SMLSIZ + 8*N*NLVL + 3*SMLSIZ*NRHS + MAX( (SMLSIZ+1)**2, N*(1+NRHS) + 2*NRHS ) if M is greater than or equal to N or 10*M + 2*M*SMLSIZ + 8*M*NLVL + 3*SMLSIZ*NRHS + MAX( (SMLSIZ+1)**2, N*(1+NRHS) + 2*NRHS ) if M is less than N, the code will execute correctly. SMLSIZ is returned by ILAENV and is equal to the maximum size of the subproblems at the bottom of the computation tree (usually about 25), and NLVL = MAX( 0, INT( LOG_2( MIN( M,N )/(SMLSIZ+1) ) ) + 1 ) On exit, if INFO = 0, RWORK(1) returns the minimum LRWORK. IWORK (workspace) INTEGER array, dimension (MAX(1,LIWORK)) LIWORK >= max(1, 3*MINMN*NLVL + 11*MINMN), where MINMN = MIN( M,N ). On exit, if INFO = 0, IWORK(1) returns the minimum LIWORK. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. > 0: the algorithm for computing the SVD failed to converge; if INFO = i, i off-diagonal elements of an intermediate bidiagonal form did not converge to zero. Further Details =============== Based on contributions by Ming Gu and Ren-Cang Li, Computer Science Division, University of California at Berkeley, USA Osni Marques, LBNL/NERSC, USA ===================================================================== Test the input arguments. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; --s; --work; --rwork; --iwork; /* Function Body */ *info = 0; minmn = min(*m,*n); maxmn = max(*m,*n); lquery = *lwork == -1; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*nrhs < 0) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } else if (*ldb < max(1,maxmn)) { *info = -7; } /* Compute workspace. (Note: Comments in the code beginning "Workspace:" describe the minimal amount of workspace needed at that point in the code, as well as the preferred amount for good performance. NB refers to the optimal block size for the immediately following subroutine, as returned by ILAENV.) */ if (*info == 0) { minwrk = 1; maxwrk = 1; liwork = 1; lrwork = 1; if (minmn > 0) { smlsiz = ilaenv_(&c__9, "ZGELSD", " ", &c__0, &c__0, &c__0, &c__0, (ftnlen)6, (ftnlen)1); mnthr = ilaenv_(&c__6, "ZGELSD", " ", m, n, nrhs, &c_n1, (ftnlen) 6, (ftnlen)1); /* Computing MAX */ i__1 = (integer) (log((doublereal) minmn / (doublereal) (smlsiz + 1)) / log(2.)) + 1; nlvl = max(i__1,0); liwork = minmn * 3 * nlvl + minmn * 11; mm = *m; if (*m >= *n && *m >= mnthr) { /* Path 1a - overdetermined, with many more rows than columns. */ mm = *n; /* Computing MAX */ i__1 = maxwrk, i__2 = *n * ilaenv_(&c__1, "ZGEQRF", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = *nrhs * ilaenv_(&c__1, "ZUNMQR", "LC", m, nrhs, n, &c_n1, (ftnlen)6, (ftnlen)2); maxwrk = max(i__1,i__2); } if (*m >= *n) { /* Path 1 - overdetermined or exactly determined. Computing MAX Computing 2nd power */ i__3 = smlsiz + 1; i__1 = i__3 * i__3, i__2 = *n * (*nrhs + 1) + (*nrhs << 1); lrwork = *n * 10 + (*n << 1) * smlsiz + (*n << 3) * nlvl + smlsiz * 3 * *nrhs + max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + (mm + *n) * ilaenv_(&c__1, "ZGEBRD", " ", &mm, n, &c_n1, &c_n1, (ftnlen)6, ( ftnlen)1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *nrhs * ilaenv_(&c__1, "ZUNMBR", "QLC", &mm, nrhs, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + (*n - 1) * ilaenv_(&c__1, "ZUNMBR", "PLN", n, nrhs, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * *nrhs; maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = (*n << 1) + mm, i__2 = (*n << 1) + *n * *nrhs; minwrk = max(i__1,i__2); } if (*n > *m) { /* Computing MAX Computing 2nd power */ i__3 = smlsiz + 1; i__1 = i__3 * i__3, i__2 = *n * (*nrhs + 1) + (*nrhs << 1); lrwork = *m * 10 + (*m << 1) * smlsiz + (*m << 3) * nlvl + smlsiz * 3 * *nrhs + max(i__1,i__2); if (*n >= mnthr) { /* Path 2a - underdetermined, with many more columns than rows. */ maxwrk = *m + *m * ilaenv_(&c__1, "ZGELQF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = maxwrk, i__2 = *m * *m + (*m << 2) + (*m << 1) * ilaenv_(&c__1, "ZGEBRD", " ", m, m, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = *m * *m + (*m << 2) + *nrhs * ilaenv_(&c__1, "ZUNMBR", "QLC", m, nrhs, m, &c_n1, (ftnlen)6, (ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = *m * *m + (*m << 2) + (*m - 1) * ilaenv_(&c__1, "ZUNMLQ", "LC", n, nrhs, m, &c_n1, (ftnlen)6, (ftnlen)2); maxwrk = max(i__1,i__2); if (*nrhs > 1) { /* Computing MAX */ i__1 = maxwrk, i__2 = *m * *m + *m + *m * *nrhs; maxwrk = max(i__1,i__2); } else { /* Computing MAX */ i__1 = maxwrk, i__2 = *m * *m + (*m << 1); maxwrk = max(i__1,i__2); } /* Computing MAX */ i__1 = maxwrk, i__2 = *m * *m + (*m << 2) + *m * *nrhs; maxwrk = max(i__1,i__2); /* XXX: Ensure the Path 2a case below is triggered. The workspace calculation should use queries for all routines eventually. Computing MAX Computing MAX */ i__3 = *m, i__4 = (*m << 1) - 4, i__3 = max(i__3,i__4), i__3 = max(i__3,*nrhs), i__4 = *n - *m * 3; i__1 = maxwrk, i__2 = (*m << 2) + *m * *m + max(i__3,i__4) ; maxwrk = max(i__1,i__2); } else { /* Path 2 - underdetermined. */ maxwrk = (*m << 1) + (*n + *m) * ilaenv_(&c__1, "ZGEBRD", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *nrhs * ilaenv_(&c__1, "ZUNMBR", "QLC", m, nrhs, m, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "PLN", n, nrhs, m, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * *nrhs; maxwrk = max(i__1,i__2); } /* Computing MAX */ i__1 = (*m << 1) + *n, i__2 = (*m << 1) + *m * *nrhs; minwrk = max(i__1,i__2); } } minwrk = min(minwrk,maxwrk); work[1].r = (doublereal) maxwrk, work[1].i = 0.; iwork[1] = liwork; rwork[1] = (doublereal) lrwork; if (*lwork < minwrk && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("ZGELSD", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible. */ if (*m == 0 || *n == 0) { *rank = 0; return 0; } /* Get machine parameters. */ eps = PRECISION; sfmin = SAFEMINIMUM; smlnum = sfmin / eps; bignum = 1. / smlnum; dlabad_(&smlnum, &bignum); /* Scale A if max entry outside range [SMLNUM,BIGNUM]. */ anrm = zlange_("M", m, n, &a[a_offset], lda, &rwork[1]); iascl = 0; if (anrm > 0. && anrm < smlnum) { /* Scale matrix norm up to SMLNUM */ zlascl_("G", &c__0, &c__0, &anrm, &smlnum, m, n, &a[a_offset], lda, info); iascl = 1; } else if (anrm > bignum) { /* Scale matrix norm down to BIGNUM. */ zlascl_("G", &c__0, &c__0, &anrm, &bignum, m, n, &a[a_offset], lda, info); iascl = 2; } else if (anrm == 0.) { /* Matrix all zero. Return zero solution. */ i__1 = max(*m,*n); zlaset_("F", &i__1, nrhs, &c_b56, &c_b56, &b[b_offset], ldb); dlaset_("F", &minmn, &c__1, &c_b328, &c_b328, &s[1], &c__1) ; *rank = 0; goto L10; } /* Scale B if max entry outside range [SMLNUM,BIGNUM]. */ bnrm = zlange_("M", m, nrhs, &b[b_offset], ldb, &rwork[1]); ibscl = 0; if (bnrm > 0. && bnrm < smlnum) { /* Scale matrix norm up to SMLNUM. */ zlascl_("G", &c__0, &c__0, &bnrm, &smlnum, m, nrhs, &b[b_offset], ldb, info); ibscl = 1; } else if (bnrm > bignum) { /* Scale matrix norm down to BIGNUM. */ zlascl_("G", &c__0, &c__0, &bnrm, &bignum, m, nrhs, &b[b_offset], ldb, info); ibscl = 2; } /* If M < N make sure B(M+1:N,:) = 0 */ if (*m < *n) { i__1 = *n - *m; zlaset_("F", &i__1, nrhs, &c_b56, &c_b56, &b[*m + 1 + b_dim1], ldb); } /* Overdetermined case. */ if (*m >= *n) { /* Path 1 - overdetermined or exactly determined. */ mm = *m; if (*m >= mnthr) { /* Path 1a - overdetermined, with many more rows than columns */ mm = *n; itau = 1; nwork = itau + *n; /* Compute A=Q*R. (RWorkspace: need N) (CWorkspace: need N, prefer N*NB) */ i__1 = *lwork - nwork + 1; zgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], &i__1, info); /* Multiply B by transpose(Q). (RWorkspace: need N) (CWorkspace: need NRHS, prefer NRHS*NB) */ i__1 = *lwork - nwork + 1; zunmqr_("L", "C", m, nrhs, n, &a[a_offset], lda, &work[itau], &b[ b_offset], ldb, &work[nwork], &i__1, info); /* Zero out below R. */ if (*n > 1) { i__1 = *n - 1; i__2 = *n - 1; zlaset_("L", &i__1, &i__2, &c_b56, &c_b56, &a[a_dim1 + 2], lda); } } itauq = 1; itaup = itauq + *n; nwork = itaup + *n; ie = 1; nrwork = ie + *n; /* Bidiagonalize R in A. (RWorkspace: need N) (CWorkspace: need 2*N+MM, prefer 2*N+(MM+N)*NB) */ i__1 = *lwork - nwork + 1; zgebrd_(&mm, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[itauq], & work[itaup], &work[nwork], &i__1, info); /* Multiply B by transpose of left bidiagonalizing vectors of R. (CWorkspace: need 2*N+NRHS, prefer 2*N+NRHS*NB) */ i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "C", &mm, nrhs, n, &a[a_offset], lda, &work[itauq], &b[b_offset], ldb, &work[nwork], &i__1, info); /* Solve the bidiagonal least squares problem. */ zlalsd_("U", &smlsiz, n, nrhs, &s[1], &rwork[ie], &b[b_offset], ldb, rcond, rank, &work[nwork], &rwork[nrwork], &iwork[1], info); if (*info != 0) { goto L10; } /* Multiply B by right bidiagonalizing vectors of R. */ i__1 = *lwork - nwork + 1; zunmbr_("P", "L", "N", n, nrhs, n, &a[a_offset], lda, &work[itaup], & b[b_offset], ldb, &work[nwork], &i__1, info); } else /* if(complicated condition) */ { /* Computing MAX */ i__1 = *m, i__2 = (*m << 1) - 4, i__1 = max(i__1,i__2), i__1 = max( i__1,*nrhs), i__2 = *n - *m * 3; if (*n >= mnthr && *lwork >= (*m << 2) + *m * *m + max(i__1,i__2)) { /* Path 2a - underdetermined, with many more columns than rows and sufficient workspace for an efficient algorithm. */ ldwork = *m; /* Computing MAX Computing MAX */ i__3 = *m, i__4 = (*m << 1) - 4, i__3 = max(i__3,i__4), i__3 = max(i__3,*nrhs), i__4 = *n - *m * 3; i__1 = (*m << 2) + *m * *lda + max(i__3,i__4), i__2 = *m * *lda + *m + *m * *nrhs; if (*lwork >= max(i__1,i__2)) { ldwork = *lda; } itau = 1; nwork = *m + 1; /* Compute A=L*Q. (CWorkspace: need 2*M, prefer M+M*NB) */ i__1 = *lwork - nwork + 1; zgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], &i__1, info); il = nwork; /* Copy L to WORK(IL), zeroing out above its diagonal. */ zlacpy_("L", m, m, &a[a_offset], lda, &work[il], &ldwork); i__1 = *m - 1; i__2 = *m - 1; zlaset_("U", &i__1, &i__2, &c_b56, &c_b56, &work[il + ldwork], & ldwork); itauq = il + ldwork * *m; itaup = itauq + *m; nwork = itaup + *m; ie = 1; nrwork = ie + *m; /* Bidiagonalize L in WORK(IL). (RWorkspace: need M) (CWorkspace: need M*M+4*M, prefer M*M+4*M+2*M*NB) */ i__1 = *lwork - nwork + 1; zgebrd_(m, m, &work[il], &ldwork, &s[1], &rwork[ie], &work[itauq], &work[itaup], &work[nwork], &i__1, info); /* Multiply B by transpose of left bidiagonalizing vectors of L. (CWorkspace: need M*M+4*M+NRHS, prefer M*M+4*M+NRHS*NB) */ i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "C", m, nrhs, m, &work[il], &ldwork, &work[ itauq], &b[b_offset], ldb, &work[nwork], &i__1, info); /* Solve the bidiagonal least squares problem. */ zlalsd_("U", &smlsiz, m, nrhs, &s[1], &rwork[ie], &b[b_offset], ldb, rcond, rank, &work[nwork], &rwork[nrwork], &iwork[1], info); if (*info != 0) { goto L10; } /* Multiply B by right bidiagonalizing vectors of L. */ i__1 = *lwork - nwork + 1; zunmbr_("P", "L", "N", m, nrhs, m, &work[il], &ldwork, &work[ itaup], &b[b_offset], ldb, &work[nwork], &i__1, info); /* Zero out below first M rows of B. */ i__1 = *n - *m; zlaset_("F", &i__1, nrhs, &c_b56, &c_b56, &b[*m + 1 + b_dim1], ldb); nwork = itau + *m; /* Multiply transpose(Q) by B. (CWorkspace: need NRHS, prefer NRHS*NB) */ i__1 = *lwork - nwork + 1; zunmlq_("L", "C", n, nrhs, m, &a[a_offset], lda, &work[itau], &b[ b_offset], ldb, &work[nwork], &i__1, info); } else { /* Path 2 - remaining underdetermined cases. */ itauq = 1; itaup = itauq + *m; nwork = itaup + *m; ie = 1; nrwork = ie + *m; /* Bidiagonalize A. (RWorkspace: need M) (CWorkspace: need 2*M+N, prefer 2*M+(M+N)*NB) */ i__1 = *lwork - nwork + 1; zgebrd_(m, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[itauq], &work[itaup], &work[nwork], &i__1, info); /* Multiply B by transpose of left bidiagonalizing vectors. (CWorkspace: need 2*M+NRHS, prefer 2*M+NRHS*NB) */ i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "C", m, nrhs, n, &a[a_offset], lda, &work[itauq] , &b[b_offset], ldb, &work[nwork], &i__1, info); /* Solve the bidiagonal least squares problem. */ zlalsd_("L", &smlsiz, m, nrhs, &s[1], &rwork[ie], &b[b_offset], ldb, rcond, rank, &work[nwork], &rwork[nrwork], &iwork[1], info); if (*info != 0) { goto L10; } /* Multiply B by right bidiagonalizing vectors of A. */ i__1 = *lwork - nwork + 1; zunmbr_("P", "L", "N", n, nrhs, m, &a[a_offset], lda, &work[itaup] , &b[b_offset], ldb, &work[nwork], &i__1, info); } } /* Undo scaling. */ if (iascl == 1) { zlascl_("G", &c__0, &c__0, &anrm, &smlnum, n, nrhs, &b[b_offset], ldb, info); dlascl_("G", &c__0, &c__0, &smlnum, &anrm, &minmn, &c__1, &s[1], & minmn, info); } else if (iascl == 2) { zlascl_("G", &c__0, &c__0, &anrm, &bignum, n, nrhs, &b[b_offset], ldb, info); dlascl_("G", &c__0, &c__0, &bignum, &anrm, &minmn, &c__1, &s[1], & minmn, info); } if (ibscl == 1) { zlascl_("G", &c__0, &c__0, &smlnum, &bnrm, n, nrhs, &b[b_offset], ldb, info); } else if (ibscl == 2) { zlascl_("G", &c__0, &c__0, &bignum, &bnrm, n, nrhs, &b[b_offset], ldb, info); } L10: work[1].r = (doublereal) maxwrk, work[1].i = 0.; iwork[1] = liwork; rwork[1] = (doublereal) lrwork; return 0; /* End of ZGELSD */ } /* zgelsd_ */ /* Subroutine */ int zgeqr2_(integer *m, integer *n, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, k; static doublecomplex alpha; extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); /* -- LAPACK routine (version 3.2.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- June 2010 Purpose ======= ZGEQR2 computes a QR factorization of a complex m by n matrix A: A = Q * R. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the m by n matrix A. On exit, the elements on and above the diagonal of the array contain the min(m,n) by n upper trapezoidal matrix R (R is upper triangular if m >= n); the elements below the diagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors (see Further Details). LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). TAU (output) COMPLEX*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). WORK (workspace) COMPLEX*16 array, dimension (N) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== The matrix Q is represented as a product of elementary reflectors Q = H(1) H(2) . . . H(k), where k = min(m,n). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i), and tau in TAU(i). ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEQR2", &i__1); return 0; } k = min(*m,*n); i__1 = k; for (i__ = 1; i__ <= i__1; ++i__) { /* Generate elementary reflector H(i) to annihilate A(i+1:m,i) */ i__2 = *m - i__ + 1; /* Computing MIN */ i__3 = i__ + 1; zlarfg_(&i__2, &a[i__ + i__ * a_dim1], &a[min(i__3,*m) + i__ * a_dim1] , &c__1, &tau[i__]); if (i__ < *n) { /* Apply H(i)' to A(i:m,i+1:n) from the left */ i__2 = i__ + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; i__2 = *m - i__ + 1; i__3 = *n - i__; d_cnjg(&z__1, &tau[i__]); zlarf_("Left", &i__2, &i__3, &a[i__ + i__ * a_dim1], &c__1, &z__1, &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]); i__2 = i__ + i__ * a_dim1; a[i__2].r = alpha.r, a[i__2].i = alpha.i; } /* L10: */ } return 0; /* End of ZGEQR2 */ } /* zgeqr2_ */ /* Subroutine */ int zgeqrf_(integer *m, integer *n, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, k, ib, nb, nx, iws, nbmin, iinfo; extern /* Subroutine */ int zgeqr2_(integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), xerbla_( char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGEQRF computes a QR factorization of a complex M-by-N matrix A: A = Q * R. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, the elements on and above the diagonal of the array contain the min(M,N)-by-N upper trapezoidal matrix R (R is upper triangular if m >= n); the elements below the diagonal, with the array TAU, represent the unitary matrix Q as a product of min(m,n) elementary reflectors (see Further Details). LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). TAU (output) COMPLEX*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= N*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== The matrix Q is represented as a product of elementary reflectors Q = H(1) H(2) . . . H(k), where k = min(m,n). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i), and tau in TAU(i). ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; nb = ilaenv_(&c__1, "ZGEQRF", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen) 1); lwkopt = *n * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; lquery = *lwork == -1; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } else if (*lwork < max(1,*n) && ! lquery) { *info = -7; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGEQRF", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ k = min(*m,*n); if (k == 0) { work[1].r = 1., work[1].i = 0.; return 0; } nbmin = 2; nx = 0; iws = *n; if (nb > 1 && nb < k) { /* Determine when to cross over from blocked to unblocked code. Computing MAX */ i__1 = 0, i__2 = ilaenv_(&c__3, "ZGEQRF", " ", m, n, &c_n1, &c_n1, ( ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); if (nx < k) { /* Determine if workspace is large enough for blocked code. */ ldwork = *n; iws = ldwork * nb; if (*lwork < iws) { /* Not enough workspace to use optimal NB: reduce NB and determine the minimum value of NB. */ nb = *lwork / ldwork; /* Computing MAX */ i__1 = 2, i__2 = ilaenv_(&c__2, "ZGEQRF", " ", m, n, &c_n1, & c_n1, (ftnlen)6, (ftnlen)1); nbmin = max(i__1,i__2); } } } if (nb >= nbmin && nb < k && nx < k) { /* Use blocked code initially */ i__1 = k - nx; i__2 = nb; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = k - i__ + 1; ib = min(i__3,nb); /* Compute the QR factorization of the current block A(i:m,i:i+ib-1) */ i__3 = *m - i__ + 1; zgeqr2_(&i__3, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[ 1], &iinfo); if (i__ + ib <= *n) { /* Form the triangular factor of the block reflector H = H(i) H(i+1) . . . H(i+ib-1) */ i__3 = *m - i__ + 1; zlarft_("Forward", "Columnwise", &i__3, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[1], &ldwork); /* Apply H' to A(i:m,i+ib:n) from the left */ i__3 = *m - i__ + 1; i__4 = *n - i__ - ib + 1; zlarfb_("Left", "Conjugate transpose", "Forward", "Columnwise" , &i__3, &i__4, &ib, &a[i__ + i__ * a_dim1], lda, & work[1], &ldwork, &a[i__ + (i__ + ib) * a_dim1], lda, &work[ib + 1], &ldwork); } /* L10: */ } } else { i__ = 1; } /* Use unblocked code to factor the last or only block. */ if (i__ <= k) { i__2 = *m - i__ + 1; i__1 = *n - i__ + 1; zgeqr2_(&i__2, &i__1, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[1] , &iinfo); } work[1].r = (doublereal) iws, work[1].i = 0.; return 0; /* End of ZGEQRF */ } /* zgeqrf_ */ /* Subroutine */ int zgesdd_(char *jobz, integer *m, integer *n, doublecomplex *a, integer *lda, doublereal *s, doublecomplex *u, integer *ldu, doublecomplex *vt, integer *ldvt, doublecomplex *work, integer *lwork, doublereal *rwork, integer *iwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, u_dim1, u_offset, vt_dim1, vt_offset, i__1, i__2, i__3; /* Builtin functions */ double sqrt(doublereal); /* Local variables */ static integer i__, ie, il, ir, iu, blk; static doublereal dum[1], eps; static integer iru, ivt, iscl; static doublereal anrm; static integer idum[1], ierr, itau, irvt; extern logical lsame_(char *, char *); static integer chunk, minmn; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer wrkbl, itaup, itauq; static logical wntqa; static integer nwork; static logical wntqn, wntqo, wntqs; extern /* Subroutine */ int zlacp2_(char *, integer *, integer *, doublereal *, integer *, doublecomplex *, integer *); static integer mnthr1, mnthr2; extern /* Subroutine */ int dbdsdc_(char *, char *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, integer *); extern /* Subroutine */ int dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *), xerbla_(char *, integer *), zgebrd_(integer *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, doublecomplex *, doublecomplex *, doublecomplex *, integer *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static doublereal bignum; extern doublereal zlange_(char *, integer *, integer *, doublecomplex *, integer *, doublereal *); extern /* Subroutine */ int zgelqf_(integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer * ), zlacrm_(integer *, integer *, doublecomplex *, integer *, doublereal *, integer *, doublecomplex *, integer *, doublereal *) , zlarcm_(integer *, integer *, doublereal *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *), zlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublecomplex *, integer *, integer *), zgeqrf_(integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer * ); static integer ldwrkl; extern /* Subroutine */ int zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static integer ldwrkr, minwrk, ldwrku, maxwrk; extern /* Subroutine */ int zungbr_(char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); static integer ldwkvt; static doublereal smlnum; static logical wntqas; extern /* Subroutine */ int zunmbr_(char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer * ), zunglq_(integer *, integer *, integer * , doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); static integer nrwork; extern /* Subroutine */ int zungqr_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); /* -- LAPACK driver routine (version 3.2.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- June 2010 8-15-00: Improve consistency of WS calculations (eca) Purpose ======= ZGESDD computes the singular value decomposition (SVD) of a complex M-by-N matrix A, optionally computing the left and/or right singular vectors, by using divide-and-conquer method. The SVD is written A = U * SIGMA * conjugate-transpose(V) where SIGMA is an M-by-N matrix which is zero except for its min(m,n) diagonal elements, U is an M-by-M unitary matrix, and V is an N-by-N unitary matrix. The diagonal elements of SIGMA are the singular values of A; they are real and non-negative, and are returned in descending order. The first min(m,n) columns of U and V are the left and right singular vectors of A. Note that the routine returns VT = V**H, not V. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= JOBZ (input) CHARACTER*1 Specifies options for computing all or part of the matrix U: = 'A': all M columns of U and all N rows of V**H are returned in the arrays U and VT; = 'S': the first min(M,N) columns of U and the first min(M,N) rows of V**H are returned in the arrays U and VT; = 'O': If M >= N, the first N columns of U are overwritten in the array A and all rows of V**H are returned in the array VT; otherwise, all columns of U are returned in the array U and the first M rows of V**H are overwritten in the array A; = 'N': no columns of U or rows of V**H are computed. M (input) INTEGER The number of rows of the input matrix A. M >= 0. N (input) INTEGER The number of columns of the input matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, if JOBZ = 'O', A is overwritten with the first N columns of U (the left singular vectors, stored columnwise) if M >= N; A is overwritten with the first M rows of V**H (the right singular vectors, stored rowwise) otherwise. if JOBZ .ne. 'O', the contents of A are destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). S (output) DOUBLE PRECISION array, dimension (min(M,N)) The singular values of A, sorted so that S(i) >= S(i+1). U (output) COMPLEX*16 array, dimension (LDU,UCOL) UCOL = M if JOBZ = 'A' or JOBZ = 'O' and M < N; UCOL = min(M,N) if JOBZ = 'S'. If JOBZ = 'A' or JOBZ = 'O' and M < N, U contains the M-by-M unitary matrix U; if JOBZ = 'S', U contains the first min(M,N) columns of U (the left singular vectors, stored columnwise); if JOBZ = 'O' and M >= N, or JOBZ = 'N', U is not referenced. LDU (input) INTEGER The leading dimension of the array U. LDU >= 1; if JOBZ = 'S' or 'A' or JOBZ = 'O' and M < N, LDU >= M. VT (output) COMPLEX*16 array, dimension (LDVT,N) If JOBZ = 'A' or JOBZ = 'O' and M >= N, VT contains the N-by-N unitary matrix V**H; if JOBZ = 'S', VT contains the first min(M,N) rows of V**H (the right singular vectors, stored rowwise); if JOBZ = 'O' and M < N, or JOBZ = 'N', VT is not referenced. LDVT (input) INTEGER The leading dimension of the array VT. LDVT >= 1; if JOBZ = 'A' or JOBZ = 'O' and M >= N, LDVT >= N; if JOBZ = 'S', LDVT >= min(M,N). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= 1. if JOBZ = 'N', LWORK >= 2*min(M,N)+max(M,N). if JOBZ = 'O', LWORK >= 2*min(M,N)*min(M,N)+2*min(M,N)+max(M,N). if JOBZ = 'S' or 'A', LWORK >= min(M,N)*min(M,N)+2*min(M,N)+max(M,N). For good performance, LWORK should generally be larger. If LWORK = -1, a workspace query is assumed. The optimal size for the WORK array is calculated and stored in WORK(1), and no other work except argument checking is performed. RWORK (workspace) DOUBLE PRECISION array, dimension (MAX(1,LRWORK)) If JOBZ = 'N', LRWORK >= 5*min(M,N). Otherwise, LRWORK >= min(M,N)*max(5*min(M,N)+7,2*max(M,N)+2*min(M,N)+1) IWORK (workspace) INTEGER array, dimension (8*min(M,N)) INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: The updating process of DBDSDC did not converge. Further Details =============== Based on contributions by Ming Gu and Huan Ren, Computer Science Division, University of California at Berkeley, USA ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --s; u_dim1 = *ldu; u_offset = 1 + u_dim1; u -= u_offset; vt_dim1 = *ldvt; vt_offset = 1 + vt_dim1; vt -= vt_offset; --work; --rwork; --iwork; /* Function Body */ *info = 0; minmn = min(*m,*n); mnthr1 = (integer) (minmn * 17. / 9.); mnthr2 = (integer) (minmn * 5. / 3.); wntqa = lsame_(jobz, "A"); wntqs = lsame_(jobz, "S"); wntqas = wntqa || wntqs; wntqo = lsame_(jobz, "O"); wntqn = lsame_(jobz, "N"); minwrk = 1; maxwrk = 1; if (! (wntqa || wntqs || wntqo || wntqn)) { *info = -1; } else if (*m < 0) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } else if (*ldu < 1 || wntqas && *ldu < *m || wntqo && *m < *n && *ldu < * m) { *info = -8; } else if (*ldvt < 1 || wntqa && *ldvt < *n || wntqs && *ldvt < minmn || wntqo && *m >= *n && *ldvt < *n) { *info = -10; } /* Compute workspace (Note: Comments in the code beginning "Workspace:" describe the minimal amount of workspace needed at that point in the code, as well as the preferred amount for good performance. CWorkspace refers to complex workspace, and RWorkspace to real workspace. NB refers to the optimal block size for the immediately following subroutine, as returned by ILAENV.) */ if (*info == 0 && *m > 0 && *n > 0) { if (*m >= *n) { /* There is no complex work space needed for bidiagonal SVD The real work space needed for bidiagonal SVD is BDSPAC for computing singular values and singular vectors; BDSPAN for computing singular values only. BDSPAC = 5*N*N + 7*N BDSPAN = MAX(7*N+4, 3*N+2+SMLSIZ*(SMLSIZ+8)) */ if (*m >= mnthr1) { if (wntqn) { /* Path 1 (M much larger than N, JOBZ='N') */ maxwrk = *n + *n * ilaenv_(&c__1, "ZGEQRF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + (*n << 1) * ilaenv_(& c__1, "ZGEBRD", " ", n, n, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); maxwrk = max(i__1,i__2); minwrk = *n * 3; } else if (wntqo) { /* Path 2 (M much larger than N, JOBZ='O') */ wrkbl = *n + *n * ilaenv_(&c__1, "ZGEQRF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n + *n * ilaenv_(&c__1, "ZUNGQR", " ", m, n, n, &c_n1, (ftnlen)6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + (*n << 1) * ilaenv_(& c__1, "ZGEBRD", " ", n, n, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "QLN", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "PRC", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); maxwrk = *m * *n + *n * *n + wrkbl; minwrk = (*n << 1) * *n + *n * 3; } else if (wntqs) { /* Path 3 (M much larger than N, JOBZ='S') */ wrkbl = *n + *n * ilaenv_(&c__1, "ZGEQRF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n + *n * ilaenv_(&c__1, "ZUNGQR", " ", m, n, n, &c_n1, (ftnlen)6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + (*n << 1) * ilaenv_(& c__1, "ZGEBRD", " ", n, n, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "QLN", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "PRC", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); maxwrk = *n * *n + wrkbl; minwrk = *n * *n + *n * 3; } else if (wntqa) { /* Path 4 (M much larger than N, JOBZ='A') */ wrkbl = *n + *n * ilaenv_(&c__1, "ZGEQRF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = wrkbl, i__2 = *n + *m * ilaenv_(&c__1, "ZUNGQR", " ", m, m, n, &c_n1, (ftnlen)6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + (*n << 1) * ilaenv_(& c__1, "ZGEBRD", " ", n, n, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "QLN", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "PRC", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); maxwrk = *n * *n + wrkbl; minwrk = *n * *n + (*n << 1) + *m; } } else if (*m >= mnthr2) { /* Path 5 (M much larger than N, but not as much as MNTHR1) */ maxwrk = (*n << 1) + (*m + *n) * ilaenv_(&c__1, "ZGEBRD", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); minwrk = (*n << 1) + *m; if (wntqo) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "P", n, n, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "Q", m, n, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); maxwrk += *m * *n; minwrk += *n * *n; } else if (wntqs) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "P", n, n, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "Q", m, n, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); } else if (wntqa) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "P", n, n, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "Q", m, m, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); } } else { /* Path 6 (M at least N, but not much larger) */ maxwrk = (*n << 1) + (*m + *n) * ilaenv_(&c__1, "ZGEBRD", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); minwrk = (*n << 1) + *m; if (wntqo) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "PRC", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "QLN", m, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); maxwrk += *m * *n; minwrk += *n * *n; } else if (wntqs) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "PRC", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNMBR", "QLN", m, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); } else if (wntqa) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "PRC", n, n, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*n << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "QLN", m, m, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); } } } else { /* There is no complex work space needed for bidiagonal SVD The real work space needed for bidiagonal SVD is BDSPAC for computing singular values and singular vectors; BDSPAN for computing singular values only. BDSPAC = 5*M*M + 7*M BDSPAN = MAX(7*M+4, 3*M+2+SMLSIZ*(SMLSIZ+8)) */ if (*n >= mnthr1) { if (wntqn) { /* Path 1t (N much larger than M, JOBZ='N') */ maxwrk = *m + *m * ilaenv_(&c__1, "ZGELQF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + (*m << 1) * ilaenv_(& c__1, "ZGEBRD", " ", m, m, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); maxwrk = max(i__1,i__2); minwrk = *m * 3; } else if (wntqo) { /* Path 2t (N much larger than M, JOBZ='O') */ wrkbl = *m + *m * ilaenv_(&c__1, "ZGELQF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m + *m * ilaenv_(&c__1, "ZUNGLQ", " ", m, n, m, &c_n1, (ftnlen)6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + (*m << 1) * ilaenv_(& c__1, "ZGEBRD", " ", m, m, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "PRC", m, m, m, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "QLN", m, m, m, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); maxwrk = *m * *n + *m * *m + wrkbl; minwrk = (*m << 1) * *m + *m * 3; } else if (wntqs) { /* Path 3t (N much larger than M, JOBZ='S') */ wrkbl = *m + *m * ilaenv_(&c__1, "ZGELQF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m + *m * ilaenv_(&c__1, "ZUNGLQ", " ", m, n, m, &c_n1, (ftnlen)6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + (*m << 1) * ilaenv_(& c__1, "ZGEBRD", " ", m, m, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "PRC", m, m, m, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "QLN", m, m, m, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); maxwrk = *m * *m + wrkbl; minwrk = *m * *m + *m * 3; } else if (wntqa) { /* Path 4t (N much larger than M, JOBZ='A') */ wrkbl = *m + *m * ilaenv_(&c__1, "ZGELQF", " ", m, n, & c_n1, &c_n1, (ftnlen)6, (ftnlen)1); /* Computing MAX */ i__1 = wrkbl, i__2 = *m + *n * ilaenv_(&c__1, "ZUNGLQ", " ", n, n, m, &c_n1, (ftnlen)6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + (*m << 1) * ilaenv_(& c__1, "ZGEBRD", " ", m, m, &c_n1, &c_n1, (ftnlen) 6, (ftnlen)1); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "PRC", m, m, m, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); /* Computing MAX */ i__1 = wrkbl, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "QLN", m, m, m, &c_n1, (ftnlen)6, ( ftnlen)3); wrkbl = max(i__1,i__2); maxwrk = *m * *m + wrkbl; minwrk = *m * *m + (*m << 1) + *n; } } else if (*n >= mnthr2) { /* Path 5t (N much larger than M, but not as much as MNTHR1) */ maxwrk = (*m << 1) + (*m + *n) * ilaenv_(&c__1, "ZGEBRD", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); minwrk = (*m << 1) + *n; if (wntqo) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "P", m, n, m, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "Q", m, m, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); maxwrk += *m * *n; minwrk += *m * *m; } else if (wntqs) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "P", m, n, m, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "Q", m, m, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); } else if (wntqa) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "P", n, n, m, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "Q", m, m, n, &c_n1, (ftnlen)6, (ftnlen) 1); maxwrk = max(i__1,i__2); } } else { /* Path 6t (N greater than M, but not much larger) */ maxwrk = (*m << 1) + (*m + *n) * ilaenv_(&c__1, "ZGEBRD", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); minwrk = (*m << 1) + *n; if (wntqo) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "PRC", m, n, m, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNMBR", "QLN", m, m, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); maxwrk += *m * *n; minwrk += *m * *m; } else if (wntqs) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "PRC", m, n, m, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "QLN", m, m, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); } else if (wntqa) { /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *n * ilaenv_(&c__1, "ZUNGBR", "PRC", n, n, m, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); /* Computing MAX */ i__1 = maxwrk, i__2 = (*m << 1) + *m * ilaenv_(&c__1, "ZUNGBR", "QLN", m, m, n, &c_n1, (ftnlen)6, ( ftnlen)3); maxwrk = max(i__1,i__2); } } } maxwrk = max(maxwrk,minwrk); } if (*info == 0) { work[1].r = (doublereal) maxwrk, work[1].i = 0.; if (*lwork < minwrk && *lwork != -1) { *info = -13; } } /* Quick returns */ if (*info != 0) { i__1 = -(*info); xerbla_("ZGESDD", &i__1); return 0; } if (*lwork == -1) { return 0; } if (*m == 0 || *n == 0) { return 0; } /* Get machine constants */ eps = PRECISION; smlnum = sqrt(SAFEMINIMUM) / eps; bignum = 1. / smlnum; /* Scale A if max element outside range [SMLNUM,BIGNUM] */ anrm = zlange_("M", m, n, &a[a_offset], lda, dum); iscl = 0; if (anrm > 0. && anrm < smlnum) { iscl = 1; zlascl_("G", &c__0, &c__0, &anrm, &smlnum, m, n, &a[a_offset], lda, & ierr); } else if (anrm > bignum) { iscl = 1; zlascl_("G", &c__0, &c__0, &anrm, &bignum, m, n, &a[a_offset], lda, & ierr); } if (*m >= *n) { /* A has at least as many rows as columns. If A has sufficiently more rows than columns, first reduce using the QR decomposition (if sufficient workspace available) */ if (*m >= mnthr1) { if (wntqn) { /* Path 1 (M much larger than N, JOBZ='N') No singular vectors to be computed */ itau = 1; nwork = itau + *n; /* Compute A=Q*R (CWorkspace: need 2*N, prefer N+N*NB) (RWorkspace: need 0) */ i__1 = *lwork - nwork + 1; zgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Zero out below R */ i__1 = *n - 1; i__2 = *n - 1; zlaset_("L", &i__1, &i__2, &c_b56, &c_b56, &a[a_dim1 + 2], lda); ie = 1; itauq = 1; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in A (CWorkspace: need 3*N, prefer 2*N+2*N*NB) (RWorkspace: need N) */ i__1 = *lwork - nwork + 1; zgebrd_(n, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); nrwork = ie + *n; /* Perform bidiagonal SVD, compute singular values only (CWorkspace: 0) (RWorkspace: need BDSPAN) */ dbdsdc_("U", "N", n, &s[1], &rwork[ie], dum, &c__1, dum, & c__1, dum, idum, &rwork[nrwork], &iwork[1], info); } else if (wntqo) { /* Path 2 (M much larger than N, JOBZ='O') N left singular vectors to be overwritten on A and N right singular vectors to be computed in VT */ iu = 1; /* WORK(IU) is N by N */ ldwrku = *n; ir = iu + ldwrku * *n; if (*lwork >= *m * *n + *n * *n + *n * 3) { /* WORK(IR) is M by N */ ldwrkr = *m; } else { ldwrkr = (*lwork - *n * *n - *n * 3) / *n; } itau = ir + ldwrkr * *n; nwork = itau + *n; /* Compute A=Q*R (CWorkspace: need N*N+2*N, prefer M*N+N+N*NB) (RWorkspace: 0) */ i__1 = *lwork - nwork + 1; zgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Copy R to WORK( IR ), zeroing out below it */ zlacpy_("U", n, n, &a[a_offset], lda, &work[ir], &ldwrkr); i__1 = *n - 1; i__2 = *n - 1; zlaset_("L", &i__1, &i__2, &c_b56, &c_b56, &work[ir + 1], & ldwrkr); /* Generate Q in A (CWorkspace: need 2*N, prefer N+N*NB) (RWorkspace: 0) */ i__1 = *lwork - nwork + 1; zungqr_(m, n, n, &a[a_offset], lda, &work[itau], &work[nwork], &i__1, &ierr); ie = 1; itauq = itau; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in WORK(IR) (CWorkspace: need N*N+3*N, prefer M*N+2*N+2*N*NB) (RWorkspace: need N) */ i__1 = *lwork - nwork + 1; zgebrd_(n, n, &work[ir], &ldwrkr, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of R in WORK(IRU) and computing right singular vectors of R in WORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = ie + *n; irvt = iru + *n * *n; nrwork = irvt + *n * *n; dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix WORK(IU) Overwrite WORK(IU) by the left singular vectors of R (CWorkspace: need 2*N*N+3*N, prefer M*N+N*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[iru], n, &work[iu], &ldwrku); i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", n, n, n, &work[ir], &ldwrkr, &work[ itauq], &work[iu], &ldwrku, &work[nwork], &i__1, & ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by the right singular vectors of R (CWorkspace: need N*N+3*N, prefer M*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[irvt], n, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, n, &work[ir], &ldwrkr, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); /* Multiply Q in A by left singular vectors of R in WORK(IU), storing result in WORK(IR) and copying to A (CWorkspace: need 2*N*N, prefer N*N+M*N) (RWorkspace: 0) */ i__1 = *m; i__2 = ldwrkr; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = *m - i__ + 1; chunk = min(i__3,ldwrkr); zgemm_("N", "N", &chunk, n, n, &c_b57, &a[i__ + a_dim1], lda, &work[iu], &ldwrku, &c_b56, &work[ir], & ldwrkr); zlacpy_("F", &chunk, n, &work[ir], &ldwrkr, &a[i__ + a_dim1], lda); /* L10: */ } } else if (wntqs) { /* Path 3 (M much larger than N, JOBZ='S') N left singular vectors to be computed in U and N right singular vectors to be computed in VT */ ir = 1; /* WORK(IR) is N by N */ ldwrkr = *n; itau = ir + ldwrkr * *n; nwork = itau + *n; /* Compute A=Q*R (CWorkspace: need N*N+2*N, prefer N*N+N+N*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); /* Copy R to WORK(IR), zeroing out below it */ zlacpy_("U", n, n, &a[a_offset], lda, &work[ir], &ldwrkr); i__2 = *n - 1; i__1 = *n - 1; zlaset_("L", &i__2, &i__1, &c_b56, &c_b56, &work[ir + 1], & ldwrkr); /* Generate Q in A (CWorkspace: need 2*N, prefer N+N*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zungqr_(m, n, n, &a[a_offset], lda, &work[itau], &work[nwork], &i__2, &ierr); ie = 1; itauq = itau; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in WORK(IR) (CWorkspace: need N*N+3*N, prefer N*N+2*N+2*N*NB) (RWorkspace: need N) */ i__2 = *lwork - nwork + 1; zgebrd_(n, n, &work[ir], &ldwrkr, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = ie + *n; irvt = iru + *n * *n; nrwork = irvt + *n * *n; dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of R (CWorkspace: need N*N+3*N, prefer N*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[iru], n, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", n, n, n, &work[ir], &ldwrkr, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of R (CWorkspace: need N*N+3*N, prefer N*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[irvt], n, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, n, &work[ir], &ldwrkr, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); /* Multiply Q in A by left singular vectors of R in WORK(IR), storing result in U (CWorkspace: need N*N) (RWorkspace: 0) */ zlacpy_("F", n, n, &u[u_offset], ldu, &work[ir], &ldwrkr); zgemm_("N", "N", m, n, n, &c_b57, &a[a_offset], lda, &work[ir] , &ldwrkr, &c_b56, &u[u_offset], ldu); } else if (wntqa) { /* Path 4 (M much larger than N, JOBZ='A') M left singular vectors to be computed in U and N right singular vectors to be computed in VT */ iu = 1; /* WORK(IU) is N by N */ ldwrku = *n; itau = iu + ldwrku * *n; nwork = itau + *n; /* Compute A=Q*R, copying result to U (CWorkspace: need 2*N, prefer N+N*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zgeqrf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); zlacpy_("L", m, n, &a[a_offset], lda, &u[u_offset], ldu); /* Generate Q in U (CWorkspace: need N+M, prefer N+M*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zungqr_(m, m, n, &u[u_offset], ldu, &work[itau], &work[nwork], &i__2, &ierr); /* Produce R in A, zeroing out below it */ i__2 = *n - 1; i__1 = *n - 1; zlaset_("L", &i__2, &i__1, &c_b56, &c_b56, &a[a_dim1 + 2], lda); ie = 1; itauq = itau; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize R in A (CWorkspace: need 3*N, prefer 2*N+2*N*NB) (RWorkspace: need N) */ i__2 = *lwork - nwork + 1; zgebrd_(n, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); iru = ie + *n; irvt = iru + *n * *n; nrwork = irvt + *n * *n; /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix WORK(IU) Overwrite WORK(IU) by left singular vectors of R (CWorkspace: need N*N+3*N, prefer N*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[iru], n, &work[iu], &ldwrku); i__2 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", n, n, n, &a[a_offset], lda, &work[ itauq], &work[iu], &ldwrku, &work[nwork], &i__2, & ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of R (CWorkspace: need 3*N, prefer 2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[irvt], n, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); /* Multiply Q in U by left singular vectors of R in WORK(IU), storing result in A (CWorkspace: need N*N) (RWorkspace: 0) */ zgemm_("N", "N", m, n, n, &c_b57, &u[u_offset], ldu, &work[iu] , &ldwrku, &c_b56, &a[a_offset], lda); /* Copy left singular vectors of A from A to U */ zlacpy_("F", m, n, &a[a_offset], lda, &u[u_offset], ldu); } } else if (*m >= mnthr2) { /* MNTHR2 <= M < MNTHR1 Path 5 (M much larger than N, but not as much as MNTHR1) Reduce to bidiagonal form without QR decomposition, use ZUNGBR and matrix multiplication to compute singular vectors */ ie = 1; nrwork = ie + *n; itauq = 1; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize A (CWorkspace: need 2*N+M, prefer 2*N+(M+N)*NB) (RWorkspace: need N) */ i__2 = *lwork - nwork + 1; zgebrd_(m, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[itauq], &work[itaup], &work[nwork], &i__2, &ierr); if (wntqn) { /* Compute singular values only (Cworkspace: 0) (Rworkspace: need BDSPAN) */ dbdsdc_("U", "N", n, &s[1], &rwork[ie], dum, &c__1, dum, & c__1, dum, idum, &rwork[nrwork], &iwork[1], info); } else if (wntqo) { iu = nwork; iru = nrwork; irvt = iru + *n * *n; nrwork = irvt + *n * *n; /* Copy A to VT, generate P**H (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: 0) */ zlacpy_("U", n, n, &a[a_offset], lda, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zungbr_("P", n, n, n, &vt[vt_offset], ldvt, &work[itaup], & work[nwork], &i__2, &ierr); /* Generate Q in A (CWorkspace: need 2*N, prefer N+N*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zungbr_("Q", m, n, n, &a[a_offset], lda, &work[itauq], &work[ nwork], &i__2, &ierr); if (*lwork >= *m * *n + *n * 3) { /* WORK( IU ) is M by N */ ldwrku = *m; } else { /* WORK(IU) is LDWRKU by N */ ldwrku = (*lwork - *n * 3) / *n; } nwork = iu + ldwrku * *n; /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Multiply real matrix RWORK(IRVT) by P**H in VT, storing the result in WORK(IU), copying to VT (Cworkspace: need 0) (Rworkspace: need 3*N*N) */ zlarcm_(n, n, &rwork[irvt], n, &vt[vt_offset], ldvt, &work[iu] , &ldwrku, &rwork[nrwork]); zlacpy_("F", n, n, &work[iu], &ldwrku, &vt[vt_offset], ldvt); /* Multiply Q in A by real matrix RWORK(IRU), storing the result in WORK(IU), copying to A (CWorkspace: need N*N, prefer M*N) (Rworkspace: need 3*N*N, prefer N*N+2*M*N) */ nrwork = irvt; i__2 = *m; i__1 = ldwrku; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Computing MIN */ i__3 = *m - i__ + 1; chunk = min(i__3,ldwrku); zlacrm_(&chunk, n, &a[i__ + a_dim1], lda, &rwork[iru], n, &work[iu], &ldwrku, &rwork[nrwork]); zlacpy_("F", &chunk, n, &work[iu], &ldwrku, &a[i__ + a_dim1], lda); /* L20: */ } } else if (wntqs) { /* Copy A to VT, generate P**H (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: 0) */ zlacpy_("U", n, n, &a[a_offset], lda, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zungbr_("P", n, n, n, &vt[vt_offset], ldvt, &work[itaup], & work[nwork], &i__1, &ierr); /* Copy A to U, generate Q (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: 0) */ zlacpy_("L", m, n, &a[a_offset], lda, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zungbr_("Q", m, n, n, &u[u_offset], ldu, &work[itauq], &work[ nwork], &i__1, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = nrwork; irvt = iru + *n * *n; nrwork = irvt + *n * *n; dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Multiply real matrix RWORK(IRVT) by P**H in VT, storing the result in A, copying to VT (Cworkspace: need 0) (Rworkspace: need 3*N*N) */ zlarcm_(n, n, &rwork[irvt], n, &vt[vt_offset], ldvt, &a[ a_offset], lda, &rwork[nrwork]); zlacpy_("F", n, n, &a[a_offset], lda, &vt[vt_offset], ldvt); /* Multiply Q in U by real matrix RWORK(IRU), storing the result in A, copying to U (CWorkspace: need 0) (Rworkspace: need N*N+2*M*N) */ nrwork = irvt; zlacrm_(m, n, &u[u_offset], ldu, &rwork[iru], n, &a[a_offset], lda, &rwork[nrwork]); zlacpy_("F", m, n, &a[a_offset], lda, &u[u_offset], ldu); } else { /* Copy A to VT, generate P**H (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: 0) */ zlacpy_("U", n, n, &a[a_offset], lda, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zungbr_("P", n, n, n, &vt[vt_offset], ldvt, &work[itaup], & work[nwork], &i__1, &ierr); /* Copy A to U, generate Q (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: 0) */ zlacpy_("L", m, n, &a[a_offset], lda, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zungbr_("Q", m, m, n, &u[u_offset], ldu, &work[itauq], &work[ nwork], &i__1, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = nrwork; irvt = iru + *n * *n; nrwork = irvt + *n * *n; dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Multiply real matrix RWORK(IRVT) by P**H in VT, storing the result in A, copying to VT (Cworkspace: need 0) (Rworkspace: need 3*N*N) */ zlarcm_(n, n, &rwork[irvt], n, &vt[vt_offset], ldvt, &a[ a_offset], lda, &rwork[nrwork]); zlacpy_("F", n, n, &a[a_offset], lda, &vt[vt_offset], ldvt); /* Multiply Q in U by real matrix RWORK(IRU), storing the result in A, copying to U (CWorkspace: 0) (Rworkspace: need 3*N*N) */ nrwork = irvt; zlacrm_(m, n, &u[u_offset], ldu, &rwork[iru], n, &a[a_offset], lda, &rwork[nrwork]); zlacpy_("F", m, n, &a[a_offset], lda, &u[u_offset], ldu); } } else { /* M .LT. MNTHR2 Path 6 (M at least N, but not much larger) Reduce to bidiagonal form without QR decomposition Use ZUNMBR to compute singular vectors */ ie = 1; nrwork = ie + *n; itauq = 1; itaup = itauq + *n; nwork = itaup + *n; /* Bidiagonalize A (CWorkspace: need 2*N+M, prefer 2*N+(M+N)*NB) (RWorkspace: need N) */ i__1 = *lwork - nwork + 1; zgebrd_(m, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[itauq], &work[itaup], &work[nwork], &i__1, &ierr); if (wntqn) { /* Compute singular values only (Cworkspace: 0) (Rworkspace: need BDSPAN) */ dbdsdc_("U", "N", n, &s[1], &rwork[ie], dum, &c__1, dum, & c__1, dum, idum, &rwork[nrwork], &iwork[1], info); } else if (wntqo) { iu = nwork; iru = nrwork; irvt = iru + *n * *n; nrwork = irvt + *n * *n; if (*lwork >= *m * *n + *n * 3) { /* WORK( IU ) is M by N */ ldwrku = *m; } else { /* WORK( IU ) is LDWRKU by N */ ldwrku = (*lwork - *n * 3) / *n; } nwork = iu + ldwrku * *n; /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of A (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: need 0) */ zlacp2_("F", n, n, &rwork[irvt], n, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); if (*lwork >= *m * *n + *n * 3) { /* Copy real matrix RWORK(IRU) to complex matrix WORK(IU) Overwrite WORK(IU) by left singular vectors of A, copying to A (Cworkspace: need M*N+2*N, prefer M*N+N+N*NB) (Rworkspace: need 0) */ zlaset_("F", m, n, &c_b56, &c_b56, &work[iu], &ldwrku); zlacp2_("F", n, n, &rwork[iru], n, &work[iu], &ldwrku); i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, n, n, &a[a_offset], lda, &work[ itauq], &work[iu], &ldwrku, &work[nwork], &i__1, & ierr); zlacpy_("F", m, n, &work[iu], &ldwrku, &a[a_offset], lda); } else { /* Generate Q in A (Cworkspace: need 2*N, prefer N+N*NB) (Rworkspace: need 0) */ i__1 = *lwork - nwork + 1; zungbr_("Q", m, n, n, &a[a_offset], lda, &work[itauq], & work[nwork], &i__1, &ierr); /* Multiply Q in A by real matrix RWORK(IRU), storing the result in WORK(IU), copying to A (CWorkspace: need N*N, prefer M*N) (Rworkspace: need 3*N*N, prefer N*N+2*M*N) */ nrwork = irvt; i__1 = *m; i__2 = ldwrku; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = *m - i__ + 1; chunk = min(i__3,ldwrku); zlacrm_(&chunk, n, &a[i__ + a_dim1], lda, &rwork[iru], n, &work[iu], &ldwrku, &rwork[nrwork]); zlacpy_("F", &chunk, n, &work[iu], &ldwrku, &a[i__ + a_dim1], lda); /* L30: */ } } } else if (wntqs) { /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = nrwork; irvt = iru + *n * *n; nrwork = irvt + *n * *n; dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of A (CWorkspace: need 3*N, prefer 2*N+N*NB) (RWorkspace: 0) */ zlaset_("F", m, n, &c_b56, &c_b56, &u[u_offset], ldu); zlacp2_("F", n, n, &rwork[iru], n, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, n, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of A (CWorkspace: need 3*N, prefer 2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[irvt], n, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); } else { /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = nrwork; irvt = iru + *n * *n; nrwork = irvt + *n * *n; dbdsdc_("U", "I", n, &s[1], &rwork[ie], &rwork[iru], n, & rwork[irvt], n, dum, idum, &rwork[nrwork], &iwork[1], info); /* Set the right corner of U to identity matrix */ zlaset_("F", m, m, &c_b56, &c_b56, &u[u_offset], ldu); if (*m > *n) { i__2 = *m - *n; i__1 = *m - *n; zlaset_("F", &i__2, &i__1, &c_b56, &c_b57, &u[*n + 1 + (* n + 1) * u_dim1], ldu); } /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of A (CWorkspace: need 2*N+M, prefer 2*N+M*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[iru], n, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of A (CWorkspace: need 3*N, prefer 2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", n, n, &rwork[irvt], n, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, n, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__2, & ierr); } } } else { /* A has more columns than rows. If A has sufficiently more columns than rows, first reduce using the LQ decomposition (if sufficient workspace available) */ if (*n >= mnthr1) { if (wntqn) { /* Path 1t (N much larger than M, JOBZ='N') No singular vectors to be computed */ itau = 1; nwork = itau + *m; /* Compute A=L*Q (CWorkspace: need 2*M, prefer M+M*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); /* Zero out above L */ i__2 = *m - 1; i__1 = *m - 1; zlaset_("U", &i__2, &i__1, &c_b56, &c_b56, &a[(a_dim1 << 1) + 1], lda); ie = 1; itauq = 1; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in A (CWorkspace: need 3*M, prefer 2*M+2*M*NB) (RWorkspace: need M) */ i__2 = *lwork - nwork + 1; zgebrd_(m, m, &a[a_offset], lda, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); nrwork = ie + *m; /* Perform bidiagonal SVD, compute singular values only (CWorkspace: 0) (RWorkspace: need BDSPAN) */ dbdsdc_("U", "N", m, &s[1], &rwork[ie], dum, &c__1, dum, & c__1, dum, idum, &rwork[nrwork], &iwork[1], info); } else if (wntqo) { /* Path 2t (N much larger than M, JOBZ='O') M right singular vectors to be overwritten on A and M left singular vectors to be computed in U */ ivt = 1; ldwkvt = *m; /* WORK(IVT) is M by M */ il = ivt + ldwkvt * *m; if (*lwork >= *m * *n + *m * *m + *m * 3) { /* WORK(IL) M by N */ ldwrkl = *m; chunk = *n; } else { /* WORK(IL) is M by CHUNK */ ldwrkl = *m; chunk = (*lwork - *m * *m - *m * 3) / *m; } itau = il + ldwrkl * chunk; nwork = itau + *m; /* Compute A=L*Q (CWorkspace: need 2*M, prefer M+M*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__2, &ierr); /* Copy L to WORK(IL), zeroing about above it */ zlacpy_("L", m, m, &a[a_offset], lda, &work[il], &ldwrkl); i__2 = *m - 1; i__1 = *m - 1; zlaset_("U", &i__2, &i__1, &c_b56, &c_b56, &work[il + ldwrkl], &ldwrkl); /* Generate Q in A (CWorkspace: need M*M+2*M, prefer M*M+M+M*NB) (RWorkspace: 0) */ i__2 = *lwork - nwork + 1; zunglq_(m, n, m, &a[a_offset], lda, &work[itau], &work[nwork], &i__2, &ierr); ie = 1; itauq = itau; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in WORK(IL) (CWorkspace: need M*M+3*M, prefer M*M+2*M+2*M*NB) (RWorkspace: need M) */ i__2 = *lwork - nwork + 1; zgebrd_(m, m, &work[il], &ldwrkl, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = ie + *m; irvt = iru + *m * *m; nrwork = irvt + *m * *m; dbdsdc_("U", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix WORK(IU) Overwrite WORK(IU) by the left singular vectors of L (CWorkspace: need N*N+3*N, prefer M*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", m, m, &rwork[iru], m, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, m, &work[il], &ldwrkl, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix WORK(IVT) Overwrite WORK(IVT) by the right singular vectors of L (CWorkspace: need N*N+3*N, prefer M*N+2*N+N*NB) (RWorkspace: 0) */ zlacp2_("F", m, m, &rwork[irvt], m, &work[ivt], &ldwkvt); i__2 = *lwork - nwork + 1; zunmbr_("P", "R", "C", m, m, m, &work[il], &ldwrkl, &work[ itaup], &work[ivt], &ldwkvt, &work[nwork], &i__2, & ierr); /* Multiply right singular vectors of L in WORK(IL) by Q in A, storing result in WORK(IL) and copying to A (CWorkspace: need 2*M*M, prefer M*M+M*N)) (RWorkspace: 0) */ i__2 = *n; i__1 = chunk; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Computing MIN */ i__3 = *n - i__ + 1; blk = min(i__3,chunk); zgemm_("N", "N", m, &blk, m, &c_b57, &work[ivt], m, &a[ i__ * a_dim1 + 1], lda, &c_b56, &work[il], & ldwrkl); zlacpy_("F", m, &blk, &work[il], &ldwrkl, &a[i__ * a_dim1 + 1], lda); /* L40: */ } } else if (wntqs) { /* Path 3t (N much larger than M, JOBZ='S') M right singular vectors to be computed in VT and M left singular vectors to be computed in U */ il = 1; /* WORK(IL) is M by M */ ldwrkl = *m; itau = il + ldwrkl * *m; nwork = itau + *m; /* Compute A=L*Q (CWorkspace: need 2*M, prefer M+M*NB) (RWorkspace: 0) */ i__1 = *lwork - nwork + 1; zgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); /* Copy L to WORK(IL), zeroing out above it */ zlacpy_("L", m, m, &a[a_offset], lda, &work[il], &ldwrkl); i__1 = *m - 1; i__2 = *m - 1; zlaset_("U", &i__1, &i__2, &c_b56, &c_b56, &work[il + ldwrkl], &ldwrkl); /* Generate Q in A (CWorkspace: need M*M+2*M, prefer M*M+M+M*NB) (RWorkspace: 0) */ i__1 = *lwork - nwork + 1; zunglq_(m, n, m, &a[a_offset], lda, &work[itau], &work[nwork], &i__1, &ierr); ie = 1; itauq = itau; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in WORK(IL) (CWorkspace: need M*M+3*M, prefer M*M+2*M+2*M*NB) (RWorkspace: need M) */ i__1 = *lwork - nwork + 1; zgebrd_(m, m, &work[il], &ldwrkl, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = ie + *m; irvt = iru + *m * *m; nrwork = irvt + *m * *m; dbdsdc_("U", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of L (CWorkspace: need M*M+3*M, prefer M*M+2*M+M*NB) (RWorkspace: 0) */ zlacp2_("F", m, m, &rwork[iru], m, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, m, &work[il], &ldwrkl, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by left singular vectors of L (CWorkspace: need M*M+3*M, prefer M*M+2*M+M*NB) (RWorkspace: 0) */ zlacp2_("F", m, m, &rwork[irvt], m, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zunmbr_("P", "R", "C", m, m, m, &work[il], &ldwrkl, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); /* Copy VT to WORK(IL), multiply right singular vectors of L in WORK(IL) by Q in A, storing result in VT (CWorkspace: need M*M) (RWorkspace: 0) */ zlacpy_("F", m, m, &vt[vt_offset], ldvt, &work[il], &ldwrkl); zgemm_("N", "N", m, n, m, &c_b57, &work[il], &ldwrkl, &a[ a_offset], lda, &c_b56, &vt[vt_offset], ldvt); } else if (wntqa) { /* Path 9t (N much larger than M, JOBZ='A') N right singular vectors to be computed in VT and M left singular vectors to be computed in U */ ivt = 1; /* WORK(IVT) is M by M */ ldwkvt = *m; itau = ivt + ldwkvt * *m; nwork = itau + *m; /* Compute A=L*Q, copying result to VT (CWorkspace: need 2*M, prefer M+M*NB) (RWorkspace: 0) */ i__1 = *lwork - nwork + 1; zgelqf_(m, n, &a[a_offset], lda, &work[itau], &work[nwork], & i__1, &ierr); zlacpy_("U", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); /* Generate Q in VT (CWorkspace: need M+N, prefer M+N*NB) (RWorkspace: 0) */ i__1 = *lwork - nwork + 1; zunglq_(n, n, m, &vt[vt_offset], ldvt, &work[itau], &work[ nwork], &i__1, &ierr); /* Produce L in A, zeroing out above it */ i__1 = *m - 1; i__2 = *m - 1; zlaset_("U", &i__1, &i__2, &c_b56, &c_b56, &a[(a_dim1 << 1) + 1], lda); ie = 1; itauq = itau; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize L in A (CWorkspace: need M*M+3*M, prefer M*M+2*M+2*M*NB) (RWorkspace: need M) */ i__1 = *lwork - nwork + 1; zgebrd_(m, m, &a[a_offset], lda, &s[1], &rwork[ie], &work[ itauq], &work[itaup], &work[nwork], &i__1, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ iru = ie + *m; irvt = iru + *m * *m; nrwork = irvt + *m * *m; dbdsdc_("U", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of L (CWorkspace: need 3*M, prefer 2*M+M*NB) (RWorkspace: 0) */ zlacp2_("F", m, m, &rwork[iru], m, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, m, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix WORK(IVT) Overwrite WORK(IVT) by right singular vectors of L (CWorkspace: need M*M+3*M, prefer M*M+2*M+M*NB) (RWorkspace: 0) */ zlacp2_("F", m, m, &rwork[irvt], m, &work[ivt], &ldwkvt); i__1 = *lwork - nwork + 1; zunmbr_("P", "R", "C", m, m, m, &a[a_offset], lda, &work[ itaup], &work[ivt], &ldwkvt, &work[nwork], &i__1, & ierr); /* Multiply right singular vectors of L in WORK(IVT) by Q in VT, storing result in A (CWorkspace: need M*M) (RWorkspace: 0) */ zgemm_("N", "N", m, n, m, &c_b57, &work[ivt], &ldwkvt, &vt[ vt_offset], ldvt, &c_b56, &a[a_offset], lda); /* Copy right singular vectors of A from A to VT */ zlacpy_("F", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); } } else if (*n >= mnthr2) { /* MNTHR2 <= N < MNTHR1 Path 5t (N much larger than M, but not as much as MNTHR1) Reduce to bidiagonal form without QR decomposition, use ZUNGBR and matrix multiplication to compute singular vectors */ ie = 1; nrwork = ie + *m; itauq = 1; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize A (CWorkspace: need 2*M+N, prefer 2*M+(M+N)*NB) (RWorkspace: M) */ i__1 = *lwork - nwork + 1; zgebrd_(m, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[itauq], &work[itaup], &work[nwork], &i__1, &ierr); if (wntqn) { /* Compute singular values only (Cworkspace: 0) (Rworkspace: need BDSPAN) */ dbdsdc_("L", "N", m, &s[1], &rwork[ie], dum, &c__1, dum, & c__1, dum, idum, &rwork[nrwork], &iwork[1], info); } else if (wntqo) { irvt = nrwork; iru = irvt + *m * *m; nrwork = iru + *m * *m; ivt = nwork; /* Copy A to U, generate Q (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: 0) */ zlacpy_("L", m, m, &a[a_offset], lda, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zungbr_("Q", m, m, n, &u[u_offset], ldu, &work[itauq], &work[ nwork], &i__1, &ierr); /* Generate P**H in A (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: 0) */ i__1 = *lwork - nwork + 1; zungbr_("P", m, n, m, &a[a_offset], lda, &work[itaup], &work[ nwork], &i__1, &ierr); ldwkvt = *m; if (*lwork >= *m * *n + *m * 3) { /* WORK( IVT ) is M by N */ nwork = ivt + ldwkvt * *n; chunk = *n; } else { /* WORK( IVT ) is M by CHUNK */ chunk = (*lwork - *m * 3) / *m; nwork = ivt + ldwkvt * chunk; } /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ dbdsdc_("L", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Multiply Q in U by real matrix RWORK(IRVT) storing the result in WORK(IVT), copying to U (Cworkspace: need 0) (Rworkspace: need 2*M*M) */ zlacrm_(m, m, &u[u_offset], ldu, &rwork[iru], m, &work[ivt], & ldwkvt, &rwork[nrwork]); zlacpy_("F", m, m, &work[ivt], &ldwkvt, &u[u_offset], ldu); /* Multiply RWORK(IRVT) by P**H in A, storing the result in WORK(IVT), copying to A (CWorkspace: need M*M, prefer M*N) (Rworkspace: need 2*M*M, prefer 2*M*N) */ nrwork = iru; i__1 = *n; i__2 = chunk; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = *n - i__ + 1; blk = min(i__3,chunk); zlarcm_(m, &blk, &rwork[irvt], m, &a[i__ * a_dim1 + 1], lda, &work[ivt], &ldwkvt, &rwork[nrwork]); zlacpy_("F", m, &blk, &work[ivt], &ldwkvt, &a[i__ * a_dim1 + 1], lda); /* L50: */ } } else if (wntqs) { /* Copy A to U, generate Q (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: 0) */ zlacpy_("L", m, m, &a[a_offset], lda, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zungbr_("Q", m, m, n, &u[u_offset], ldu, &work[itauq], &work[ nwork], &i__2, &ierr); /* Copy A to VT, generate P**H (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: 0) */ zlacpy_("U", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zungbr_("P", m, n, m, &vt[vt_offset], ldvt, &work[itaup], & work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ irvt = nrwork; iru = irvt + *m * *m; nrwork = iru + *m * *m; dbdsdc_("L", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Multiply Q in U by real matrix RWORK(IRU), storing the result in A, copying to U (CWorkspace: need 0) (Rworkspace: need 3*M*M) */ zlacrm_(m, m, &u[u_offset], ldu, &rwork[iru], m, &a[a_offset], lda, &rwork[nrwork]); zlacpy_("F", m, m, &a[a_offset], lda, &u[u_offset], ldu); /* Multiply real matrix RWORK(IRVT) by P**H in VT, storing the result in A, copying to VT (Cworkspace: need 0) (Rworkspace: need M*M+2*M*N) */ nrwork = iru; zlarcm_(m, n, &rwork[irvt], m, &vt[vt_offset], ldvt, &a[ a_offset], lda, &rwork[nrwork]); zlacpy_("F", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); } else { /* Copy A to U, generate Q (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: 0) */ zlacpy_("L", m, m, &a[a_offset], lda, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zungbr_("Q", m, m, n, &u[u_offset], ldu, &work[itauq], &work[ nwork], &i__2, &ierr); /* Copy A to VT, generate P**H (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: 0) */ zlacpy_("U", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); i__2 = *lwork - nwork + 1; zungbr_("P", n, n, m, &vt[vt_offset], ldvt, &work[itaup], & work[nwork], &i__2, &ierr); /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ irvt = nrwork; iru = irvt + *m * *m; nrwork = iru + *m * *m; dbdsdc_("L", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Multiply Q in U by real matrix RWORK(IRU), storing the result in A, copying to U (CWorkspace: need 0) (Rworkspace: need 3*M*M) */ zlacrm_(m, m, &u[u_offset], ldu, &rwork[iru], m, &a[a_offset], lda, &rwork[nrwork]); zlacpy_("F", m, m, &a[a_offset], lda, &u[u_offset], ldu); /* Multiply real matrix RWORK(IRVT) by P**H in VT, storing the result in A, copying to VT (Cworkspace: need 0) (Rworkspace: need M*M+2*M*N) */ zlarcm_(m, n, &rwork[irvt], m, &vt[vt_offset], ldvt, &a[ a_offset], lda, &rwork[nrwork]); zlacpy_("F", m, n, &a[a_offset], lda, &vt[vt_offset], ldvt); } } else { /* N .LT. MNTHR2 Path 6t (N greater than M, but not much larger) Reduce to bidiagonal form without LQ decomposition Use ZUNMBR to compute singular vectors */ ie = 1; nrwork = ie + *m; itauq = 1; itaup = itauq + *m; nwork = itaup + *m; /* Bidiagonalize A (CWorkspace: need 2*M+N, prefer 2*M+(M+N)*NB) (RWorkspace: M) */ i__2 = *lwork - nwork + 1; zgebrd_(m, n, &a[a_offset], lda, &s[1], &rwork[ie], &work[itauq], &work[itaup], &work[nwork], &i__2, &ierr); if (wntqn) { /* Compute singular values only (Cworkspace: 0) (Rworkspace: need BDSPAN) */ dbdsdc_("L", "N", m, &s[1], &rwork[ie], dum, &c__1, dum, & c__1, dum, idum, &rwork[nrwork], &iwork[1], info); } else if (wntqo) { ldwkvt = *m; ivt = nwork; if (*lwork >= *m * *n + *m * 3) { /* WORK( IVT ) is M by N */ zlaset_("F", m, n, &c_b56, &c_b56, &work[ivt], &ldwkvt); nwork = ivt + ldwkvt * *n; } else { /* WORK( IVT ) is M by CHUNK */ chunk = (*lwork - *m * 3) / *m; nwork = ivt + ldwkvt * chunk; } /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ irvt = nrwork; iru = irvt + *m * *m; nrwork = iru + *m * *m; dbdsdc_("L", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of A (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: need 0) */ zlacp2_("F", m, m, &rwork[iru], m, &u[u_offset], ldu); i__2 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__2, &ierr); if (*lwork >= *m * *n + *m * 3) { /* Copy real matrix RWORK(IRVT) to complex matrix WORK(IVT) Overwrite WORK(IVT) by right singular vectors of A, copying to A (Cworkspace: need M*N+2*M, prefer M*N+M+M*NB) (Rworkspace: need 0) */ zlacp2_("F", m, m, &rwork[irvt], m, &work[ivt], &ldwkvt); i__2 = *lwork - nwork + 1; zunmbr_("P", "R", "C", m, n, m, &a[a_offset], lda, &work[ itaup], &work[ivt], &ldwkvt, &work[nwork], &i__2, &ierr); zlacpy_("F", m, n, &work[ivt], &ldwkvt, &a[a_offset], lda); } else { /* Generate P**H in A (Cworkspace: need 2*M, prefer M+M*NB) (Rworkspace: need 0) */ i__2 = *lwork - nwork + 1; zungbr_("P", m, n, m, &a[a_offset], lda, &work[itaup], & work[nwork], &i__2, &ierr); /* Multiply Q in A by real matrix RWORK(IRU), storing the result in WORK(IU), copying to A (CWorkspace: need M*M, prefer M*N) (Rworkspace: need 3*M*M, prefer M*M+2*M*N) */ nrwork = iru; i__2 = *n; i__1 = chunk; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Computing MIN */ i__3 = *n - i__ + 1; blk = min(i__3,chunk); zlarcm_(m, &blk, &rwork[irvt], m, &a[i__ * a_dim1 + 1] , lda, &work[ivt], &ldwkvt, &rwork[nrwork]); zlacpy_("F", m, &blk, &work[ivt], &ldwkvt, &a[i__ * a_dim1 + 1], lda); /* L60: */ } } } else if (wntqs) { /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ irvt = nrwork; iru = irvt + *m * *m; nrwork = iru + *m * *m; dbdsdc_("L", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of A (CWorkspace: need 3*M, prefer 2*M+M*NB) (RWorkspace: M*M) */ zlacp2_("F", m, m, &rwork[iru], m, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of A (CWorkspace: need 3*M, prefer 2*M+M*NB) (RWorkspace: M*M) */ zlaset_("F", m, n, &c_b56, &c_b56, &vt[vt_offset], ldvt); zlacp2_("F", m, m, &rwork[irvt], m, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zunmbr_("P", "R", "C", m, n, m, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); } else { /* Perform bidiagonal SVD, computing left singular vectors of bidiagonal matrix in RWORK(IRU) and computing right singular vectors of bidiagonal matrix in RWORK(IRVT) (CWorkspace: need 0) (RWorkspace: need BDSPAC) */ irvt = nrwork; iru = irvt + *m * *m; nrwork = iru + *m * *m; dbdsdc_("L", "I", m, &s[1], &rwork[ie], &rwork[iru], m, & rwork[irvt], m, dum, idum, &rwork[nrwork], &iwork[1], info); /* Copy real matrix RWORK(IRU) to complex matrix U Overwrite U by left singular vectors of A (CWorkspace: need 3*M, prefer 2*M+M*NB) (RWorkspace: M*M) */ zlacp2_("F", m, m, &rwork[iru], m, &u[u_offset], ldu); i__1 = *lwork - nwork + 1; zunmbr_("Q", "L", "N", m, m, n, &a[a_offset], lda, &work[ itauq], &u[u_offset], ldu, &work[nwork], &i__1, &ierr); /* Set all of VT to identity matrix */ zlaset_("F", n, n, &c_b56, &c_b57, &vt[vt_offset], ldvt); /* Copy real matrix RWORK(IRVT) to complex matrix VT Overwrite VT by right singular vectors of A (CWorkspace: need 2*M+N, prefer 2*M+N*NB) (RWorkspace: M*M) */ zlacp2_("F", m, m, &rwork[irvt], m, &vt[vt_offset], ldvt); i__1 = *lwork - nwork + 1; zunmbr_("P", "R", "C", n, n, m, &a[a_offset], lda, &work[ itaup], &vt[vt_offset], ldvt, &work[nwork], &i__1, & ierr); } } } /* Undo scaling if necessary */ if (iscl == 1) { if (anrm > bignum) { dlascl_("G", &c__0, &c__0, &bignum, &anrm, &minmn, &c__1, &s[1], & minmn, &ierr); } if (*info != 0 && anrm > bignum) { i__1 = minmn - 1; dlascl_("G", &c__0, &c__0, &bignum, &anrm, &i__1, &c__1, &rwork[ ie], &minmn, &ierr); } if (anrm < smlnum) { dlascl_("G", &c__0, &c__0, &smlnum, &anrm, &minmn, &c__1, &s[1], & minmn, &ierr); } if (*info != 0 && anrm < smlnum) { i__1 = minmn - 1; dlascl_("G", &c__0, &c__0, &smlnum, &anrm, &i__1, &c__1, &rwork[ ie], &minmn, &ierr); } } /* Return optimal workspace in WORK(1) */ work[1].r = (doublereal) maxwrk, work[1].i = 0.; return 0; /* End of ZGESDD */ } /* zgesdd_ */ /* Subroutine */ int zgesv_(integer *n, integer *nrhs, doublecomplex *a, integer *lda, integer *ipiv, doublecomplex *b, integer *ldb, integer * info) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, i__1; /* Local variables */ extern /* Subroutine */ int xerbla_(char *, integer *), zgetrf_( integer *, integer *, doublecomplex *, integer *, integer *, integer *), zgetrs_(char *, integer *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK driver routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGESV computes the solution to a complex system of linear equations A * X = B, where A is an N-by-N matrix and X and B are N-by-NRHS matrices. The LU decomposition with partial pivoting and row interchanges is used to factor A as A = P * L * U, where P is a permutation matrix, L is unit lower triangular, and U is upper triangular. The factored form of A is then used to solve the system of equations A * X = B. Arguments ========= N (input) INTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0. NRHS (input) INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the N-by-N coefficient matrix A. On exit, the factors L and U from the factorization A = P*L*U; the unit diagonal elements of L are not stored. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). IPIV (output) INTEGER array, dimension (N) The pivot indices that define the permutation matrix P; row i of the matrix was interchanged with row IPIV(i). B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) On entry, the N-by-NRHS matrix of right hand side matrix B. On exit, if INFO = 0, the N-by-NRHS solution matrix X. LDB (input) INTEGER The leading dimension of the array B. LDB >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, U(i,i) is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --ipiv; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; /* Function Body */ *info = 0; if (*n < 0) { *info = -1; } else if (*nrhs < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } else if (*ldb < max(1,*n)) { *info = -7; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGESV ", &i__1); return 0; } /* Compute the LU factorization of A. */ zgetrf_(n, n, &a[a_offset], lda, &ipiv[1], info); if (*info == 0) { /* Solve the system A*X = B, overwriting B with X. */ zgetrs_("No transpose", n, nrhs, &a[a_offset], lda, &ipiv[1], &b[ b_offset], ldb, info); } return 0; /* End of ZGESV */ } /* zgesv_ */ /* Subroutine */ int zgetf2_(integer *m, integer *n, doublecomplex *a, integer *lda, integer *ipiv, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ double z_abs(doublecomplex *); void z_div(doublecomplex *, doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j, jp; static doublereal sfmin; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *), zgeru_(integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int xerbla_(char *, integer *); extern integer izamax_(integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGETF2 computes an LU factorization of a general m-by-n matrix A using partial pivoting with row interchanges. The factorization has the form A = P * L * U where P is a permutation matrix, L is lower triangular with unit diagonal elements (lower trapezoidal if m > n), and U is upper triangular (upper trapezoidal if m < n). This is the right-looking Level 2 BLAS version of the algorithm. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the m by n matrix to be factored. On exit, the factors L and U from the factorization A = P*L*U; the unit diagonal elements of L are not stored. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). IPIV (output) INTEGER array, dimension (min(M,N)) The pivot indices; for 1 <= i <= min(M,N), row i of the matrix was interchanged with row IPIV(i). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value > 0: if INFO = k, U(k,k) is exactly zero. The factorization has been completed, but the factor U is exactly singular, and division by zero will occur if it is used to solve a system of equations. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --ipiv; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGETF2", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } /* Compute machine safe minimum */ sfmin = SAFEMINIMUM; i__1 = min(*m,*n); for (j = 1; j <= i__1; ++j) { /* Find pivot and test for singularity. */ i__2 = *m - j + 1; jp = j - 1 + izamax_(&i__2, &a[j + j * a_dim1], &c__1); ipiv[j] = jp; i__2 = jp + j * a_dim1; if (a[i__2].r != 0. || a[i__2].i != 0.) { /* Apply the interchange to columns 1:N. */ if (jp != j) { zswap_(n, &a[j + a_dim1], lda, &a[jp + a_dim1], lda); } /* Compute elements J+1:M of J-th column. */ if (j < *m) { if (z_abs(&a[j + j * a_dim1]) >= sfmin) { i__2 = *m - j; z_div(&z__1, &c_b57, &a[j + j * a_dim1]); zscal_(&i__2, &z__1, &a[j + 1 + j * a_dim1], &c__1); } else { i__2 = *m - j; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = j + i__ + j * a_dim1; z_div(&z__1, &a[j + i__ + j * a_dim1], &a[j + j * a_dim1]); a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L20: */ } } } } else if (*info == 0) { *info = j; } if (j < min(*m,*n)) { /* Update trailing submatrix. */ i__2 = *m - j; i__3 = *n - j; z__1.r = -1., z__1.i = -0.; zgeru_(&i__2, &i__3, &z__1, &a[j + 1 + j * a_dim1], &c__1, &a[j + (j + 1) * a_dim1], lda, &a[j + 1 + (j + 1) * a_dim1], lda) ; } /* L10: */ } return 0; /* End of ZGETF2 */ } /* zgetf2_ */ /* Subroutine */ int zgetrf_(integer *m, integer *n, doublecomplex *a, integer *lda, integer *ipiv, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5; doublecomplex z__1; /* Local variables */ static integer i__, j, jb, nb, iinfo; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer * , doublecomplex *, integer *), zgetf2_(integer *, integer *, doublecomplex *, integer *, integer *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlaswp_(integer *, doublecomplex *, integer *, integer *, integer *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGETRF computes an LU factorization of a general M-by-N matrix A using partial pivoting with row interchanges. The factorization has the form A = P * L * U where P is a permutation matrix, L is lower triangular with unit diagonal elements (lower trapezoidal if m > n), and U is upper triangular (upper trapezoidal if m < n). This is the right-looking Level 3 BLAS version of the algorithm. Arguments ========= M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N matrix to be factored. On exit, the factors L and U from the factorization A = P*L*U; the unit diagonal elements of L are not stored. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). IPIV (output) INTEGER array, dimension (min(M,N)) The pivot indices; for 1 <= i <= min(M,N), row i of the matrix was interchanged with row IPIV(i). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, U(i,i) is exactly zero. The factorization has been completed, but the factor U is exactly singular, and division by zero will occur if it is used to solve a system of equations. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --ipiv; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*m)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGETRF", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } /* Determine the block size for this environment. */ nb = ilaenv_(&c__1, "ZGETRF", " ", m, n, &c_n1, &c_n1, (ftnlen)6, (ftnlen) 1); if (nb <= 1 || nb >= min(*m,*n)) { /* Use unblocked code. */ zgetf2_(m, n, &a[a_offset], lda, &ipiv[1], info); } else { /* Use blocked code. */ i__1 = min(*m,*n); i__2 = nb; for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Computing MIN */ i__3 = min(*m,*n) - j + 1; jb = min(i__3,nb); /* Factor diagonal and subdiagonal blocks and test for exact singularity. */ i__3 = *m - j + 1; zgetf2_(&i__3, &jb, &a[j + j * a_dim1], lda, &ipiv[j], &iinfo); /* Adjust INFO and the pivot indices. */ if (*info == 0 && iinfo > 0) { *info = iinfo + j - 1; } /* Computing MIN */ i__4 = *m, i__5 = j + jb - 1; i__3 = min(i__4,i__5); for (i__ = j; i__ <= i__3; ++i__) { ipiv[i__] = j - 1 + ipiv[i__]; /* L10: */ } /* Apply interchanges to columns 1:J-1. */ i__3 = j - 1; i__4 = j + jb - 1; zlaswp_(&i__3, &a[a_offset], lda, &j, &i__4, &ipiv[1], &c__1); if (j + jb <= *n) { /* Apply interchanges to columns J+JB:N. */ i__3 = *n - j - jb + 1; i__4 = j + jb - 1; zlaswp_(&i__3, &a[(j + jb) * a_dim1 + 1], lda, &j, &i__4, & ipiv[1], &c__1); /* Compute block row of U. */ i__3 = *n - j - jb + 1; ztrsm_("Left", "Lower", "No transpose", "Unit", &jb, &i__3, & c_b57, &a[j + j * a_dim1], lda, &a[j + (j + jb) * a_dim1], lda); if (j + jb <= *m) { /* Update trailing submatrix. */ i__3 = *m - j - jb + 1; i__4 = *n - j - jb + 1; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "No transpose", &i__3, &i__4, &jb, &z__1, &a[j + jb + j * a_dim1], lda, &a[j + (j + jb) * a_dim1], lda, &c_b57, &a[j + jb + (j + jb) * a_dim1], lda); } } /* L20: */ } } return 0; /* End of ZGETRF */ } /* zgetrf_ */ /* Subroutine */ int zgetrs_(char *trans, integer *n, integer *nrhs, doublecomplex *a, integer *lda, integer *ipiv, doublecomplex *b, integer *ldb, integer *info) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, i__1; /* Local variables */ extern logical lsame_(char *, char *); extern /* Subroutine */ int ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); static logical notran; extern /* Subroutine */ int zlaswp_(integer *, doublecomplex *, integer *, integer *, integer *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZGETRS solves a system of linear equations A * X = B, A**T * X = B, or A**H * X = B with a general N-by-N matrix A using the LU factorization computed by ZGETRF. Arguments ========= TRANS (input) CHARACTER*1 Specifies the form of the system of equations: = 'N': A * X = B (No transpose) = 'T': A**T * X = B (Transpose) = 'C': A**H * X = B (Conjugate transpose) N (input) INTEGER The order of the matrix A. N >= 0. NRHS (input) INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) The factors L and U from the factorization A = P*L*U as computed by ZGETRF. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). IPIV (input) INTEGER array, dimension (N) The pivot indices from ZGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i). B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) On entry, the right hand side matrix B. On exit, the solution matrix X. LDB (input) INTEGER The leading dimension of the array B. LDB >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --ipiv; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; /* Function Body */ *info = 0; notran = lsame_(trans, "N"); if (! notran && ! lsame_(trans, "T") && ! lsame_( trans, "C")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*nrhs < 0) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } else if (*ldb < max(1,*n)) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZGETRS", &i__1); return 0; } /* Quick return if possible */ if (*n == 0 || *nrhs == 0) { return 0; } if (notran) { /* Solve A * X = B. Apply row interchanges to the right hand sides. */ zlaswp_(nrhs, &b[b_offset], ldb, &c__1, n, &ipiv[1], &c__1); /* Solve L*X = B, overwriting B with X. */ ztrsm_("Left", "Lower", "No transpose", "Unit", n, nrhs, &c_b57, &a[ a_offset], lda, &b[b_offset], ldb); /* Solve U*X = B, overwriting B with X. */ ztrsm_("Left", "Upper", "No transpose", "Non-unit", n, nrhs, &c_b57, & a[a_offset], lda, &b[b_offset], ldb); } else { /* Solve A**T * X = B or A**H * X = B. Solve U'*X = B, overwriting B with X. */ ztrsm_("Left", "Upper", trans, "Non-unit", n, nrhs, &c_b57, &a[ a_offset], lda, &b[b_offset], ldb); /* Solve L'*X = B, overwriting B with X. */ ztrsm_("Left", "Lower", trans, "Unit", n, nrhs, &c_b57, &a[a_offset], lda, &b[b_offset], ldb); /* Apply row interchanges to the solution vectors. */ zlaswp_(nrhs, &b[b_offset], ldb, &c__1, n, &ipiv[1], &c_n1); } return 0; /* End of ZGETRS */ } /* zgetrs_ */ /* Subroutine */ int zheevd_(char *jobz, char *uplo, integer *n, doublecomplex *a, integer *lda, doublereal *w, doublecomplex *work, integer *lwork, doublereal *rwork, integer *lrwork, integer *iwork, integer *liwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; doublereal d__1; /* Builtin functions */ double sqrt(doublereal); /* Local variables */ static doublereal eps; static integer inde; static doublereal anrm; static integer imax; static doublereal rmin, rmax; static integer lopt; extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, integer *); static doublereal sigma; extern logical lsame_(char *, char *); static integer iinfo, lwmin, liopt; static logical lower; static integer llrwk, lropt; static logical wantz; static integer indwk2, llwrk2; static integer iscale; static doublereal safmin; extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int xerbla_(char *, integer *); static doublereal bignum; extern doublereal zlanhe_(char *, char *, integer *, doublecomplex *, integer *, doublereal *); static integer indtau; extern /* Subroutine */ int dsterf_(integer *, doublereal *, doublereal *, integer *), zlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublecomplex *, integer *, integer *), zstedc_(char *, integer *, doublereal *, doublereal *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, integer *, integer *, integer *, integer *); static integer indrwk, indwrk, liwmin; extern /* Subroutine */ int zhetrd_(char *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, doublecomplex *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer lrwmin, llwork; static doublereal smlnum; static logical lquery; extern /* Subroutine */ int zunmtr_(char *, char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK driver routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZHEEVD computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= JOBZ (input) CHARACTER*1 = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA, N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A. On exit, if JOBZ = 'V', then if INFO = 0, A contains the orthonormal eigenvectors of the matrix A. If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') or the upper triangle (if UPLO='U') of A, including the diagonal, is destroyed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). W (output) DOUBLE PRECISION array, dimension (N) If INFO = 0, the eigenvalues in ascending order. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The length of the array WORK. If N <= 1, LWORK must be at least 1. If JOBZ = 'N' and N > 1, LWORK must be at least N + 1. If JOBZ = 'V' and N > 1, LWORK must be at least 2*N + N**2. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. RWORK (workspace/output) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK. LRWORK (input) INTEGER The dimension of the array RWORK. If N <= 1, LRWORK must be at least 1. If JOBZ = 'N' and N > 1, LRWORK must be at least N. If JOBZ = 'V' and N > 1, LRWORK must be at least 1 + 5*N + 2*N**2. If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. IWORK (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. LIWORK (input) INTEGER The dimension of the array IWORK. If N <= 1, LIWORK must be at least 1. If JOBZ = 'N' and N > 1, LIWORK must be at least 1. If JOBZ = 'V' and N > 1, LIWORK must be at least 3 + 5*N. If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i and JOBZ = 'N', then the algorithm failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not converge to zero; if INFO = i and JOBZ = 'V', then the algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details =============== Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA Modified description of INFO. Sven, 16 Feb 05. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --w; --work; --rwork; --iwork; /* Function Body */ wantz = lsame_(jobz, "V"); lower = lsame_(uplo, "L"); lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1; *info = 0; if (! (wantz || lsame_(jobz, "N"))) { *info = -1; } else if (! (lower || lsame_(uplo, "U"))) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } if (*info == 0) { if (*n <= 1) { lwmin = 1; lrwmin = 1; liwmin = 1; lopt = lwmin; lropt = lrwmin; liopt = liwmin; } else { if (wantz) { lwmin = (*n << 1) + *n * *n; /* Computing 2nd power */ i__1 = *n; lrwmin = *n * 5 + 1 + (i__1 * i__1 << 1); liwmin = *n * 5 + 3; } else { lwmin = *n + 1; lrwmin = *n; liwmin = 1; } /* Computing MAX */ i__1 = lwmin, i__2 = *n + ilaenv_(&c__1, "ZHETRD", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); lopt = max(i__1,i__2); lropt = lrwmin; liopt = liwmin; } work[1].r = (doublereal) lopt, work[1].i = 0.; rwork[1] = (doublereal) lropt; iwork[1] = liopt; if (*lwork < lwmin && ! lquery) { *info = -8; } else if (*lrwork < lrwmin && ! lquery) { *info = -10; } else if (*liwork < liwmin && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("ZHEEVD", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } if (*n == 1) { i__1 = a_dim1 + 1; w[1] = a[i__1].r; if (wantz) { i__1 = a_dim1 + 1; a[i__1].r = 1., a[i__1].i = 0.; } return 0; } /* Get machine constants. */ safmin = SAFEMINIMUM; eps = PRECISION; smlnum = safmin / eps; bignum = 1. / smlnum; rmin = sqrt(smlnum); rmax = sqrt(bignum); /* Scale matrix to allowable range, if necessary. */ anrm = zlanhe_("M", uplo, n, &a[a_offset], lda, &rwork[1]); iscale = 0; if (anrm > 0. && anrm < rmin) { iscale = 1; sigma = rmin / anrm; } else if (anrm > rmax) { iscale = 1; sigma = rmax / anrm; } if (iscale == 1) { zlascl_(uplo, &c__0, &c__0, &c_b1034, &sigma, n, n, &a[a_offset], lda, info); } /* Call ZHETRD to reduce Hermitian matrix to tridiagonal form. */ inde = 1; indtau = 1; indwrk = indtau + *n; indrwk = inde + *n; indwk2 = indwrk + *n * *n; llwork = *lwork - indwrk + 1; llwrk2 = *lwork - indwk2 + 1; llrwk = *lrwork - indrwk + 1; zhetrd_(uplo, n, &a[a_offset], lda, &w[1], &rwork[inde], &work[indtau], & work[indwrk], &llwork, &iinfo); /* For eigenvalues only, call DSTERF. For eigenvectors, first call ZSTEDC to generate the eigenvector matrix, WORK(INDWRK), of the tridiagonal matrix, then call ZUNMTR to multiply it to the Householder transformations represented as Householder vectors in A. */ if (! wantz) { dsterf_(n, &w[1], &rwork[inde], info); } else { zstedc_("I", n, &w[1], &rwork[inde], &work[indwrk], n, &work[indwk2], &llwrk2, &rwork[indrwk], &llrwk, &iwork[1], liwork, info); zunmtr_("L", uplo, "N", n, n, &a[a_offset], lda, &work[indtau], &work[ indwrk], n, &work[indwk2], &llwrk2, &iinfo); zlacpy_("A", n, n, &work[indwrk], n, &a[a_offset], lda); } /* If matrix was scaled, then rescale eigenvalues appropriately. */ if (iscale == 1) { if (*info == 0) { imax = *n; } else { imax = *info - 1; } d__1 = 1. / sigma; dscal_(&imax, &d__1, &w[1], &c__1); } work[1].r = (doublereal) lopt, work[1].i = 0.; rwork[1] = (doublereal) lropt; iwork[1] = liopt; return 0; /* End of ZHEEVD */ } /* zheevd_ */ /* Subroutine */ int zhetd2_(char *uplo, integer *n, doublecomplex *a, integer *lda, doublereal *d__, doublereal *e, doublecomplex *tau, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublereal d__1; doublecomplex z__1, z__2, z__3, z__4; /* Local variables */ static integer i__; static doublecomplex taui; extern /* Subroutine */ int zher2_(char *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static doublecomplex alpha; extern logical lsame_(char *, char *); extern /* Double Complex */ VOID zdotc_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int zhemv_(char *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static logical upper; extern /* Subroutine */ int zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_( char *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZHETD2 reduces a complex Hermitian matrix A to real symmetric tridiagonal form T by a unitary similarity transformation: Q' * A * Q = T. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the upper or lower triangular part of the Hermitian matrix A is stored: = 'U': Upper triangular = 'L': Lower triangular N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading n-by-n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n-by-n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if UPLO = 'U', the diagonal and first superdiagonal of A are overwritten by the corresponding elements of the tridiagonal matrix T, and the elements above the first superdiagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors; if UPLO = 'L', the diagonal and first subdiagonal of A are over- written by the corresponding elements of the tridiagonal matrix T, and the elements below the first subdiagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). D (output) DOUBLE PRECISION array, dimension (N) The diagonal elements of the tridiagonal matrix T: D(i) = A(i,i). E (output) DOUBLE PRECISION array, dimension (N-1) The off-diagonal elements of the tridiagonal matrix T: E(i) = A(i,i+1) if UPLO = 'U', E(i) = A(i+1,i) if UPLO = 'L'. TAU (output) COMPLEX*16 array, dimension (N-1) The scalar factors of the elementary reflectors (see Further Details). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== If UPLO = 'U', the matrix Q is represented as a product of elementary reflectors Q = H(n-1) . . . H(2) H(1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(i+1:n) = 0 and v(i) = 1; v(1:i-1) is stored on exit in A(1:i-1,i+1), and tau in TAU(i). If UPLO = 'L', the matrix Q is represented as a product of elementary reflectors Q = H(1) H(2) . . . H(n-1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i) = 0 and v(i+1) = 1; v(i+2:n) is stored on exit in A(i+2:n,i), and tau in TAU(i). The contents of A on exit are illustrated by the following examples with n = 5: if UPLO = 'U': if UPLO = 'L': ( d e v2 v3 v4 ) ( d ) ( d e v3 v4 ) ( e d ) ( d e v4 ) ( v1 e d ) ( d e ) ( v1 v2 e d ) ( d ) ( v1 v2 v3 e d ) where d and e denote diagonal and off-diagonal elements of T, and vi denotes an element of the vector defining H(i). ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --d__; --e; --tau; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZHETD2", &i__1); return 0; } /* Quick return if possible */ if (*n <= 0) { return 0; } if (upper) { /* Reduce the upper triangle of A */ i__1 = *n + *n * a_dim1; i__2 = *n + *n * a_dim1; d__1 = a[i__2].r; a[i__1].r = d__1, a[i__1].i = 0.; for (i__ = *n - 1; i__ >= 1; --i__) { /* Generate elementary reflector H(i) = I - tau * v * v' to annihilate A(1:i-1,i+1) */ i__1 = i__ + (i__ + 1) * a_dim1; alpha.r = a[i__1].r, alpha.i = a[i__1].i; zlarfg_(&i__, &alpha, &a[(i__ + 1) * a_dim1 + 1], &c__1, &taui); i__1 = i__; e[i__1] = alpha.r; if (taui.r != 0. || taui.i != 0.) { /* Apply H(i) from both sides to A(1:i,1:i) */ i__1 = i__ + (i__ + 1) * a_dim1; a[i__1].r = 1., a[i__1].i = 0.; /* Compute x := tau * A * v storing x in TAU(1:i) */ zhemv_(uplo, &i__, &taui, &a[a_offset], lda, &a[(i__ + 1) * a_dim1 + 1], &c__1, &c_b56, &tau[1], &c__1) ; /* Compute w := x - 1/2 * tau * (x'*v) * v */ z__3.r = -.5, z__3.i = -0.; z__2.r = z__3.r * taui.r - z__3.i * taui.i, z__2.i = z__3.r * taui.i + z__3.i * taui.r; zdotc_(&z__4, &i__, &tau[1], &c__1, &a[(i__ + 1) * a_dim1 + 1] , &c__1); z__1.r = z__2.r * z__4.r - z__2.i * z__4.i, z__1.i = z__2.r * z__4.i + z__2.i * z__4.r; alpha.r = z__1.r, alpha.i = z__1.i; zaxpy_(&i__, &alpha, &a[(i__ + 1) * a_dim1 + 1], &c__1, &tau[ 1], &c__1); /* Apply the transformation as a rank-2 update: A := A - v * w' - w * v' */ z__1.r = -1., z__1.i = -0.; zher2_(uplo, &i__, &z__1, &a[(i__ + 1) * a_dim1 + 1], &c__1, & tau[1], &c__1, &a[a_offset], lda); } else { i__1 = i__ + i__ * a_dim1; i__2 = i__ + i__ * a_dim1; d__1 = a[i__2].r; a[i__1].r = d__1, a[i__1].i = 0.; } i__1 = i__ + (i__ + 1) * a_dim1; i__2 = i__; a[i__1].r = e[i__2], a[i__1].i = 0.; i__1 = i__ + 1; i__2 = i__ + 1 + (i__ + 1) * a_dim1; d__[i__1] = a[i__2].r; i__1 = i__; tau[i__1].r = taui.r, tau[i__1].i = taui.i; /* L10: */ } i__1 = a_dim1 + 1; d__[1] = a[i__1].r; } else { /* Reduce the lower triangle of A */ i__1 = a_dim1 + 1; i__2 = a_dim1 + 1; d__1 = a[i__2].r; a[i__1].r = d__1, a[i__1].i = 0.; i__1 = *n - 1; for (i__ = 1; i__ <= i__1; ++i__) { /* Generate elementary reflector H(i) = I - tau * v * v' to annihilate A(i+2:n,i) */ i__2 = i__ + 1 + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[min(i__3,*n) + i__ * a_dim1], &c__1, & taui); i__2 = i__; e[i__2] = alpha.r; if (taui.r != 0. || taui.i != 0.) { /* Apply H(i) from both sides to A(i+1:n,i+1:n) */ i__2 = i__ + 1 + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute x := tau * A * v storing y in TAU(i:n-1) */ i__2 = *n - i__; zhemv_(uplo, &i__2, &taui, &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &a[i__ + 1 + i__ * a_dim1], &c__1, &c_b56, &tau[ i__], &c__1); /* Compute w := x - 1/2 * tau * (x'*v) * v */ z__3.r = -.5, z__3.i = -0.; z__2.r = z__3.r * taui.r - z__3.i * taui.i, z__2.i = z__3.r * taui.i + z__3.i * taui.r; i__2 = *n - i__; zdotc_(&z__4, &i__2, &tau[i__], &c__1, &a[i__ + 1 + i__ * a_dim1], &c__1); z__1.r = z__2.r * z__4.r - z__2.i * z__4.i, z__1.i = z__2.r * z__4.i + z__2.i * z__4.r; alpha.r = z__1.r, alpha.i = z__1.i; i__2 = *n - i__; zaxpy_(&i__2, &alpha, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[ i__], &c__1); /* Apply the transformation as a rank-2 update: A := A - v * w' - w * v' */ i__2 = *n - i__; z__1.r = -1., z__1.i = -0.; zher2_(uplo, &i__2, &z__1, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[i__], &c__1, &a[i__ + 1 + (i__ + 1) * a_dim1], lda); } else { i__2 = i__ + 1 + (i__ + 1) * a_dim1; i__3 = i__ + 1 + (i__ + 1) * a_dim1; d__1 = a[i__3].r; a[i__2].r = d__1, a[i__2].i = 0.; } i__2 = i__ + 1 + i__ * a_dim1; i__3 = i__; a[i__2].r = e[i__3], a[i__2].i = 0.; i__2 = i__; i__3 = i__ + i__ * a_dim1; d__[i__2] = a[i__3].r; i__2 = i__; tau[i__2].r = taui.r, tau[i__2].i = taui.i; /* L20: */ } i__1 = *n; i__2 = *n + *n * a_dim1; d__[i__1] = a[i__2].r; } return 0; /* End of ZHETD2 */ } /* zhetd2_ */ /* Subroutine */ int zhetrd_(char *uplo, integer *n, doublecomplex *a, integer *lda, doublereal *d__, doublereal *e, doublecomplex *tau, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5; doublecomplex z__1; /* Local variables */ static integer i__, j, nb, kk, nx, iws; extern logical lsame_(char *, char *); static integer nbmin, iinfo; static logical upper; extern /* Subroutine */ int zhetd2_(char *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, doublecomplex *, integer *), zher2k_(char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, doublecomplex *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlatrd_(char *, integer *, integer *, doublecomplex *, integer *, doublereal *, doublecomplex *, doublecomplex *, integer *); static integer ldwork, lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZHETRD reduces a complex Hermitian matrix A to real symmetric tridiagonal form T by a unitary similarity transformation: Q**H * A * Q = T. Arguments ========= UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if UPLO = 'U', the diagonal and first superdiagonal of A are overwritten by the corresponding elements of the tridiagonal matrix T, and the elements above the first superdiagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors; if UPLO = 'L', the diagonal and first subdiagonal of A are over- written by the corresponding elements of the tridiagonal matrix T, and the elements below the first subdiagonal, with the array TAU, represent the unitary matrix Q as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). D (output) DOUBLE PRECISION array, dimension (N) The diagonal elements of the tridiagonal matrix T: D(i) = A(i,i). E (output) DOUBLE PRECISION array, dimension (N-1) The off-diagonal elements of the tridiagonal matrix T: E(i) = A(i,i+1) if UPLO = 'U', E(i) = A(i+1,i) if UPLO = 'L'. TAU (output) COMPLEX*16 array, dimension (N-1) The scalar factors of the elementary reflectors (see Further Details). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= 1. For optimum performance LWORK >= N*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== If UPLO = 'U', the matrix Q is represented as a product of elementary reflectors Q = H(n-1) . . . H(2) H(1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(i+1:n) = 0 and v(i) = 1; v(1:i-1) is stored on exit in A(1:i-1,i+1), and tau in TAU(i). If UPLO = 'L', the matrix Q is represented as a product of elementary reflectors Q = H(1) H(2) . . . H(n-1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i) = 0 and v(i+1) = 1; v(i+2:n) is stored on exit in A(i+2:n,i), and tau in TAU(i). The contents of A on exit are illustrated by the following examples with n = 5: if UPLO = 'U': if UPLO = 'L': ( d e v2 v3 v4 ) ( d ) ( d e v3 v4 ) ( e d ) ( d e v4 ) ( v1 e d ) ( d e ) ( v1 v2 e d ) ( d ) ( v1 v2 v3 e d ) where d and e denote diagonal and off-diagonal elements of T, and vi denotes an element of the vector defining H(i). ===================================================================== Test the input parameters */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --d__; --e; --tau; --work; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); lquery = *lwork == -1; if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } else if (*lwork < 1 && ! lquery) { *info = -9; } if (*info == 0) { /* Determine the block size. */ nb = ilaenv_(&c__1, "ZHETRD", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); lwkopt = *n * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__1 = -(*info); xerbla_("ZHETRD", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*n == 0) { work[1].r = 1., work[1].i = 0.; return 0; } nx = *n; iws = 1; if (nb > 1 && nb < *n) { /* Determine when to cross over from blocked to unblocked code (last block is always handled by unblocked code). Computing MAX */ i__1 = nb, i__2 = ilaenv_(&c__3, "ZHETRD", uplo, n, &c_n1, &c_n1, & c_n1, (ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); if (nx < *n) { /* Determine if workspace is large enough for blocked code. */ ldwork = *n; iws = ldwork * nb; if (*lwork < iws) { /* Not enough workspace to use optimal NB: determine the minimum value of NB, and reduce NB or force use of unblocked code by setting NX = N. Computing MAX */ i__1 = *lwork / ldwork; nb = max(i__1,1); nbmin = ilaenv_(&c__2, "ZHETRD", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (ftnlen)1); if (nb < nbmin) { nx = *n; } } } else { nx = *n; } } else { nb = 1; } if (upper) { /* Reduce the upper triangle of A. Columns 1:kk are handled by the unblocked method. */ kk = *n - (*n - nx + nb - 1) / nb * nb; i__1 = kk + 1; i__2 = -nb; for (i__ = *n - nb + 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Reduce columns i:i+nb-1 to tridiagonal form and form the matrix W which is needed to update the unreduced part of the matrix */ i__3 = i__ + nb - 1; zlatrd_(uplo, &i__3, &nb, &a[a_offset], lda, &e[1], &tau[1], & work[1], &ldwork); /* Update the unreduced submatrix A(1:i-1,1:i-1), using an update of the form: A := A - V*W' - W*V' */ i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zher2k_(uplo, "No transpose", &i__3, &nb, &z__1, &a[i__ * a_dim1 + 1], lda, &work[1], &ldwork, &c_b1034, &a[a_offset], lda); /* Copy superdiagonal elements back into A, and diagonal elements into D */ i__3 = i__ + nb - 1; for (j = i__; j <= i__3; ++j) { i__4 = j - 1 + j * a_dim1; i__5 = j - 1; a[i__4].r = e[i__5], a[i__4].i = 0.; i__4 = j; i__5 = j + j * a_dim1; d__[i__4] = a[i__5].r; /* L10: */ } /* L20: */ } /* Use unblocked code to reduce the last or only block */ zhetd2_(uplo, &kk, &a[a_offset], lda, &d__[1], &e[1], &tau[1], &iinfo); } else { /* Reduce the lower triangle of A */ i__2 = *n - nx; i__1 = nb; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Reduce columns i:i+nb-1 to tridiagonal form and form the matrix W which is needed to update the unreduced part of the matrix */ i__3 = *n - i__ + 1; zlatrd_(uplo, &i__3, &nb, &a[i__ + i__ * a_dim1], lda, &e[i__], & tau[i__], &work[1], &ldwork); /* Update the unreduced submatrix A(i+nb:n,i+nb:n), using an update of the form: A := A - V*W' - W*V' */ i__3 = *n - i__ - nb + 1; z__1.r = -1., z__1.i = -0.; zher2k_(uplo, "No transpose", &i__3, &nb, &z__1, &a[i__ + nb + i__ * a_dim1], lda, &work[nb + 1], &ldwork, &c_b1034, &a[ i__ + nb + (i__ + nb) * a_dim1], lda); /* Copy subdiagonal elements back into A, and diagonal elements into D */ i__3 = i__ + nb - 1; for (j = i__; j <= i__3; ++j) { i__4 = j + 1 + j * a_dim1; i__5 = j; a[i__4].r = e[i__5], a[i__4].i = 0.; i__4 = j; i__5 = j + j * a_dim1; d__[i__4] = a[i__5].r; /* L30: */ } /* L40: */ } /* Use unblocked code to reduce the last or only block */ i__1 = *n - i__ + 1; zhetd2_(uplo, &i__1, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[i__], &tau[i__], &iinfo); } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZHETRD */ } /* zhetrd_ */ /* Subroutine */ int zhseqr_(char *job, char *compz, integer *n, integer *ilo, integer *ihi, doublecomplex *h__, integer *ldh, doublecomplex *w, doublecomplex *z__, integer *ldz, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3[2]; doublereal d__1, d__2, d__3; doublecomplex z__1; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static doublecomplex hl[2401] /* was [49][49] */; static integer kbot, nmin; extern logical lsame_(char *, char *); static logical initz; static doublecomplex workl[49]; static logical wantt, wantz; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaqr0_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *), xerbla_(char *, integer * ); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlahqr_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static logical lquery; /* -- LAPACK computational routine (version 3.2.2) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. June 2010 Purpose ======= ZHSEQR computes the eigenvalues of a Hessenberg matrix H and, optionally, the matrices T and Z from the Schur decomposition H = Z T Z**H, where T is an upper triangular matrix (the Schur form), and Z is the unitary matrix of Schur vectors. Optionally Z may be postmultiplied into an input unitary matrix Q so that this routine can give the Schur factorization of a matrix A which has been reduced to the Hessenberg form H by the unitary matrix Q: A = Q*H*Q**H = (QZ)*H*(QZ)**H. Arguments ========= JOB (input) CHARACTER*1 = 'E': compute eigenvalues only; = 'S': compute eigenvalues and the Schur form T. COMPZ (input) CHARACTER*1 = 'N': no Schur vectors are computed; = 'I': Z is initialized to the unit matrix and the matrix Z of Schur vectors of H is returned; = 'V': Z must contain an unitary matrix Q on entry, and the product Q*Z is returned. N (input) INTEGER The order of the matrix H. N .GE. 0. ILO (input) INTEGER IHI (input) INTEGER It is assumed that H is already upper triangular in rows and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally set by a previous call to ZGEBAL, and then passed to ZGEHRD when the matrix output by ZGEBAL is reduced to Hessenberg form. Otherwise ILO and IHI should be set to 1 and N respectively. If N.GT.0, then 1.LE.ILO.LE.IHI.LE.N. If N = 0, then ILO = 1 and IHI = 0. H (input/output) COMPLEX*16 array, dimension (LDH,N) On entry, the upper Hessenberg matrix H. On exit, if INFO = 0 and JOB = 'S', H contains the upper triangular matrix T from the Schur decomposition (the Schur form). If INFO = 0 and JOB = 'E', the contents of H are unspecified on exit. (The output value of H when INFO.GT.0 is given under the description of INFO below.) Unlike earlier versions of ZHSEQR, this subroutine may explicitly H(i,j) = 0 for i.GT.j and j = 1, 2, ... ILO-1 or j = IHI+1, IHI+2, ... N. LDH (input) INTEGER The leading dimension of the array H. LDH .GE. max(1,N). W (output) COMPLEX*16 array, dimension (N) The computed eigenvalues. If JOB = 'S', the eigenvalues are stored in the same order as on the diagonal of the Schur form returned in H, with W(i) = H(i,i). Z (input/output) COMPLEX*16 array, dimension (LDZ,N) If COMPZ = 'N', Z is not referenced. If COMPZ = 'I', on entry Z need not be set and on exit, if INFO = 0, Z contains the unitary matrix Z of the Schur vectors of H. If COMPZ = 'V', on entry Z must contain an N-by-N matrix Q, which is assumed to be equal to the unit matrix except for the submatrix Z(ILO:IHI,ILO:IHI). On exit, if INFO = 0, Z contains Q*Z. Normally Q is the unitary matrix generated by ZUNGHR after the call to ZGEHRD which formed the Hessenberg matrix H. (The output value of Z when INFO.GT.0 is given under the description of INFO below.) LDZ (input) INTEGER The leading dimension of the array Z. if COMPZ = 'I' or COMPZ = 'V', then LDZ.GE.MAX(1,N). Otherwize, LDZ.GE.1. WORK (workspace/output) COMPLEX*16 array, dimension (LWORK) On exit, if INFO = 0, WORK(1) returns an estimate of the optimal value for LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK .GE. max(1,N) is sufficient and delivers very good and sometimes optimal performance. However, LWORK as large as 11*N may be required for optimal performance. A workspace query is recommended to determine the optimal workspace size. If LWORK = -1, then ZHSEQR does a workspace query. In this case, ZHSEQR checks the input parameters and estimates the optimal workspace size for the given values of N, ILO and IHI. The estimate is returned in WORK(1). No error message related to LWORK is issued by XERBLA. Neither H nor Z are accessed. INFO (output) INTEGER = 0: successful exit .LT. 0: if INFO = -i, the i-th argument had an illegal value .GT. 0: if INFO = i, ZHSEQR failed to compute all of the eigenvalues. Elements 1:ilo-1 and i+1:n of WR and WI contain those eigenvalues which have been successfully computed. (Failures are rare.) If INFO .GT. 0 and JOB = 'E', then on exit, the remaining unconverged eigenvalues are the eigen- values of the upper Hessenberg matrix rows and columns ILO through INFO of the final, output value of H. If INFO .GT. 0 and JOB = 'S', then on exit (*) (initial value of H)*U = U*(final value of H) where U is a unitary matrix. The final value of H is upper Hessenberg and triangular in rows and columns INFO+1 through IHI. If INFO .GT. 0 and COMPZ = 'V', then on exit (final value of Z) = (initial value of Z)*U where U is the unitary matrix in (*) (regard- less of the value of JOB.) If INFO .GT. 0 and COMPZ = 'I', then on exit (final value of Z) = U where U is the unitary matrix in (*) (regard- less of the value of JOB.) If INFO .GT. 0 and COMPZ = 'N', then Z is not accessed. ================================================================ Default values supplied by ILAENV(ISPEC,'ZHSEQR',JOB(:1)//COMPZ(:1),N,ILO,IHI,LWORK). It is suggested that these defaults be adjusted in order to attain best performance in each particular computational environment. ISPEC=12: The ZLAHQR vs ZLAQR0 crossover point. Default: 75. (Must be at least 11.) ISPEC=13: Recommended deflation window size. This depends on ILO, IHI and NS. NS is the number of simultaneous shifts returned by ILAENV(ISPEC=15). (See ISPEC=15 below.) The default for (IHI-ILO+1).LE.500 is NS. The default for (IHI-ILO+1).GT.500 is 3*NS/2. ISPEC=14: Nibble crossover point. (See IPARMQ for details.) Default: 14% of deflation window size. ISPEC=15: Number of simultaneous shifts in a multishift QR iteration. If IHI-ILO+1 is ... greater than ...but less ... the or equal to ... than default is 1 30 NS = 2(+) 30 60 NS = 4(+) 60 150 NS = 10(+) 150 590 NS = ** 590 3000 NS = 64 3000 6000 NS = 128 6000 infinity NS = 256 (+) By default some or all matrices of this order are passed to the implicit double shift routine ZLAHQR and this parameter is ignored. See ISPEC=12 above and comments in IPARMQ for details. (**) The asterisks (**) indicate an ad-hoc function of N increasing from 10 to 64. ISPEC=16: Select structured matrix multiply. If the number of simultaneous shifts (specified by ISPEC=15) is less than 14, then the default for ISPEC=16 is 0. Otherwise the default for ISPEC=16 is 2. ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ References: K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 Performance, SIAM Journal of Matrix Analysis, volume 23, pages 929--947, 2002. K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part II: Aggressive Early Deflation, SIAM Journal of Matrix Analysis, volume 23, pages 948--973, 2002. ================================================================ ==== Matrices of order NTINY or smaller must be processed by . ZLAHQR because of insufficient subdiagonal scratch space. . (This is a hard limit.) ==== ==== NL allocates some local workspace to help small matrices . through a rare ZLAHQR failure. NL .GT. NTINY = 11 is . required and NL .LE. NMIN = ILAENV(ISPEC=12,...) is recom- . mended. (The default value of NMIN is 75.) Using NL = 49 . allows up to six simultaneous shifts and a 16-by-16 . deflation window. ==== ==== Decode and check the input parameters. ==== */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; --w; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --work; /* Function Body */ wantt = lsame_(job, "S"); initz = lsame_(compz, "I"); wantz = initz || lsame_(compz, "V"); d__1 = (doublereal) max(1,*n); z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; lquery = *lwork == -1; *info = 0; if (! lsame_(job, "E") && ! wantt) { *info = -1; } else if (! lsame_(compz, "N") && ! wantz) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*ilo < 1 || *ilo > max(1,*n)) { *info = -4; } else if (*ihi < min(*ilo,*n) || *ihi > *n) { *info = -5; } else if (*ldh < max(1,*n)) { *info = -7; } else if (*ldz < 1 || wantz && *ldz < max(1,*n)) { *info = -10; } else if (*lwork < max(1,*n) && ! lquery) { *info = -12; } if (*info != 0) { /* ==== Quick return in case of invalid argument. ==== */ i__1 = -(*info); xerbla_("ZHSEQR", &i__1); return 0; } else if (*n == 0) { /* ==== Quick return in case N = 0; nothing to do. ==== */ return 0; } else if (lquery) { /* ==== Quick return in case of a workspace query ==== */ zlaqr0_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &w[1], ilo, ihi, &z__[z_offset], ldz, &work[1], lwork, info); /* ==== Ensure reported workspace size is backward-compatible with . previous LAPACK versions. ==== Computing MAX */ d__2 = work[1].r, d__3 = (doublereal) max(1,*n); d__1 = max(d__2,d__3); z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; return 0; } else { /* ==== copy eigenvalues isolated by ZGEBAL ==== */ if (*ilo > 1) { i__1 = *ilo - 1; i__2 = *ldh + 1; zcopy_(&i__1, &h__[h_offset], &i__2, &w[1], &c__1); } if (*ihi < *n) { i__1 = *n - *ihi; i__2 = *ldh + 1; zcopy_(&i__1, &h__[*ihi + 1 + (*ihi + 1) * h_dim1], &i__2, &w[* ihi + 1], &c__1); } /* ==== Initialize Z, if requested ==== */ if (initz) { zlaset_("A", n, n, &c_b56, &c_b57, &z__[z_offset], ldz) ; } /* ==== Quick return if possible ==== */ if (*ilo == *ihi) { i__1 = *ilo; i__2 = *ilo + *ilo * h_dim1; w[i__1].r = h__[i__2].r, w[i__1].i = h__[i__2].i; return 0; } /* ==== ZLAHQR/ZLAQR0 crossover point ==== Writing concatenation */ i__3[0] = 1, a__1[0] = job; i__3[1] = 1, a__1[1] = compz; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); nmin = ilaenv_(&c__12, "ZHSEQR", ch__1, n, ilo, ihi, lwork, (ftnlen)6, (ftnlen)2); nmin = max(11,nmin); /* ==== ZLAQR0 for big matrices; ZLAHQR for small ones ==== */ if (*n > nmin) { zlaqr0_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &w[1], ilo, ihi, &z__[z_offset], ldz, &work[1], lwork, info); } else { /* ==== Small matrix ==== */ zlahqr_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &w[1], ilo, ihi, &z__[z_offset], ldz, info); if (*info > 0) { /* ==== A rare ZLAHQR failure! ZLAQR0 sometimes succeeds . when ZLAHQR fails. ==== */ kbot = *info; if (*n >= 49) { /* ==== Larger matrices have enough subdiagonal scratch . space to call ZLAQR0 directly. ==== */ zlaqr0_(&wantt, &wantz, n, ilo, &kbot, &h__[h_offset], ldh, &w[1], ilo, ihi, &z__[z_offset], ldz, &work[ 1], lwork, info); } else { /* ==== Tiny matrices don't have enough subdiagonal . scratch space to benefit from ZLAQR0. Hence, . tiny matrices must be copied into a larger . array before calling ZLAQR0. ==== */ zlacpy_("A", n, n, &h__[h_offset], ldh, hl, &c__49); i__1 = *n + 1 + *n * 49 - 50; hl[i__1].r = 0., hl[i__1].i = 0.; i__1 = 49 - *n; zlaset_("A", &c__49, &i__1, &c_b56, &c_b56, &hl[(*n + 1) * 49 - 49], &c__49); zlaqr0_(&wantt, &wantz, &c__49, ilo, &kbot, hl, &c__49, & w[1], ilo, ihi, &z__[z_offset], ldz, workl, & c__49, info); if (wantt || *info != 0) { zlacpy_("A", n, n, hl, &c__49, &h__[h_offset], ldh); } } } } /* ==== Clear out the trash, if necessary. ==== */ if ((wantt || *info != 0) && *n > 2) { i__1 = *n - 2; i__2 = *n - 2; zlaset_("L", &i__1, &i__2, &c_b56, &c_b56, &h__[h_dim1 + 3], ldh); } /* ==== Ensure reported workspace size is backward-compatible with . previous LAPACK versions. ==== Computing MAX */ d__2 = (doublereal) max(1,*n), d__3 = work[1].r; d__1 = max(d__2,d__3); z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; } /* ==== End of ZHSEQR ==== */ return 0; } /* zhseqr_ */ /* Subroutine */ int zlabrd_(integer *m, integer *n, integer *nb, doublecomplex *a, integer *lda, doublereal *d__, doublereal *e, doublecomplex *tauq, doublecomplex *taup, doublecomplex *x, integer * ldx, doublecomplex *y, integer *ldy) { /* System generated locals */ integer a_dim1, a_offset, x_dim1, x_offset, y_dim1, y_offset, i__1, i__2, i__3; doublecomplex z__1; /* Local variables */ static integer i__; static doublecomplex alpha; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *), zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlacgv_(integer *, doublecomplex *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLABRD reduces the first NB rows and columns of a complex general m by n matrix A to upper or lower real bidiagonal form by a unitary transformation Q' * A * P, and returns the matrices X and Y which are needed to apply the transformation to the unreduced part of A. If m >= n, A is reduced to upper bidiagonal form; if m < n, to lower bidiagonal form. This is an auxiliary routine called by ZGEBRD Arguments ========= M (input) INTEGER The number of rows in the matrix A. N (input) INTEGER The number of columns in the matrix A. NB (input) INTEGER The number of leading rows and columns of A to be reduced. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the m by n general matrix to be reduced. On exit, the first NB rows and columns of the matrix are overwritten; the rest of the array is unchanged. If m >= n, elements on and below the diagonal in the first NB columns, with the array TAUQ, represent the unitary matrix Q as a product of elementary reflectors; and elements above the diagonal in the first NB rows, with the array TAUP, represent the unitary matrix P as a product of elementary reflectors. If m < n, elements below the diagonal in the first NB columns, with the array TAUQ, represent the unitary matrix Q as a product of elementary reflectors, and elements on and above the diagonal in the first NB rows, with the array TAUP, represent the unitary matrix P as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). D (output) DOUBLE PRECISION array, dimension (NB) The diagonal elements of the first NB rows and columns of the reduced matrix. D(i) = A(i,i). E (output) DOUBLE PRECISION array, dimension (NB) The off-diagonal elements of the first NB rows and columns of the reduced matrix. TAUQ (output) COMPLEX*16 array dimension (NB) The scalar factors of the elementary reflectors which represent the unitary matrix Q. See Further Details. TAUP (output) COMPLEX*16 array, dimension (NB) The scalar factors of the elementary reflectors which represent the unitary matrix P. See Further Details. X (output) COMPLEX*16 array, dimension (LDX,NB) The m-by-nb matrix X required to update the unreduced part of A. LDX (input) INTEGER The leading dimension of the array X. LDX >= max(1,M). Y (output) COMPLEX*16 array, dimension (LDY,NB) The n-by-nb matrix Y required to update the unreduced part of A. LDY (input) INTEGER The leading dimension of the array Y. LDY >= max(1,N). Further Details =============== The matrices Q and P are represented as products of elementary reflectors: Q = H(1) H(2) . . . H(nb) and P = G(1) G(2) . . . G(nb) Each H(i) and G(i) has the form: H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' where tauq and taup are complex scalars, and v and u are complex vectors. If m >= n, v(1:i-1) = 0, v(i) = 1, and v(i:m) is stored on exit in A(i:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i). If m < n, v(1:i) = 0, v(i+1) = 1, and v(i+1:m) is stored on exit in A(i+2:m,i); u(1:i-1) = 0, u(i) = 1, and u(i:n) is stored on exit in A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i). The elements of the vectors v and u together form the m-by-nb matrix V and the nb-by-n matrix U' which are needed, with X and Y, to apply the transformation to the unreduced part of the matrix, using a block update of the form: A := A - V*Y' - X*U'. The contents of A on exit are illustrated by the following examples with nb = 2: m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n): ( 1 1 u1 u1 u1 ) ( 1 u1 u1 u1 u1 u1 ) ( v1 1 1 u2 u2 ) ( 1 1 u2 u2 u2 u2 ) ( v1 v2 a a a ) ( v1 1 a a a a ) ( v1 v2 a a a ) ( v1 v2 a a a a ) ( v1 v2 a a a ) ( v1 v2 a a a a ) ( v1 v2 a a a ) where a denotes an element of the original matrix which is unchanged, vi denotes an element of the vector defining H(i), and ui an element of the vector defining G(i). ===================================================================== Quick return if possible */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --d__; --e; --tauq; --taup; x_dim1 = *ldx; x_offset = 1 + x_dim1; x -= x_offset; y_dim1 = *ldy; y_offset = 1 + y_dim1; y -= y_offset; /* Function Body */ if (*m <= 0 || *n <= 0) { return 0; } if (*m >= *n) { /* Reduce to upper bidiagonal form */ i__1 = *nb; for (i__ = 1; i__ <= i__1; ++i__) { /* Update A(i:m,i) */ i__2 = i__ - 1; zlacgv_(&i__2, &y[i__ + y_dim1], ldy); i__2 = *m - i__ + 1; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[i__ + a_dim1], lda, &y[i__ + y_dim1], ldy, &c_b57, &a[i__ + i__ * a_dim1], & c__1); i__2 = i__ - 1; zlacgv_(&i__2, &y[i__ + y_dim1], ldy); i__2 = *m - i__ + 1; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &x[i__ + x_dim1], ldx, &a[i__ * a_dim1 + 1], &c__1, &c_b57, &a[i__ + i__ * a_dim1], &c__1); /* Generate reflection Q(i) to annihilate A(i+1:m,i) */ i__2 = i__ + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *m - i__ + 1; /* Computing MIN */ i__3 = i__ + 1; zlarfg_(&i__2, &alpha, &a[min(i__3,*m) + i__ * a_dim1], &c__1, & tauq[i__]); i__2 = i__; d__[i__2] = alpha.r; if (i__ < *n) { i__2 = i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute Y(i+1:n,i) */ i__2 = *m - i__ + 1; i__3 = *n - i__; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[i__ + ( i__ + 1) * a_dim1], lda, &a[i__ + i__ * a_dim1], & c__1, &c_b56, &y[i__ + 1 + i__ * y_dim1], &c__1); i__2 = *m - i__ + 1; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[i__ + a_dim1], lda, &a[i__ + i__ * a_dim1], &c__1, &c_b56, & y[i__ * y_dim1 + 1], &c__1); i__2 = *n - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &y[i__ + 1 + y_dim1], ldy, &y[i__ * y_dim1 + 1], &c__1, &c_b57, &y[ i__ + 1 + i__ * y_dim1], &c__1); i__2 = *m - i__ + 1; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &x[i__ + x_dim1], ldx, &a[i__ + i__ * a_dim1], &c__1, &c_b56, & y[i__ * y_dim1 + 1], &c__1); i__2 = i__ - 1; i__3 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("Conjugate transpose", &i__2, &i__3, &z__1, &a[(i__ + 1) * a_dim1 + 1], lda, &y[i__ * y_dim1 + 1], &c__1, & c_b57, &y[i__ + 1 + i__ * y_dim1], &c__1); i__2 = *n - i__; zscal_(&i__2, &tauq[i__], &y[i__ + 1 + i__ * y_dim1], &c__1); /* Update A(i,i+1:n) */ i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); zlacgv_(&i__, &a[i__ + a_dim1], lda); i__2 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__, &z__1, &y[i__ + 1 + y_dim1], ldy, &a[i__ + a_dim1], lda, &c_b57, &a[i__ + (i__ + 1) * a_dim1], lda); zlacgv_(&i__, &a[i__ + a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &x[i__ + x_dim1], ldx); i__2 = i__ - 1; i__3 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("Conjugate transpose", &i__2, &i__3, &z__1, &a[(i__ + 1) * a_dim1 + 1], lda, &x[i__ + x_dim1], ldx, &c_b57, &a[i__ + (i__ + 1) * a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &x[i__ + x_dim1], ldx); /* Generate reflection P(i) to annihilate A(i,i+2:n) */ i__2 = i__ + (i__ + 1) * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[i__ + min(i__3,*n) * a_dim1], lda, & taup[i__]); i__2 = i__; e[i__2] = alpha.r; i__2 = i__ + (i__ + 1) * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute X(i+1:m,i) */ i__2 = *m - i__; i__3 = *n - i__; zgemv_("No transpose", &i__2, &i__3, &c_b57, &a[i__ + 1 + ( i__ + 1) * a_dim1], lda, &a[i__ + (i__ + 1) * a_dim1], lda, &c_b56, &x[i__ + 1 + i__ * x_dim1], &c__1); i__2 = *n - i__; zgemv_("Conjugate transpose", &i__2, &i__, &c_b57, &y[i__ + 1 + y_dim1], ldy, &a[i__ + (i__ + 1) * a_dim1], lda, & c_b56, &x[i__ * x_dim1 + 1], &c__1); i__2 = *m - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__, &z__1, &a[i__ + 1 + a_dim1], lda, &x[i__ * x_dim1 + 1], &c__1, &c_b57, &x[ i__ + 1 + i__ * x_dim1], &c__1); i__2 = i__ - 1; i__3 = *n - i__; zgemv_("No transpose", &i__2, &i__3, &c_b57, &a[(i__ + 1) * a_dim1 + 1], lda, &a[i__ + (i__ + 1) * a_dim1], lda, & c_b56, &x[i__ * x_dim1 + 1], &c__1); i__2 = *m - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &x[i__ + 1 + x_dim1], ldx, &x[i__ * x_dim1 + 1], &c__1, &c_b57, &x[ i__ + 1 + i__ * x_dim1], &c__1); i__2 = *m - i__; zscal_(&i__2, &taup[i__], &x[i__ + 1 + i__ * x_dim1], &c__1); i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); } /* L10: */ } } else { /* Reduce to lower bidiagonal form */ i__1 = *nb; for (i__ = 1; i__ <= i__1; ++i__) { /* Update A(i,i:n) */ i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &a[i__ + a_dim1], lda); i__2 = *n - i__ + 1; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &y[i__ + y_dim1], ldy, &a[i__ + a_dim1], lda, &c_b57, &a[i__ + i__ * a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &a[i__ + a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &x[i__ + x_dim1], ldx); i__2 = i__ - 1; i__3 = *n - i__ + 1; z__1.r = -1., z__1.i = -0.; zgemv_("Conjugate transpose", &i__2, &i__3, &z__1, &a[i__ * a_dim1 + 1], lda, &x[i__ + x_dim1], ldx, &c_b57, &a[i__ + i__ * a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &x[i__ + x_dim1], ldx); /* Generate reflection P(i) to annihilate A(i,i+1:n) */ i__2 = i__ + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__ + 1; /* Computing MIN */ i__3 = i__ + 1; zlarfg_(&i__2, &alpha, &a[i__ + min(i__3,*n) * a_dim1], lda, & taup[i__]); i__2 = i__; d__[i__2] = alpha.r; if (i__ < *m) { i__2 = i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute X(i+1:m,i) */ i__2 = *m - i__; i__3 = *n - i__ + 1; zgemv_("No transpose", &i__2, &i__3, &c_b57, &a[i__ + 1 + i__ * a_dim1], lda, &a[i__ + i__ * a_dim1], lda, &c_b56, & x[i__ + 1 + i__ * x_dim1], &c__1); i__2 = *n - i__ + 1; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &y[i__ + y_dim1], ldy, &a[i__ + i__ * a_dim1], lda, &c_b56, &x[ i__ * x_dim1 + 1], &c__1); i__2 = *m - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[i__ + 1 + a_dim1], lda, &x[i__ * x_dim1 + 1], &c__1, &c_b57, &x[ i__ + 1 + i__ * x_dim1], &c__1); i__2 = i__ - 1; i__3 = *n - i__ + 1; zgemv_("No transpose", &i__2, &i__3, &c_b57, &a[i__ * a_dim1 + 1], lda, &a[i__ + i__ * a_dim1], lda, &c_b56, &x[ i__ * x_dim1 + 1], &c__1); i__2 = *m - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &x[i__ + 1 + x_dim1], ldx, &x[i__ * x_dim1 + 1], &c__1, &c_b57, &x[ i__ + 1 + i__ * x_dim1], &c__1); i__2 = *m - i__; zscal_(&i__2, &taup[i__], &x[i__ + 1 + i__ * x_dim1], &c__1); i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); /* Update A(i+1:m,i) */ i__2 = i__ - 1; zlacgv_(&i__2, &y[i__ + y_dim1], ldy); i__2 = *m - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[i__ + 1 + a_dim1], lda, &y[i__ + y_dim1], ldy, &c_b57, &a[i__ + 1 + i__ * a_dim1], &c__1); i__2 = i__ - 1; zlacgv_(&i__2, &y[i__ + y_dim1], ldy); i__2 = *m - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__, &z__1, &x[i__ + 1 + x_dim1], ldx, &a[i__ * a_dim1 + 1], &c__1, &c_b57, &a[ i__ + 1 + i__ * a_dim1], &c__1); /* Generate reflection Q(i) to annihilate A(i+2:m,i) */ i__2 = i__ + 1 + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *m - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[min(i__3,*m) + i__ * a_dim1], &c__1, &tauq[i__]); i__2 = i__; e[i__2] = alpha.r; i__2 = i__ + 1 + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute Y(i+1:n,i) */ i__2 = *m - i__; i__3 = *n - i__; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &a[i__ + 1 + i__ * a_dim1], &c__1, &c_b56, &y[i__ + 1 + i__ * y_dim1], & c__1); i__2 = *m - i__; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[i__ + 1 + a_dim1], lda, &a[i__ + 1 + i__ * a_dim1], &c__1, & c_b56, &y[i__ * y_dim1 + 1], &c__1); i__2 = *n - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &y[i__ + 1 + y_dim1], ldy, &y[i__ * y_dim1 + 1], &c__1, &c_b57, &y[ i__ + 1 + i__ * y_dim1], &c__1); i__2 = *m - i__; zgemv_("Conjugate transpose", &i__2, &i__, &c_b57, &x[i__ + 1 + x_dim1], ldx, &a[i__ + 1 + i__ * a_dim1], &c__1, & c_b56, &y[i__ * y_dim1 + 1], &c__1); i__2 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("Conjugate transpose", &i__, &i__2, &z__1, &a[(i__ + 1) * a_dim1 + 1], lda, &y[i__ * y_dim1 + 1], &c__1, & c_b57, &y[i__ + 1 + i__ * y_dim1], &c__1); i__2 = *n - i__; zscal_(&i__2, &tauq[i__], &y[i__ + 1 + i__ * y_dim1], &c__1); } else { i__2 = *n - i__ + 1; zlacgv_(&i__2, &a[i__ + i__ * a_dim1], lda); } /* L20: */ } } return 0; /* End of ZLABRD */ } /* zlabrd_ */ /* Subroutine */ int zlacgv_(integer *n, doublecomplex *x, integer *incx) { /* System generated locals */ integer i__1, i__2; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, ioff; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLACGV conjugates a complex vector of length N. Arguments ========= N (input) INTEGER The length of the vector X. N >= 0. X (input/output) COMPLEX*16 array, dimension (1+(N-1)*abs(INCX)) On entry, the vector of length N to be conjugated. On exit, X is overwritten with conjg(X). INCX (input) INTEGER The spacing between successive elements of X. ===================================================================== */ /* Parameter adjustments */ --x; /* Function Body */ if (*incx == 1) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__; d_cnjg(&z__1, &x[i__]); x[i__2].r = z__1.r, x[i__2].i = z__1.i; /* L10: */ } } else { ioff = 1; if (*incx < 0) { ioff = 1 - (*n - 1) * *incx; } i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = ioff; d_cnjg(&z__1, &x[ioff]); x[i__2].r = z__1.r, x[i__2].i = z__1.i; ioff += *incx; /* L20: */ } } return 0; /* End of ZLACGV */ } /* zlacgv_ */ /* Subroutine */ int zlacp2_(char *uplo, integer *m, integer *n, doublereal * a, integer *lda, doublecomplex *b, integer *ldb) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, j; extern logical lsame_(char *, char *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLACP2 copies all or part of a real two-dimensional matrix A to a complex matrix B. Arguments ========= UPLO (input) CHARACTER*1 Specifies the part of the matrix A to be copied to B. = 'U': Upper triangular part = 'L': Lower triangular part Otherwise: All of the matrix A M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input) DOUBLE PRECISION array, dimension (LDA,N) The m by n matrix A. If UPLO = 'U', only the upper trapezium is accessed; if UPLO = 'L', only the lower trapezium is accessed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). B (output) COMPLEX*16 array, dimension (LDB,N) On exit, B = A in the locations specified by UPLO. LDB (input) INTEGER The leading dimension of the array B. LDB >= max(1,M). ===================================================================== */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; /* Function Body */ if (lsame_(uplo, "U")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = min(j,*m); for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__ + j * a_dim1; b[i__3].r = a[i__4], b[i__3].i = 0.; /* L10: */ } /* L20: */ } } else if (lsame_(uplo, "L")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = j; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__ + j * a_dim1; b[i__3].r = a[i__4], b[i__3].i = 0.; /* L30: */ } /* L40: */ } } else { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__ + j * a_dim1; b[i__3].r = a[i__4], b[i__3].i = 0.; /* L50: */ } /* L60: */ } } return 0; /* End of ZLACP2 */ } /* zlacp2_ */ /* Subroutine */ int zlacpy_(char *uplo, integer *m, integer *n, doublecomplex *a, integer *lda, doublecomplex *b, integer *ldb) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, j; extern logical lsame_(char *, char *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLACPY copies all or part of a two-dimensional matrix A to another matrix B. Arguments ========= UPLO (input) CHARACTER*1 Specifies the part of the matrix A to be copied to B. = 'U': Upper triangular part = 'L': Lower triangular part Otherwise: All of the matrix A M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) The m by n matrix A. If UPLO = 'U', only the upper trapezium is accessed; if UPLO = 'L', only the lower trapezium is accessed. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). B (output) COMPLEX*16 array, dimension (LDB,N) On exit, B = A in the locations specified by UPLO. LDB (input) INTEGER The leading dimension of the array B. LDB >= max(1,M). ===================================================================== */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; /* Function Body */ if (lsame_(uplo, "U")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = min(j,*m); for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__ + j * a_dim1; b[i__3].r = a[i__4].r, b[i__3].i = a[i__4].i; /* L10: */ } /* L20: */ } } else if (lsame_(uplo, "L")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = j; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__ + j * a_dim1; b[i__3].r = a[i__4].r, b[i__3].i = a[i__4].i; /* L30: */ } /* L40: */ } } else { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__ + j * a_dim1; b[i__3].r = a[i__4].r, b[i__3].i = a[i__4].i; /* L50: */ } /* L60: */ } } return 0; /* End of ZLACPY */ } /* zlacpy_ */ /* Subroutine */ int zlacrm_(integer *m, integer *n, doublecomplex *a, integer *lda, doublereal *b, integer *ldb, doublecomplex *c__, integer *ldc, doublereal *rwork) { /* System generated locals */ integer b_dim1, b_offset, a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1; doublecomplex z__1; /* Builtin functions */ double d_imag(doublecomplex *); /* Local variables */ static integer i__, j, l; extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLACRM performs a very simple matrix-matrix multiplication: C := A * B, where A is M by N and complex; B is N by N and real; C is M by N and complex. Arguments ========= M (input) INTEGER The number of rows of the matrix A and of the matrix C. M >= 0. N (input) INTEGER The number of columns and rows of the matrix B and the number of columns of the matrix C. N >= 0. A (input) COMPLEX*16 array, dimension (LDA, N) A contains the M by N matrix A. LDA (input) INTEGER The leading dimension of the array A. LDA >=max(1,M). B (input) DOUBLE PRECISION array, dimension (LDB, N) B contains the N by N matrix B. LDB (input) INTEGER The leading dimension of the array B. LDB >=max(1,N). C (input) COMPLEX*16 array, dimension (LDC, N) C contains the M by N matrix C. LDC (input) INTEGER The leading dimension of the array C. LDC >=max(1,N). RWORK (workspace) DOUBLE PRECISION array, dimension (2*M*N) ===================================================================== Quick return if possible. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --rwork; /* Function Body */ if (*m == 0 || *n == 0) { return 0; } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; rwork[(j - 1) * *m + i__] = a[i__3].r; /* L10: */ } /* L20: */ } l = *m * *n + 1; dgemm_("N", "N", m, n, n, &c_b1034, &rwork[1], m, &b[b_offset], ldb, & c_b328, &rwork[l], m); i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * c_dim1; i__4 = l + (j - 1) * *m + i__ - 1; c__[i__3].r = rwork[i__4], c__[i__3].i = 0.; /* L30: */ } /* L40: */ } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { rwork[(j - 1) * *m + i__] = d_imag(&a[i__ + j * a_dim1]); /* L50: */ } /* L60: */ } dgemm_("N", "N", m, n, n, &c_b1034, &rwork[1], m, &b[b_offset], ldb, & c_b328, &rwork[l], m); i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * c_dim1; i__4 = i__ + j * c_dim1; d__1 = c__[i__4].r; i__5 = l + (j - 1) * *m + i__ - 1; z__1.r = d__1, z__1.i = rwork[i__5]; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L70: */ } /* L80: */ } return 0; /* End of ZLACRM */ } /* zlacrm_ */ /* Double Complex */ VOID zladiv_(doublecomplex * ret_val, doublecomplex *x, doublecomplex *y) { /* System generated locals */ doublereal d__1, d__2, d__3, d__4; doublecomplex z__1; /* Builtin functions */ double d_imag(doublecomplex *); /* Local variables */ static doublereal zi, zr; extern /* Subroutine */ int dladiv_(doublereal *, doublereal *, doublereal *, doublereal *, doublereal *, doublereal *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLADIV := X / Y, where X and Y are complex. The computation of X / Y will not overflow on an intermediary step unless the results overflows. Arguments ========= X (input) COMPLEX*16 Y (input) COMPLEX*16 The complex scalars X and Y. ===================================================================== */ d__1 = x->r; d__2 = d_imag(x); d__3 = y->r; d__4 = d_imag(y); dladiv_(&d__1, &d__2, &d__3, &d__4, &zr, &zi); z__1.r = zr, z__1.i = zi; ret_val->r = z__1.r, ret_val->i = z__1.i; return ; /* End of ZLADIV */ } /* zladiv_ */ /* Subroutine */ int zlaed0_(integer *qsiz, integer *n, doublereal *d__, doublereal *e, doublecomplex *q, integer *ldq, doublecomplex *qstore, integer *ldqs, doublereal *rwork, integer *iwork, integer *info) { /* System generated locals */ integer q_dim1, q_offset, qstore_dim1, qstore_offset, i__1, i__2; doublereal d__1; /* Builtin functions */ double log(doublereal); integer pow_ii(integer *, integer *); /* Local variables */ static integer i__, j, k, ll, iq, lgn, msd2, smm1, spm1, spm2; static doublereal temp; static integer curr, iperm; extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *, doublereal *, integer *); static integer indxq, iwrem, iqptr, tlvls; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaed7_(integer *, integer *, integer *, integer *, integer *, integer *, doublereal *, doublecomplex *, integer *, doublereal *, integer *, doublereal *, integer *, integer *, integer *, integer *, integer *, doublereal *, doublecomplex *, doublereal *, integer *, integer *) ; static integer igivcl; extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlacrm_(integer *, integer *, doublecomplex *, integer *, doublereal *, integer *, doublecomplex *, integer *, doublereal *); static integer igivnm, submat, curprb, subpbs, igivpt; extern /* Subroutine */ int dsteqr_(char *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *); static integer curlvl, matsiz, iprmpt, smlsiz; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= Using the divide and conquer method, ZLAED0 computes all eigenvalues of a symmetric tridiagonal matrix which is one diagonal block of those from reducing a dense or band Hermitian matrix and corresponding eigenvectors of the dense or band matrix. Arguments ========= QSIZ (input) INTEGER The dimension of the unitary matrix used to reduce the full matrix to tridiagonal form. QSIZ >= N if ICOMPQ = 1. N (input) INTEGER The dimension of the symmetric tridiagonal matrix. N >= 0. D (input/output) DOUBLE PRECISION array, dimension (N) On entry, the diagonal elements of the tridiagonal matrix. On exit, the eigenvalues in ascending order. E (input/output) DOUBLE PRECISION array, dimension (N-1) On entry, the off-diagonal elements of the tridiagonal matrix. On exit, E has been destroyed. Q (input/output) COMPLEX*16 array, dimension (LDQ,N) On entry, Q must contain an QSIZ x N matrix whose columns unitarily orthonormal. It is a part of the unitary matrix that reduces the full dense Hermitian matrix to a (reducible) symmetric tridiagonal matrix. LDQ (input) INTEGER The leading dimension of the array Q. LDQ >= max(1,N). IWORK (workspace) INTEGER array, the dimension of IWORK must be at least 6 + 6*N + 5*N*lg N ( lg( N ) = smallest integer k such that 2^k >= N ) RWORK (workspace) DOUBLE PRECISION array, dimension (1 + 3*N + 2*N*lg N + 3*N**2) ( lg( N ) = smallest integer k such that 2^k >= N ) QSTORE (workspace) COMPLEX*16 array, dimension (LDQS, N) Used to store parts of the eigenvector matrix when the updating matrix multiplies take place. LDQS (input) INTEGER The leading dimension of the array QSTORE. LDQS >= max(1,N). INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: The algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). ===================================================================== Warning: N could be as big as QSIZ! Test the input parameters. */ /* Parameter adjustments */ --d__; --e; q_dim1 = *ldq; q_offset = 1 + q_dim1; q -= q_offset; qstore_dim1 = *ldqs; qstore_offset = 1 + qstore_dim1; qstore -= qstore_offset; --rwork; --iwork; /* Function Body */ *info = 0; /* IF( ICOMPQ .LT. 0 .OR. ICOMPQ .GT. 2 ) THEN INFO = -1 ELSE IF( ( ICOMPQ .EQ. 1 ) .AND. ( QSIZ .LT. MAX( 0, N ) ) ) $ THEN */ if (*qsiz < max(0,*n)) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*ldq < max(1,*n)) { *info = -6; } else if (*ldqs < max(1,*n)) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLAED0", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } smlsiz = ilaenv_(&c__9, "ZLAED0", " ", &c__0, &c__0, &c__0, &c__0, ( ftnlen)6, (ftnlen)1); /* Determine the size and placement of the submatrices, and save in the leading elements of IWORK. */ iwork[1] = *n; subpbs = 1; tlvls = 0; L10: if (iwork[subpbs] > smlsiz) { for (j = subpbs; j >= 1; --j) { iwork[j * 2] = (iwork[j] + 1) / 2; iwork[(j << 1) - 1] = iwork[j] / 2; /* L20: */ } ++tlvls; subpbs <<= 1; goto L10; } i__1 = subpbs; for (j = 2; j <= i__1; ++j) { iwork[j] += iwork[j - 1]; /* L30: */ } /* Divide the matrix into SUBPBS submatrices of size at most SMLSIZ+1 using rank-1 modifications (cuts). */ spm1 = subpbs - 1; i__1 = spm1; for (i__ = 1; i__ <= i__1; ++i__) { submat = iwork[i__] + 1; smm1 = submat - 1; d__[smm1] -= (d__1 = e[smm1], abs(d__1)); d__[submat] -= (d__1 = e[smm1], abs(d__1)); /* L40: */ } indxq = (*n << 2) + 3; /* Set up workspaces for eigenvalues only/accumulate new vectors routine */ temp = log((doublereal) (*n)) / log(2.); lgn = (integer) temp; if (pow_ii(&c__2, &lgn) < *n) { ++lgn; } if (pow_ii(&c__2, &lgn) < *n) { ++lgn; } iprmpt = indxq + *n + 1; iperm = iprmpt + *n * lgn; iqptr = iperm + *n * lgn; igivpt = iqptr + *n + 2; igivcl = igivpt + *n * lgn; igivnm = 1; iq = igivnm + (*n << 1) * lgn; /* Computing 2nd power */ i__1 = *n; iwrem = iq + i__1 * i__1 + 1; /* Initialize pointers */ i__1 = subpbs; for (i__ = 0; i__ <= i__1; ++i__) { iwork[iprmpt + i__] = 1; iwork[igivpt + i__] = 1; /* L50: */ } iwork[iqptr] = 1; /* Solve each submatrix eigenproblem at the bottom of the divide and conquer tree. */ curr = 0; i__1 = spm1; for (i__ = 0; i__ <= i__1; ++i__) { if (i__ == 0) { submat = 1; matsiz = iwork[1]; } else { submat = iwork[i__] + 1; matsiz = iwork[i__ + 1] - iwork[i__]; } ll = iq - 1 + iwork[iqptr + curr]; dsteqr_("I", &matsiz, &d__[submat], &e[submat], &rwork[ll], &matsiz, & rwork[1], info); zlacrm_(qsiz, &matsiz, &q[submat * q_dim1 + 1], ldq, &rwork[ll], & matsiz, &qstore[submat * qstore_dim1 + 1], ldqs, &rwork[iwrem] ); /* Computing 2nd power */ i__2 = matsiz; iwork[iqptr + curr + 1] = iwork[iqptr + curr] + i__2 * i__2; ++curr; if (*info > 0) { *info = submat * (*n + 1) + submat + matsiz - 1; return 0; } k = 1; i__2 = iwork[i__ + 1]; for (j = submat; j <= i__2; ++j) { iwork[indxq + j] = k; ++k; /* L60: */ } /* L70: */ } /* Successively merge eigensystems of adjacent submatrices into eigensystem for the corresponding larger matrix. while ( SUBPBS > 1 ) */ curlvl = 1; L80: if (subpbs > 1) { spm2 = subpbs - 2; i__1 = spm2; for (i__ = 0; i__ <= i__1; i__ += 2) { if (i__ == 0) { submat = 1; matsiz = iwork[2]; msd2 = iwork[1]; curprb = 0; } else { submat = iwork[i__] + 1; matsiz = iwork[i__ + 2] - iwork[i__]; msd2 = matsiz / 2; ++curprb; } /* Merge lower order eigensystems (of size MSD2 and MATSIZ - MSD2) into an eigensystem of size MATSIZ. ZLAED7 handles the case when the eigenvectors of a full or band Hermitian matrix (which was reduced to tridiagonal form) are desired. I am free to use Q as a valuable working space until Loop 150. */ zlaed7_(&matsiz, &msd2, qsiz, &tlvls, &curlvl, &curprb, &d__[ submat], &qstore[submat * qstore_dim1 + 1], ldqs, &e[ submat + msd2 - 1], &iwork[indxq + submat], &rwork[iq], & iwork[iqptr], &iwork[iprmpt], &iwork[iperm], &iwork[ igivpt], &iwork[igivcl], &rwork[igivnm], &q[submat * q_dim1 + 1], &rwork[iwrem], &iwork[subpbs + 1], info); if (*info > 0) { *info = submat * (*n + 1) + submat + matsiz - 1; return 0; } iwork[i__ / 2 + 1] = iwork[i__ + 2]; /* L90: */ } subpbs /= 2; ++curlvl; goto L80; } /* end while Re-merge the eigenvalues/vectors which were deflated at the final merge step. */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { j = iwork[indxq + i__]; rwork[i__] = d__[j]; zcopy_(qsiz, &qstore[j * qstore_dim1 + 1], &c__1, &q[i__ * q_dim1 + 1] , &c__1); /* L100: */ } dcopy_(n, &rwork[1], &c__1, &d__[1], &c__1); return 0; /* End of ZLAED0 */ } /* zlaed0_ */ /* Subroutine */ int zlaed7_(integer *n, integer *cutpnt, integer *qsiz, integer *tlvls, integer *curlvl, integer *curpbm, doublereal *d__, doublecomplex *q, integer *ldq, doublereal *rho, integer *indxq, doublereal *qstore, integer *qptr, integer *prmptr, integer *perm, integer *givptr, integer *givcol, doublereal *givnum, doublecomplex * work, doublereal *rwork, integer *iwork, integer *info) { /* System generated locals */ integer q_dim1, q_offset, i__1, i__2; /* Builtin functions */ integer pow_ii(integer *, integer *); /* Local variables */ static integer i__, k, n1, n2, iq, iw, iz, ptr, indx, curr, indxc, indxp; extern /* Subroutine */ int dlaed9_(integer *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *), zlaed8_(integer *, integer *, integer *, doublecomplex *, integer *, doublereal *, doublereal *, integer *, doublereal *, doublereal *, doublecomplex *, integer *, doublereal *, integer *, integer *, integer *, integer *, integer *, integer *, doublereal *, integer *), dlaeda_(integer *, integer *, integer *, integer *, integer *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, doublereal *, integer *); static integer idlmda; extern /* Subroutine */ int dlamrg_(integer *, integer *, doublereal *, integer *, integer *, integer *), xerbla_(char *, integer *), zlacrm_(integer *, integer *, doublecomplex *, integer *, doublereal *, integer *, doublecomplex *, integer *, doublereal * ); static integer coltyp; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLAED7 computes the updated eigensystem of a diagonal matrix after modification by a rank-one symmetric matrix. This routine is used only for the eigenproblem which requires all eigenvalues and optionally eigenvectors of a dense or banded Hermitian matrix that has been reduced to tridiagonal form. T = Q(in) ( D(in) + RHO * Z*Z' ) Q'(in) = Q(out) * D(out) * Q'(out) where Z = Q'u, u is a vector of length N with ones in the CUTPNT and CUTPNT + 1 th elements and zeros elsewhere. The eigenvectors of the original matrix are stored in Q, and the eigenvalues are in D. The algorithm consists of three stages: The first stage consists of deflating the size of the problem when there are multiple eigenvalues or if there is a zero in the Z vector. For each such occurence the dimension of the secular equation problem is reduced by one. This stage is performed by the routine DLAED2. The second stage consists of calculating the updated eigenvalues. This is done by finding the roots of the secular equation via the routine DLAED4 (as called by SLAED3). This routine also calculates the eigenvectors of the current problem. The final stage consists of computing the updated eigenvectors directly using the updated eigenvalues. The eigenvectors for the current problem are multiplied with the eigenvectors from the overall problem. Arguments ========= N (input) INTEGER The dimension of the symmetric tridiagonal matrix. N >= 0. CUTPNT (input) INTEGER Contains the location of the last eigenvalue in the leading sub-matrix. min(1,N) <= CUTPNT <= N. QSIZ (input) INTEGER The dimension of the unitary matrix used to reduce the full matrix to tridiagonal form. QSIZ >= N. TLVLS (input) INTEGER The total number of merging levels in the overall divide and conquer tree. CURLVL (input) INTEGER The current level in the overall merge routine, 0 <= curlvl <= tlvls. CURPBM (input) INTEGER The current problem in the current level in the overall merge routine (counting from upper left to lower right). D (input/output) DOUBLE PRECISION array, dimension (N) On entry, the eigenvalues of the rank-1-perturbed matrix. On exit, the eigenvalues of the repaired matrix. Q (input/output) COMPLEX*16 array, dimension (LDQ,N) On entry, the eigenvectors of the rank-1-perturbed matrix. On exit, the eigenvectors of the repaired tridiagonal matrix. LDQ (input) INTEGER The leading dimension of the array Q. LDQ >= max(1,N). RHO (input) DOUBLE PRECISION Contains the subdiagonal element used to create the rank-1 modification. INDXQ (output) INTEGER array, dimension (N) This contains the permutation which will reintegrate the subproblem just solved back into sorted order, ie. D( INDXQ( I = 1, N ) ) will be in ascending order. IWORK (workspace) INTEGER array, dimension (4*N) RWORK (workspace) DOUBLE PRECISION array, dimension (3*N+2*QSIZ*N) WORK (workspace) COMPLEX*16 array, dimension (QSIZ*N) QSTORE (input/output) DOUBLE PRECISION array, dimension (N**2+1) Stores eigenvectors of submatrices encountered during divide and conquer, packed together. QPTR points to beginning of the submatrices. QPTR (input/output) INTEGER array, dimension (N+2) List of indices pointing to beginning of submatrices stored in QSTORE. The submatrices are numbered starting at the bottom left of the divide and conquer tree, from left to right and bottom to top. PRMPTR (input) INTEGER array, dimension (N lg N) Contains a list of pointers which indicate where in PERM a level's permutation is stored. PRMPTR(i+1) - PRMPTR(i) indicates the size of the permutation and also the size of the full, non-deflated problem. PERM (input) INTEGER array, dimension (N lg N) Contains the permutations (from deflation and sorting) to be applied to each eigenblock. GIVPTR (input) INTEGER array, dimension (N lg N) Contains a list of pointers which indicate where in GIVCOL a level's Givens rotations are stored. GIVPTR(i+1) - GIVPTR(i) indicates the number of Givens rotations. GIVCOL (input) INTEGER array, dimension (2, N lg N) Each pair of numbers indicates a pair of columns to take place in a Givens rotation. GIVNUM (input) DOUBLE PRECISION array, dimension (2, N lg N) Each number indicates the S value to be used in the corresponding Givens rotation. INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: if INFO = 1, an eigenvalue did not converge ===================================================================== Test the input parameters. */ /* Parameter adjustments */ --d__; q_dim1 = *ldq; q_offset = 1 + q_dim1; q -= q_offset; --indxq; --qstore; --qptr; --prmptr; --perm; --givptr; givcol -= 3; givnum -= 3; --work; --rwork; --iwork; /* Function Body */ *info = 0; /* IF( ICOMPQ.LT.0 .OR. ICOMPQ.GT.1 ) THEN INFO = -1 ELSE IF( N.LT.0 ) THEN */ if (*n < 0) { *info = -1; } else if (min(1,*n) > *cutpnt || *n < *cutpnt) { *info = -2; } else if (*qsiz < *n) { *info = -3; } else if (*ldq < max(1,*n)) { *info = -9; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLAED7", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* The following values are for bookkeeping purposes only. They are integer pointers which indicate the portion of the workspace used by a particular array in DLAED2 and SLAED3. */ iz = 1; idlmda = iz + *n; iw = idlmda + *n; iq = iw + *n; indx = 1; indxc = indx + *n; coltyp = indxc + *n; indxp = coltyp + *n; /* Form the z-vector which consists of the last row of Q_1 and the first row of Q_2. */ ptr = pow_ii(&c__2, tlvls) + 1; i__1 = *curlvl - 1; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = *tlvls - i__; ptr += pow_ii(&c__2, &i__2); /* L10: */ } curr = ptr + *curpbm; dlaeda_(n, tlvls, curlvl, curpbm, &prmptr[1], &perm[1], &givptr[1], & givcol[3], &givnum[3], &qstore[1], &qptr[1], &rwork[iz], &rwork[ iz + *n], info); /* When solving the final problem, we no longer need the stored data, so we will overwrite the data from this level onto the previously used storage space. */ if (*curlvl == *tlvls) { qptr[curr] = 1; prmptr[curr] = 1; givptr[curr] = 1; } /* Sort and Deflate eigenvalues. */ zlaed8_(&k, n, qsiz, &q[q_offset], ldq, &d__[1], rho, cutpnt, &rwork[iz], &rwork[idlmda], &work[1], qsiz, &rwork[iw], &iwork[indxp], &iwork[ indx], &indxq[1], &perm[prmptr[curr]], &givptr[curr + 1], &givcol[ (givptr[curr] << 1) + 1], &givnum[(givptr[curr] << 1) + 1], info); prmptr[curr + 1] = prmptr[curr] + *n; givptr[curr + 1] += givptr[curr]; /* Solve Secular Equation. */ if (k != 0) { dlaed9_(&k, &c__1, &k, n, &d__[1], &rwork[iq], &k, rho, &rwork[idlmda] , &rwork[iw], &qstore[qptr[curr]], &k, info); zlacrm_(qsiz, &k, &work[1], qsiz, &qstore[qptr[curr]], &k, &q[ q_offset], ldq, &rwork[iq]); /* Computing 2nd power */ i__1 = k; qptr[curr + 1] = qptr[curr] + i__1 * i__1; if (*info != 0) { return 0; } /* Prepare the INDXQ sorting premutation. */ n1 = k; n2 = *n - k; dlamrg_(&n1, &n2, &d__[1], &c__1, &c_n1, &indxq[1]); } else { qptr[curr + 1] = qptr[curr]; i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { indxq[i__] = i__; /* L20: */ } } return 0; /* End of ZLAED7 */ } /* zlaed7_ */ /* Subroutine */ int zlaed8_(integer *k, integer *n, integer *qsiz, doublecomplex *q, integer *ldq, doublereal *d__, doublereal *rho, integer *cutpnt, doublereal *z__, doublereal *dlamda, doublecomplex * q2, integer *ldq2, doublereal *w, integer *indxp, integer *indx, integer *indxq, integer *perm, integer *givptr, integer *givcol, doublereal *givnum, integer *info) { /* System generated locals */ integer q_dim1, q_offset, q2_dim1, q2_offset, i__1; doublereal d__1; /* Builtin functions */ double sqrt(doublereal); /* Local variables */ static doublereal c__; static integer i__, j; static doublereal s, t; static integer k2, n1, n2, jp, n1p1; static doublereal eps, tau, tol; static integer jlam, imax, jmax; extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, integer *), dcopy_(integer *, doublereal *, integer *, doublereal *, integer *), zdrot_(integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, doublereal *), zcopy_( integer *, doublecomplex *, integer *, doublecomplex *, integer *) ; extern integer idamax_(integer *, doublereal *, integer *); extern /* Subroutine */ int dlamrg_(integer *, integer *, doublereal *, integer *, integer *, integer *), xerbla_(char *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- June 2010 Purpose ======= ZLAED8 merges the two sets of eigenvalues together into a single sorted set. Then it tries to deflate the size of the problem. There are two ways in which deflation can occur: when two or more eigenvalues are close together or if there is a tiny element in the Z vector. For each such occurrence the order of the related secular equation problem is reduced by one. Arguments ========= K (output) INTEGER Contains the number of non-deflated eigenvalues. This is the order of the related secular equation. N (input) INTEGER The dimension of the symmetric tridiagonal matrix. N >= 0. QSIZ (input) INTEGER The dimension of the unitary matrix used to reduce the dense or band matrix to tridiagonal form. QSIZ >= N if ICOMPQ = 1. Q (input/output) COMPLEX*16 array, dimension (LDQ,N) On entry, Q contains the eigenvectors of the partially solved system which has been previously updated in matrix multiplies with other partially solved eigensystems. On exit, Q contains the trailing (N-K) updated eigenvectors (those which were deflated) in its last N-K columns. LDQ (input) INTEGER The leading dimension of the array Q. LDQ >= max( 1, N ). D (input/output) DOUBLE PRECISION array, dimension (N) On entry, D contains the eigenvalues of the two submatrices to be combined. On exit, D contains the trailing (N-K) updated eigenvalues (those which were deflated) sorted into increasing order. RHO (input/output) DOUBLE PRECISION Contains the off diagonal element associated with the rank-1 cut which originally split the two submatrices which are now being recombined. RHO is modified during the computation to the value required by DLAED3. CUTPNT (input) INTEGER Contains the location of the last eigenvalue in the leading sub-matrix. MIN(1,N) <= CUTPNT <= N. Z (input) DOUBLE PRECISION array, dimension (N) On input this vector contains the updating vector (the last row of the first sub-eigenvector matrix and the first row of the second sub-eigenvector matrix). The contents of Z are destroyed during the updating process. DLAMDA (output) DOUBLE PRECISION array, dimension (N) Contains a copy of the first K eigenvalues which will be used by DLAED3 to form the secular equation. Q2 (output) COMPLEX*16 array, dimension (LDQ2,N) If ICOMPQ = 0, Q2 is not referenced. Otherwise, Contains a copy of the first K eigenvectors which will be used by DLAED7 in a matrix multiply (DGEMM) to update the new eigenvectors. LDQ2 (input) INTEGER The leading dimension of the array Q2. LDQ2 >= max( 1, N ). W (output) DOUBLE PRECISION array, dimension (N) This will hold the first k values of the final deflation-altered z-vector and will be passed to DLAED3. INDXP (workspace) INTEGER array, dimension (N) This will contain the permutation used to place deflated values of D at the end of the array. On output INDXP(1:K) points to the nondeflated D-values and INDXP(K+1:N) points to the deflated eigenvalues. INDX (workspace) INTEGER array, dimension (N) This will contain the permutation used to sort the contents of D into ascending order. INDXQ (input) INTEGER array, dimension (N) This contains the permutation which separately sorts the two sub-problems in D into ascending order. Note that elements in the second half of this permutation must first have CUTPNT added to their values in order to be accurate. PERM (output) INTEGER array, dimension (N) Contains the permutations (from deflation and sorting) to be applied to each eigenblock. GIVPTR (output) INTEGER Contains the number of Givens rotations which took place in this subproblem. GIVCOL (output) INTEGER array, dimension (2, N) Each pair of numbers indicates a pair of columns to take place in a Givens rotation. GIVNUM (output) DOUBLE PRECISION array, dimension (2, N) Each number indicates the S value to be used in the corresponding Givens rotation. INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ q_dim1 = *ldq; q_offset = 1 + q_dim1; q -= q_offset; --d__; --z__; --dlamda; q2_dim1 = *ldq2; q2_offset = 1 + q2_dim1; q2 -= q2_offset; --w; --indxp; --indx; --indxq; --perm; givcol -= 3; givnum -= 3; /* Function Body */ *info = 0; if (*n < 0) { *info = -2; } else if (*qsiz < *n) { *info = -3; } else if (*ldq < max(1,*n)) { *info = -5; } else if (*cutpnt < min(1,*n) || *cutpnt > *n) { *info = -8; } else if (*ldq2 < max(1,*n)) { *info = -12; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLAED8", &i__1); return 0; } /* Need to initialize GIVPTR to O here in case of quick exit to prevent an unspecified code behavior (usually sigfault) when IWORK array on entry to *stedc is not zeroed (or at least some IWORK entries which used in *laed7 for GIVPTR). */ *givptr = 0; /* Quick return if possible */ if (*n == 0) { return 0; } n1 = *cutpnt; n2 = *n - n1; n1p1 = n1 + 1; if (*rho < 0.) { dscal_(&n2, &c_b1276, &z__[n1p1], &c__1); } /* Normalize z so that norm(z) = 1 */ t = 1. / sqrt(2.); i__1 = *n; for (j = 1; j <= i__1; ++j) { indx[j] = j; /* L10: */ } dscal_(n, &t, &z__[1], &c__1); *rho = (d__1 = *rho * 2., abs(d__1)); /* Sort the eigenvalues into increasing order */ i__1 = *n; for (i__ = *cutpnt + 1; i__ <= i__1; ++i__) { indxq[i__] += *cutpnt; /* L20: */ } i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { dlamda[i__] = d__[indxq[i__]]; w[i__] = z__[indxq[i__]]; /* L30: */ } i__ = 1; j = *cutpnt + 1; dlamrg_(&n1, &n2, &dlamda[1], &c__1, &c__1, &indx[1]); i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { d__[i__] = dlamda[indx[i__]]; z__[i__] = w[indx[i__]]; /* L40: */ } /* Calculate the allowable deflation tolerance */ imax = idamax_(n, &z__[1], &c__1); jmax = idamax_(n, &d__[1], &c__1); eps = EPSILON; tol = eps * 8. * (d__1 = d__[jmax], abs(d__1)); /* If the rank-1 modifier is small enough, no more needs to be done -- except to reorganize Q so that its columns correspond with the elements in D. */ if (*rho * (d__1 = z__[imax], abs(d__1)) <= tol) { *k = 0; i__1 = *n; for (j = 1; j <= i__1; ++j) { perm[j] = indxq[indx[j]]; zcopy_(qsiz, &q[perm[j] * q_dim1 + 1], &c__1, &q2[j * q2_dim1 + 1] , &c__1); /* L50: */ } zlacpy_("A", qsiz, n, &q2[q2_dim1 + 1], ldq2, &q[q_dim1 + 1], ldq); return 0; } /* If there are multiple eigenvalues then the problem deflates. Here the number of equal eigenvalues are found. As each equal eigenvalue is found, an elementary reflector is computed to rotate the corresponding eigensubspace so that the corresponding components of Z are zero in this new basis. */ *k = 0; k2 = *n + 1; i__1 = *n; for (j = 1; j <= i__1; ++j) { if (*rho * (d__1 = z__[j], abs(d__1)) <= tol) { /* Deflate due to small z component. */ --k2; indxp[k2] = j; if (j == *n) { goto L100; } } else { jlam = j; goto L70; } /* L60: */ } L70: ++j; if (j > *n) { goto L90; } if (*rho * (d__1 = z__[j], abs(d__1)) <= tol) { /* Deflate due to small z component. */ --k2; indxp[k2] = j; } else { /* Check if eigenvalues are close enough to allow deflation. */ s = z__[jlam]; c__ = z__[j]; /* Find sqrt(a**2+b**2) without overflow or destructive underflow. */ tau = dlapy2_(&c__, &s); t = d__[j] - d__[jlam]; c__ /= tau; s = -s / tau; if ((d__1 = t * c__ * s, abs(d__1)) <= tol) { /* Deflation is possible. */ z__[j] = tau; z__[jlam] = 0.; /* Record the appropriate Givens rotation */ ++(*givptr); givcol[(*givptr << 1) + 1] = indxq[indx[jlam]]; givcol[(*givptr << 1) + 2] = indxq[indx[j]]; givnum[(*givptr << 1) + 1] = c__; givnum[(*givptr << 1) + 2] = s; zdrot_(qsiz, &q[indxq[indx[jlam]] * q_dim1 + 1], &c__1, &q[indxq[ indx[j]] * q_dim1 + 1], &c__1, &c__, &s); t = d__[jlam] * c__ * c__ + d__[j] * s * s; d__[j] = d__[jlam] * s * s + d__[j] * c__ * c__; d__[jlam] = t; --k2; i__ = 1; L80: if (k2 + i__ <= *n) { if (d__[jlam] < d__[indxp[k2 + i__]]) { indxp[k2 + i__ - 1] = indxp[k2 + i__]; indxp[k2 + i__] = jlam; ++i__; goto L80; } else { indxp[k2 + i__ - 1] = jlam; } } else { indxp[k2 + i__ - 1] = jlam; } jlam = j; } else { ++(*k); w[*k] = z__[jlam]; dlamda[*k] = d__[jlam]; indxp[*k] = jlam; jlam = j; } } goto L70; L90: /* Record the last eigenvalue. */ ++(*k); w[*k] = z__[jlam]; dlamda[*k] = d__[jlam]; indxp[*k] = jlam; L100: /* Sort the eigenvalues and corresponding eigenvectors into DLAMDA and Q2 respectively. The eigenvalues/vectors which were not deflated go into the first K slots of DLAMDA and Q2 respectively, while those which were deflated go into the last N - K slots. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { jp = indxp[j]; dlamda[j] = d__[jp]; perm[j] = indxq[indx[jp]]; zcopy_(qsiz, &q[perm[j] * q_dim1 + 1], &c__1, &q2[j * q2_dim1 + 1], & c__1); /* L110: */ } /* The deflated eigenvalues and their corresponding vectors go back into the last N - K slots of D and Q respectively. */ if (*k < *n) { i__1 = *n - *k; dcopy_(&i__1, &dlamda[*k + 1], &c__1, &d__[*k + 1], &c__1); i__1 = *n - *k; zlacpy_("A", qsiz, &i__1, &q2[(*k + 1) * q2_dim1 + 1], ldq2, &q[(*k + 1) * q_dim1 + 1], ldq); } return 0; /* End of ZLAED8 */ } /* zlaed8_ */ /* Subroutine */ int zlahqr_(logical *wantt, logical *wantz, integer *n, integer *ilo, integer *ihi, doublecomplex *h__, integer *ldh, doublecomplex *w, integer *iloz, integer *ihiz, doublecomplex *z__, integer *ldz, integer *info) { /* System generated locals */ integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4; doublereal d__1, d__2, d__3, d__4, d__5, d__6; doublecomplex z__1, z__2, z__3, z__4, z__5, z__6, z__7; /* Builtin functions */ double d_imag(doublecomplex *); void d_cnjg(doublecomplex *, doublecomplex *); double z_abs(doublecomplex *); void z_sqrt(doublecomplex *, doublecomplex *), pow_zi(doublecomplex *, doublecomplex *, integer *); /* Local variables */ static integer i__, j, k, l, m; static doublereal s; static doublecomplex t, u, v[2], x, y; static integer i1, i2; static doublecomplex t1; static doublereal t2; static doublecomplex v2; static doublereal aa, ab, ba, bb, h10; static doublecomplex h11; static doublereal h21; static doublecomplex h22, sc; static integer nh, nz; static doublereal sx; static integer jhi; static doublecomplex h11s; static integer jlo, its; static doublereal ulp; static doublecomplex sum; static doublereal tst; static doublecomplex temp; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *); static doublereal rtemp; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), dlabad_(doublereal *, doublereal *); static doublereal safmin, safmax; extern /* Subroutine */ int zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); extern /* Double Complex */ VOID zladiv_(doublecomplex *, doublecomplex *, doublecomplex *); static doublereal smlnum; /* -- LAPACK auxiliary routine (version 3.2) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. November 2006 Purpose ======= ZLAHQR is an auxiliary routine called by CHSEQR to update the eigenvalues and Schur decomposition already computed by CHSEQR, by dealing with the Hessenberg submatrix in rows and columns ILO to IHI. Arguments ========= WANTT (input) LOGICAL = .TRUE. : the full Schur form T is required; = .FALSE.: only eigenvalues are required. WANTZ (input) LOGICAL = .TRUE. : the matrix of Schur vectors Z is required; = .FALSE.: Schur vectors are not required. N (input) INTEGER The order of the matrix H. N >= 0. ILO (input) INTEGER IHI (input) INTEGER It is assumed that H is already upper triangular in rows and columns IHI+1:N, and that H(ILO,ILO-1) = 0 (unless ILO = 1). ZLAHQR works primarily with the Hessenberg submatrix in rows and columns ILO to IHI, but applies transformations to all of H if WANTT is .TRUE.. 1 <= ILO <= max(1,IHI); IHI <= N. H (input/output) COMPLEX*16 array, dimension (LDH,N) On entry, the upper Hessenberg matrix H. On exit, if INFO is zero and if WANTT is .TRUE., then H is upper triangular in rows and columns ILO:IHI. If INFO is zero and if WANTT is .FALSE., then the contents of H are unspecified on exit. The output state of H in case INF is positive is below under the description of INFO. LDH (input) INTEGER The leading dimension of the array H. LDH >= max(1,N). W (output) COMPLEX*16 array, dimension (N) The computed eigenvalues ILO to IHI are stored in the corresponding elements of W. If WANTT is .TRUE., the eigenvalues are stored in the same order as on the diagonal of the Schur form returned in H, with W(i) = H(i,i). ILOZ (input) INTEGER IHIZ (input) INTEGER Specify the rows of Z to which transformations must be applied if WANTZ is .TRUE.. 1 <= ILOZ <= ILO; IHI <= IHIZ <= N. Z (input/output) COMPLEX*16 array, dimension (LDZ,N) If WANTZ is .TRUE., on entry Z must contain the current matrix Z of transformations accumulated by CHSEQR, and on exit Z has been updated; transformations are applied only to the submatrix Z(ILOZ:IHIZ,ILO:IHI). If WANTZ is .FALSE., Z is not referenced. LDZ (input) INTEGER The leading dimension of the array Z. LDZ >= max(1,N). INFO (output) INTEGER = 0: successful exit .GT. 0: if INFO = i, ZLAHQR failed to compute all the eigenvalues ILO to IHI in a total of 30 iterations per eigenvalue; elements i+1:ihi of W contain those eigenvalues which have been successfully computed. If INFO .GT. 0 and WANTT is .FALSE., then on exit, the remaining unconverged eigenvalues are the eigenvalues of the upper Hessenberg matrix rows and columns ILO thorugh INFO of the final, output value of H. If INFO .GT. 0 and WANTT is .TRUE., then on exit (*) (initial value of H)*U = U*(final value of H) where U is an orthognal matrix. The final value of H is upper Hessenberg and triangular in rows and columns INFO+1 through IHI. If INFO .GT. 0 and WANTZ is .TRUE., then on exit (final value of Z) = (initial value of Z)*U where U is the orthogonal matrix in (*) (regardless of the value of WANTT.) Further Details =============== 02-96 Based on modifications by David Day, Sandia National Laboratory, USA 12-04 Further modifications by Ralph Byers, University of Kansas, USA This is a modified version of ZLAHQR from LAPACK version 3.0. It is (1) more robust against overflow and underflow and (2) adopts the more conservative Ahues & Tisseur stopping criterion (LAWN 122, 1997). ========================================================= */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; --w; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; /* Function Body */ *info = 0; /* Quick return if possible */ if (*n == 0) { return 0; } if (*ilo == *ihi) { i__1 = *ilo; i__2 = *ilo + *ilo * h_dim1; w[i__1].r = h__[i__2].r, w[i__1].i = h__[i__2].i; return 0; } /* ==== clear out the trash ==== */ i__1 = *ihi - 3; for (j = *ilo; j <= i__1; ++j) { i__2 = j + 2 + j * h_dim1; h__[i__2].r = 0., h__[i__2].i = 0.; i__2 = j + 3 + j * h_dim1; h__[i__2].r = 0., h__[i__2].i = 0.; /* L10: */ } if (*ilo <= *ihi - 2) { i__1 = *ihi + (*ihi - 2) * h_dim1; h__[i__1].r = 0., h__[i__1].i = 0.; } /* ==== ensure that subdiagonal entries are real ==== */ if (*wantt) { jlo = 1; jhi = *n; } else { jlo = *ilo; jhi = *ihi; } i__1 = *ihi; for (i__ = *ilo + 1; i__ <= i__1; ++i__) { if (d_imag(&h__[i__ + (i__ - 1) * h_dim1]) != 0.) { /* ==== The following redundant normalization . avoids problems with both gradual and . sudden underflow in ABS(H(I,I-1)) ==== */ i__2 = i__ + (i__ - 1) * h_dim1; i__3 = i__ + (i__ - 1) * h_dim1; d__3 = (d__1 = h__[i__3].r, abs(d__1)) + (d__2 = d_imag(&h__[i__ + (i__ - 1) * h_dim1]), abs(d__2)); z__1.r = h__[i__2].r / d__3, z__1.i = h__[i__2].i / d__3; sc.r = z__1.r, sc.i = z__1.i; d_cnjg(&z__2, &sc); d__1 = z_abs(&sc); z__1.r = z__2.r / d__1, z__1.i = z__2.i / d__1; sc.r = z__1.r, sc.i = z__1.i; i__2 = i__ + (i__ - 1) * h_dim1; d__1 = z_abs(&h__[i__ + (i__ - 1) * h_dim1]); h__[i__2].r = d__1, h__[i__2].i = 0.; i__2 = jhi - i__ + 1; zscal_(&i__2, &sc, &h__[i__ + i__ * h_dim1], ldh); /* Computing MIN */ i__3 = jhi, i__4 = i__ + 1; i__2 = min(i__3,i__4) - jlo + 1; d_cnjg(&z__1, &sc); zscal_(&i__2, &z__1, &h__[jlo + i__ * h_dim1], &c__1); if (*wantz) { i__2 = *ihiz - *iloz + 1; d_cnjg(&z__1, &sc); zscal_(&i__2, &z__1, &z__[*iloz + i__ * z_dim1], &c__1); } } /* L20: */ } nh = *ihi - *ilo + 1; nz = *ihiz - *iloz + 1; /* Set machine-dependent constants for the stopping criterion. */ safmin = SAFEMINIMUM; safmax = 1. / safmin; dlabad_(&safmin, &safmax); ulp = PRECISION; smlnum = safmin * ((doublereal) nh / ulp); /* I1 and I2 are the indices of the first row and last column of H to which transformations must be applied. If eigenvalues only are being computed, I1 and I2 are set inside the main loop. */ if (*wantt) { i1 = 1; i2 = *n; } /* The main loop begins here. I is the loop index and decreases from IHI to ILO in steps of 1. Each iteration of the loop works with the active submatrix in rows and columns L to I. Eigenvalues I+1 to IHI have already converged. Either L = ILO, or H(L,L-1) is negligible so that the matrix splits. */ i__ = *ihi; L30: if (i__ < *ilo) { goto L150; } /* Perform QR iterations on rows and columns ILO to I until a submatrix of order 1 splits off at the bottom because a subdiagonal element has become negligible. */ l = *ilo; for (its = 0; its <= 30; ++its) { /* Look for a single small subdiagonal element. */ i__1 = l + 1; for (k = i__; k >= i__1; --k) { i__2 = k + (k - 1) * h_dim1; if ((d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[k + (k - 1) * h_dim1]), abs(d__2)) <= smlnum) { goto L50; } i__2 = k - 1 + (k - 1) * h_dim1; i__3 = k + k * h_dim1; tst = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[k - 1 + (k - 1) * h_dim1]), abs(d__2)) + ((d__3 = h__[i__3].r, abs(d__3)) + (d__4 = d_imag(&h__[k + k * h_dim1]), abs( d__4))); if (tst == 0.) { if (k - 2 >= *ilo) { i__2 = k - 1 + (k - 2) * h_dim1; tst += (d__1 = h__[i__2].r, abs(d__1)); } if (k + 1 <= *ihi) { i__2 = k + 1 + k * h_dim1; tst += (d__1 = h__[i__2].r, abs(d__1)); } } /* ==== The following is a conservative small subdiagonal . deflation criterion due to Ahues & Tisseur (LAWN 122, . 1997). It has better mathematical foundation and . improves accuracy in some examples. ==== */ i__2 = k + (k - 1) * h_dim1; if ((d__1 = h__[i__2].r, abs(d__1)) <= ulp * tst) { /* Computing MAX */ i__2 = k + (k - 1) * h_dim1; i__3 = k - 1 + k * h_dim1; d__5 = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[ k + (k - 1) * h_dim1]), abs(d__2)), d__6 = (d__3 = h__[i__3].r, abs(d__3)) + (d__4 = d_imag(&h__[k - 1 + k * h_dim1]), abs(d__4)); ab = max(d__5,d__6); /* Computing MIN */ i__2 = k + (k - 1) * h_dim1; i__3 = k - 1 + k * h_dim1; d__5 = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[ k + (k - 1) * h_dim1]), abs(d__2)), d__6 = (d__3 = h__[i__3].r, abs(d__3)) + (d__4 = d_imag(&h__[k - 1 + k * h_dim1]), abs(d__4)); ba = min(d__5,d__6); i__2 = k - 1 + (k - 1) * h_dim1; i__3 = k + k * h_dim1; z__2.r = h__[i__2].r - h__[i__3].r, z__2.i = h__[i__2].i - h__[i__3].i; z__1.r = z__2.r, z__1.i = z__2.i; /* Computing MAX */ i__4 = k + k * h_dim1; d__5 = (d__1 = h__[i__4].r, abs(d__1)) + (d__2 = d_imag(&h__[ k + k * h_dim1]), abs(d__2)), d__6 = (d__3 = z__1.r, abs(d__3)) + (d__4 = d_imag(&z__1), abs(d__4)); aa = max(d__5,d__6); i__2 = k - 1 + (k - 1) * h_dim1; i__3 = k + k * h_dim1; z__2.r = h__[i__2].r - h__[i__3].r, z__2.i = h__[i__2].i - h__[i__3].i; z__1.r = z__2.r, z__1.i = z__2.i; /* Computing MIN */ i__4 = k + k * h_dim1; d__5 = (d__1 = h__[i__4].r, abs(d__1)) + (d__2 = d_imag(&h__[ k + k * h_dim1]), abs(d__2)), d__6 = (d__3 = z__1.r, abs(d__3)) + (d__4 = d_imag(&z__1), abs(d__4)); bb = min(d__5,d__6); s = aa + ab; /* Computing MAX */ d__1 = smlnum, d__2 = ulp * (bb * (aa / s)); if (ba * (ab / s) <= max(d__1,d__2)) { goto L50; } } /* L40: */ } L50: l = k; if (l > *ilo) { /* H(L,L-1) is negligible */ i__1 = l + (l - 1) * h_dim1; h__[i__1].r = 0., h__[i__1].i = 0.; } /* Exit from loop if a submatrix of order 1 has split off. */ if (l >= i__) { goto L140; } /* Now the active submatrix is in rows and columns L to I. If eigenvalues only are being computed, only the active submatrix need be transformed. */ if (! (*wantt)) { i1 = l; i2 = i__; } if (its == 10) { /* Exceptional shift. */ i__1 = l + 1 + l * h_dim1; s = (d__1 = h__[i__1].r, abs(d__1)) * .75; i__1 = l + l * h_dim1; z__1.r = s + h__[i__1].r, z__1.i = h__[i__1].i; t.r = z__1.r, t.i = z__1.i; } else if (its == 20) { /* Exceptional shift. */ i__1 = i__ + (i__ - 1) * h_dim1; s = (d__1 = h__[i__1].r, abs(d__1)) * .75; i__1 = i__ + i__ * h_dim1; z__1.r = s + h__[i__1].r, z__1.i = h__[i__1].i; t.r = z__1.r, t.i = z__1.i; } else { /* Wilkinson's shift. */ i__1 = i__ + i__ * h_dim1; t.r = h__[i__1].r, t.i = h__[i__1].i; z_sqrt(&z__2, &h__[i__ - 1 + i__ * h_dim1]); z_sqrt(&z__3, &h__[i__ + (i__ - 1) * h_dim1]); z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i = z__2.r * z__3.i + z__2.i * z__3.r; u.r = z__1.r, u.i = z__1.i; s = (d__1 = u.r, abs(d__1)) + (d__2 = d_imag(&u), abs(d__2)); if (s != 0.) { i__1 = i__ - 1 + (i__ - 1) * h_dim1; z__2.r = h__[i__1].r - t.r, z__2.i = h__[i__1].i - t.i; z__1.r = z__2.r * .5, z__1.i = z__2.i * .5; x.r = z__1.r, x.i = z__1.i; sx = (d__1 = x.r, abs(d__1)) + (d__2 = d_imag(&x), abs(d__2)); /* Computing MAX */ d__3 = s, d__4 = (d__1 = x.r, abs(d__1)) + (d__2 = d_imag(&x), abs(d__2)); s = max(d__3,d__4); z__5.r = x.r / s, z__5.i = x.i / s; pow_zi(&z__4, &z__5, &c__2); z__7.r = u.r / s, z__7.i = u.i / s; pow_zi(&z__6, &z__7, &c__2); z__3.r = z__4.r + z__6.r, z__3.i = z__4.i + z__6.i; z_sqrt(&z__2, &z__3); z__1.r = s * z__2.r, z__1.i = s * z__2.i; y.r = z__1.r, y.i = z__1.i; if (sx > 0.) { z__1.r = x.r / sx, z__1.i = x.i / sx; z__2.r = x.r / sx, z__2.i = x.i / sx; if (z__1.r * y.r + d_imag(&z__2) * d_imag(&y) < 0.) { z__3.r = -y.r, z__3.i = -y.i; y.r = z__3.r, y.i = z__3.i; } } z__4.r = x.r + y.r, z__4.i = x.i + y.i; zladiv_(&z__3, &u, &z__4); z__2.r = u.r * z__3.r - u.i * z__3.i, z__2.i = u.r * z__3.i + u.i * z__3.r; z__1.r = t.r - z__2.r, z__1.i = t.i - z__2.i; t.r = z__1.r, t.i = z__1.i; } } /* Look for two consecutive small subdiagonal elements. */ i__1 = l + 1; for (m = i__ - 1; m >= i__1; --m) { /* Determine the effect of starting the single-shift QR iteration at row M, and see if this would make H(M,M-1) negligible. */ i__2 = m + m * h_dim1; h11.r = h__[i__2].r, h11.i = h__[i__2].i; i__2 = m + 1 + (m + 1) * h_dim1; h22.r = h__[i__2].r, h22.i = h__[i__2].i; z__1.r = h11.r - t.r, z__1.i = h11.i - t.i; h11s.r = z__1.r, h11s.i = z__1.i; i__2 = m + 1 + m * h_dim1; h21 = h__[i__2].r; s = (d__1 = h11s.r, abs(d__1)) + (d__2 = d_imag(&h11s), abs(d__2)) + abs(h21); z__1.r = h11s.r / s, z__1.i = h11s.i / s; h11s.r = z__1.r, h11s.i = z__1.i; h21 /= s; v[0].r = h11s.r, v[0].i = h11s.i; v[1].r = h21, v[1].i = 0.; i__2 = m + (m - 1) * h_dim1; h10 = h__[i__2].r; if (abs(h10) * abs(h21) <= ulp * (((d__1 = h11s.r, abs(d__1)) + ( d__2 = d_imag(&h11s), abs(d__2))) * ((d__3 = h11.r, abs( d__3)) + (d__4 = d_imag(&h11), abs(d__4)) + ((d__5 = h22.r, abs(d__5)) + (d__6 = d_imag(&h22), abs(d__6)))))) { goto L70; } /* L60: */ } i__1 = l + l * h_dim1; h11.r = h__[i__1].r, h11.i = h__[i__1].i; i__1 = l + 1 + (l + 1) * h_dim1; h22.r = h__[i__1].r, h22.i = h__[i__1].i; z__1.r = h11.r - t.r, z__1.i = h11.i - t.i; h11s.r = z__1.r, h11s.i = z__1.i; i__1 = l + 1 + l * h_dim1; h21 = h__[i__1].r; s = (d__1 = h11s.r, abs(d__1)) + (d__2 = d_imag(&h11s), abs(d__2)) + abs(h21); z__1.r = h11s.r / s, z__1.i = h11s.i / s; h11s.r = z__1.r, h11s.i = z__1.i; h21 /= s; v[0].r = h11s.r, v[0].i = h11s.i; v[1].r = h21, v[1].i = 0.; L70: /* Single-shift QR step */ i__1 = i__ - 1; for (k = m; k <= i__1; ++k) { /* The first iteration of this loop determines a reflection G from the vector V and applies it from left and right to H, thus creating a nonzero bulge below the subdiagonal. Each subsequent iteration determines a reflection G to restore the Hessenberg form in the (K-1)th column, and thus chases the bulge one step toward the bottom of the active submatrix. V(2) is always real before the call to ZLARFG, and hence after the call T2 ( = T1*V(2) ) is also real. */ if (k > m) { zcopy_(&c__2, &h__[k + (k - 1) * h_dim1], &c__1, v, &c__1); } zlarfg_(&c__2, v, &v[1], &c__1, &t1); if (k > m) { i__2 = k + (k - 1) * h_dim1; h__[i__2].r = v[0].r, h__[i__2].i = v[0].i; i__2 = k + 1 + (k - 1) * h_dim1; h__[i__2].r = 0., h__[i__2].i = 0.; } v2.r = v[1].r, v2.i = v[1].i; z__1.r = t1.r * v2.r - t1.i * v2.i, z__1.i = t1.r * v2.i + t1.i * v2.r; t2 = z__1.r; /* Apply G from the left to transform the rows of the matrix in columns K to I2. */ i__2 = i2; for (j = k; j <= i__2; ++j) { d_cnjg(&z__3, &t1); i__3 = k + j * h_dim1; z__2.r = z__3.r * h__[i__3].r - z__3.i * h__[i__3].i, z__2.i = z__3.r * h__[i__3].i + z__3.i * h__[i__3].r; i__4 = k + 1 + j * h_dim1; z__4.r = t2 * h__[i__4].r, z__4.i = t2 * h__[i__4].i; z__1.r = z__2.r + z__4.r, z__1.i = z__2.i + z__4.i; sum.r = z__1.r, sum.i = z__1.i; i__3 = k + j * h_dim1; i__4 = k + j * h_dim1; z__1.r = h__[i__4].r - sum.r, z__1.i = h__[i__4].i - sum.i; h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; i__3 = k + 1 + j * h_dim1; i__4 = k + 1 + j * h_dim1; z__2.r = sum.r * v2.r - sum.i * v2.i, z__2.i = sum.r * v2.i + sum.i * v2.r; z__1.r = h__[i__4].r - z__2.r, z__1.i = h__[i__4].i - z__2.i; h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; /* L80: */ } /* Apply G from the right to transform the columns of the matrix in rows I1 to min(K+2,I). Computing MIN */ i__3 = k + 2; i__2 = min(i__3,i__); for (j = i1; j <= i__2; ++j) { i__3 = j + k * h_dim1; z__2.r = t1.r * h__[i__3].r - t1.i * h__[i__3].i, z__2.i = t1.r * h__[i__3].i + t1.i * h__[i__3].r; i__4 = j + (k + 1) * h_dim1; z__3.r = t2 * h__[i__4].r, z__3.i = t2 * h__[i__4].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; sum.r = z__1.r, sum.i = z__1.i; i__3 = j + k * h_dim1; i__4 = j + k * h_dim1; z__1.r = h__[i__4].r - sum.r, z__1.i = h__[i__4].i - sum.i; h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; i__3 = j + (k + 1) * h_dim1; i__4 = j + (k + 1) * h_dim1; d_cnjg(&z__3, &v2); z__2.r = sum.r * z__3.r - sum.i * z__3.i, z__2.i = sum.r * z__3.i + sum.i * z__3.r; z__1.r = h__[i__4].r - z__2.r, z__1.i = h__[i__4].i - z__2.i; h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; /* L90: */ } if (*wantz) { /* Accumulate transformations in the matrix Z */ i__2 = *ihiz; for (j = *iloz; j <= i__2; ++j) { i__3 = j + k * z_dim1; z__2.r = t1.r * z__[i__3].r - t1.i * z__[i__3].i, z__2.i = t1.r * z__[i__3].i + t1.i * z__[i__3].r; i__4 = j + (k + 1) * z_dim1; z__3.r = t2 * z__[i__4].r, z__3.i = t2 * z__[i__4].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; sum.r = z__1.r, sum.i = z__1.i; i__3 = j + k * z_dim1; i__4 = j + k * z_dim1; z__1.r = z__[i__4].r - sum.r, z__1.i = z__[i__4].i - sum.i; z__[i__3].r = z__1.r, z__[i__3].i = z__1.i; i__3 = j + (k + 1) * z_dim1; i__4 = j + (k + 1) * z_dim1; d_cnjg(&z__3, &v2); z__2.r = sum.r * z__3.r - sum.i * z__3.i, z__2.i = sum.r * z__3.i + sum.i * z__3.r; z__1.r = z__[i__4].r - z__2.r, z__1.i = z__[i__4].i - z__2.i; z__[i__3].r = z__1.r, z__[i__3].i = z__1.i; /* L100: */ } } if (k == m && m > l) { /* If the QR step was started at row M > L because two consecutive small subdiagonals were found, then extra scaling must be performed to ensure that H(M,M-1) remains real. */ z__1.r = 1. - t1.r, z__1.i = 0. - t1.i; temp.r = z__1.r, temp.i = z__1.i; d__1 = z_abs(&temp); z__1.r = temp.r / d__1, z__1.i = temp.i / d__1; temp.r = z__1.r, temp.i = z__1.i; i__2 = m + 1 + m * h_dim1; i__3 = m + 1 + m * h_dim1; d_cnjg(&z__2, &temp); z__1.r = h__[i__3].r * z__2.r - h__[i__3].i * z__2.i, z__1.i = h__[i__3].r * z__2.i + h__[i__3].i * z__2.r; h__[i__2].r = z__1.r, h__[i__2].i = z__1.i; if (m + 2 <= i__) { i__2 = m + 2 + (m + 1) * h_dim1; i__3 = m + 2 + (m + 1) * h_dim1; z__1.r = h__[i__3].r * temp.r - h__[i__3].i * temp.i, z__1.i = h__[i__3].r * temp.i + h__[i__3].i * temp.r; h__[i__2].r = z__1.r, h__[i__2].i = z__1.i; } i__2 = i__; for (j = m; j <= i__2; ++j) { if (j != m + 1) { if (i2 > j) { i__3 = i2 - j; zscal_(&i__3, &temp, &h__[j + (j + 1) * h_dim1], ldh); } i__3 = j - i1; d_cnjg(&z__1, &temp); zscal_(&i__3, &z__1, &h__[i1 + j * h_dim1], &c__1); if (*wantz) { d_cnjg(&z__1, &temp); zscal_(&nz, &z__1, &z__[*iloz + j * z_dim1], & c__1); } } /* L110: */ } } /* L120: */ } /* Ensure that H(I,I-1) is real. */ i__1 = i__ + (i__ - 1) * h_dim1; temp.r = h__[i__1].r, temp.i = h__[i__1].i; if (d_imag(&temp) != 0.) { rtemp = z_abs(&temp); i__1 = i__ + (i__ - 1) * h_dim1; h__[i__1].r = rtemp, h__[i__1].i = 0.; z__1.r = temp.r / rtemp, z__1.i = temp.i / rtemp; temp.r = z__1.r, temp.i = z__1.i; if (i2 > i__) { i__1 = i2 - i__; d_cnjg(&z__1, &temp); zscal_(&i__1, &z__1, &h__[i__ + (i__ + 1) * h_dim1], ldh); } i__1 = i__ - i1; zscal_(&i__1, &temp, &h__[i1 + i__ * h_dim1], &c__1); if (*wantz) { zscal_(&nz, &temp, &z__[*iloz + i__ * z_dim1], &c__1); } } /* L130: */ } /* Failure to converge in remaining number of iterations */ *info = i__; return 0; L140: /* H(I,I-1) is negligible: one eigenvalue has converged. */ i__1 = i__; i__2 = i__ + i__ * h_dim1; w[i__1].r = h__[i__2].r, w[i__1].i = h__[i__2].i; /* return to start of the main loop with new value of I. */ i__ = l - 1; goto L30; L150: return 0; /* End of ZLAHQR */ } /* zlahqr_ */ /* Subroutine */ int zlahr2_(integer *n, integer *k, integer *nb, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *t, integer *ldt, doublecomplex *y, integer *ldy) { /* System generated locals */ integer a_dim1, a_offset, t_dim1, t_offset, y_dim1, y_offset, i__1, i__2, i__3; doublecomplex z__1; /* Local variables */ static integer i__; static doublecomplex ei; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *), zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), ztrmm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), ztrmv_(char *, char *, char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlacgv_(integer *, doublecomplex *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); /* -- LAPACK auxiliary routine (version 3.2.1) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -- April 2009 -- Purpose ======= ZLAHR2 reduces the first NB columns of A complex general n-BY-(n-k+1) matrix A so that elements below the k-th subdiagonal are zero. The reduction is performed by an unitary similarity transformation Q' * A * Q. The routine returns the matrices V and T which determine Q as a block reflector I - V*T*V', and also the matrix Y = A * V * T. This is an auxiliary routine called by ZGEHRD. Arguments ========= N (input) INTEGER The order of the matrix A. K (input) INTEGER The offset for the reduction. Elements below the k-th subdiagonal in the first NB columns are reduced to zero. K < N. NB (input) INTEGER The number of columns to be reduced. A (input/output) COMPLEX*16 array, dimension (LDA,N-K+1) On entry, the n-by-(n-k+1) general matrix A. On exit, the elements on and above the k-th subdiagonal in the first NB columns are overwritten with the corresponding elements of the reduced matrix; the elements below the k-th subdiagonal, with the array TAU, represent the matrix Q as a product of elementary reflectors. The other columns of A are unchanged. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). TAU (output) COMPLEX*16 array, dimension (NB) The scalar factors of the elementary reflectors. See Further Details. T (output) COMPLEX*16 array, dimension (LDT,NB) The upper triangular matrix T. LDT (input) INTEGER The leading dimension of the array T. LDT >= NB. Y (output) COMPLEX*16 array, dimension (LDY,NB) The n-by-nb matrix Y. LDY (input) INTEGER The leading dimension of the array Y. LDY >= N. Further Details =============== The matrix Q is represented as a product of nb elementary reflectors Q = H(1) H(2) . . . H(nb). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i+k-1) = 0, v(i+k) = 1; v(i+k+1:n) is stored on exit in A(i+k+1:n,i), and tau in TAU(i). The elements of the vectors v together form the (n-k+1)-by-nb matrix V which is needed, with T and Y, to apply the transformation to the unreduced part of the matrix, using an update of the form: A := (I - V*T*V') * (A - Y*V'). The contents of A on exit are illustrated by the following example with n = 7, k = 3 and nb = 2: ( a a a a a ) ( a a a a a ) ( a a a a a ) ( h h a a a ) ( v1 h a a a ) ( v1 v2 a a a ) ( v1 v2 a a a ) where a denotes an element of the original matrix A, h denotes a modified element of the upper Hessenberg matrix H, and vi denotes an element of the vector defining H(i). This subroutine is a slight modification of LAPACK-3.0's DLAHRD incorporating improvements proposed by Quintana-Orti and Van de Gejin. Note that the entries of A(1:K,2:NB) differ from those returned by the original LAPACK-3.0's DLAHRD routine. (This subroutine is not backward compatible with LAPACK-3.0's DLAHRD.) References ========== Gregorio Quintana-Orti and Robert van de Geijn, "Improving the performance of reduction to Hessenberg form," ACM Transactions on Mathematical Software, 32(2):180-194, June 2006. ===================================================================== Quick return if possible */ /* Parameter adjustments */ --tau; a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; y_dim1 = *ldy; y_offset = 1 + y_dim1; y -= y_offset; /* Function Body */ if (*n <= 1) { return 0; } i__1 = *nb; for (i__ = 1; i__ <= i__1; ++i__) { if (i__ > 1) { /* Update A(K+1:N,I) Update I-th column of A - Y * V' */ i__2 = i__ - 1; zlacgv_(&i__2, &a[*k + i__ - 1 + a_dim1], lda); i__2 = *n - *k; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("NO TRANSPOSE", &i__2, &i__3, &z__1, &y[*k + 1 + y_dim1], ldy, &a[*k + i__ - 1 + a_dim1], lda, &c_b57, &a[*k + 1 + i__ * a_dim1], &c__1); i__2 = i__ - 1; zlacgv_(&i__2, &a[*k + i__ - 1 + a_dim1], lda); /* Apply I - V * T' * V' to this column (call it b) from the left, using the last column of T as workspace Let V = ( V1 ) and b = ( b1 ) (first I-1 rows) ( V2 ) ( b2 ) where V1 is unit lower triangular w := V1' * b1 */ i__2 = i__ - 1; zcopy_(&i__2, &a[*k + 1 + i__ * a_dim1], &c__1, &t[*nb * t_dim1 + 1], &c__1); i__2 = i__ - 1; ztrmv_("Lower", "Conjugate transpose", "UNIT", &i__2, &a[*k + 1 + a_dim1], lda, &t[*nb * t_dim1 + 1], &c__1); /* w := w + V2'*b2 */ i__2 = *n - *k - i__ + 1; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[*k + i__ + a_dim1], lda, &a[*k + i__ + i__ * a_dim1], &c__1, &c_b57, &t[*nb * t_dim1 + 1], &c__1); /* w := T'*w */ i__2 = i__ - 1; ztrmv_("Upper", "Conjugate transpose", "NON-UNIT", &i__2, &t[ t_offset], ldt, &t[*nb * t_dim1 + 1], &c__1); /* b2 := b2 - V2*w */ i__2 = *n - *k - i__ + 1; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("NO TRANSPOSE", &i__2, &i__3, &z__1, &a[*k + i__ + a_dim1], lda, &t[*nb * t_dim1 + 1], &c__1, &c_b57, &a[*k + i__ + i__ * a_dim1], &c__1); /* b1 := b1 - V1*w */ i__2 = i__ - 1; ztrmv_("Lower", "NO TRANSPOSE", "UNIT", &i__2, &a[*k + 1 + a_dim1] , lda, &t[*nb * t_dim1 + 1], &c__1); i__2 = i__ - 1; z__1.r = -1., z__1.i = -0.; zaxpy_(&i__2, &z__1, &t[*nb * t_dim1 + 1], &c__1, &a[*k + 1 + i__ * a_dim1], &c__1); i__2 = *k + i__ - 1 + (i__ - 1) * a_dim1; a[i__2].r = ei.r, a[i__2].i = ei.i; } /* Generate the elementary reflector H(I) to annihilate A(K+I+1:N,I) */ i__2 = *n - *k - i__ + 1; /* Computing MIN */ i__3 = *k + i__ + 1; zlarfg_(&i__2, &a[*k + i__ + i__ * a_dim1], &a[min(i__3,*n) + i__ * a_dim1], &c__1, &tau[i__]); i__2 = *k + i__ + i__ * a_dim1; ei.r = a[i__2].r, ei.i = a[i__2].i; i__2 = *k + i__ + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute Y(K+1:N,I) */ i__2 = *n - *k; i__3 = *n - *k - i__ + 1; zgemv_("NO TRANSPOSE", &i__2, &i__3, &c_b57, &a[*k + 1 + (i__ + 1) * a_dim1], lda, &a[*k + i__ + i__ * a_dim1], &c__1, &c_b56, &y[* k + 1 + i__ * y_dim1], &c__1); i__2 = *n - *k - i__ + 1; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[*k + i__ + a_dim1], lda, &a[*k + i__ + i__ * a_dim1], &c__1, &c_b56, &t[ i__ * t_dim1 + 1], &c__1); i__2 = *n - *k; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("NO TRANSPOSE", &i__2, &i__3, &z__1, &y[*k + 1 + y_dim1], ldy, &t[i__ * t_dim1 + 1], &c__1, &c_b57, &y[*k + 1 + i__ * y_dim1] , &c__1); i__2 = *n - *k; zscal_(&i__2, &tau[i__], &y[*k + 1 + i__ * y_dim1], &c__1); /* Compute T(1:I,I) */ i__2 = i__ - 1; i__3 = i__; z__1.r = -tau[i__3].r, z__1.i = -tau[i__3].i; zscal_(&i__2, &z__1, &t[i__ * t_dim1 + 1], &c__1); i__2 = i__ - 1; ztrmv_("Upper", "No Transpose", "NON-UNIT", &i__2, &t[t_offset], ldt, &t[i__ * t_dim1 + 1], &c__1) ; i__2 = i__ + i__ * t_dim1; i__3 = i__; t[i__2].r = tau[i__3].r, t[i__2].i = tau[i__3].i; /* L10: */ } i__1 = *k + *nb + *nb * a_dim1; a[i__1].r = ei.r, a[i__1].i = ei.i; /* Compute Y(1:K,1:NB) */ zlacpy_("ALL", k, nb, &a[(a_dim1 << 1) + 1], lda, &y[y_offset], ldy); ztrmm_("RIGHT", "Lower", "NO TRANSPOSE", "UNIT", k, nb, &c_b57, &a[*k + 1 + a_dim1], lda, &y[y_offset], ldy); if (*n > *k + *nb) { i__1 = *n - *k - *nb; zgemm_("NO TRANSPOSE", "NO TRANSPOSE", k, nb, &i__1, &c_b57, &a[(*nb + 2) * a_dim1 + 1], lda, &a[*k + 1 + *nb + a_dim1], lda, & c_b57, &y[y_offset], ldy); } ztrmm_("RIGHT", "Upper", "NO TRANSPOSE", "NON-UNIT", k, nb, &c_b57, &t[ t_offset], ldt, &y[y_offset], ldy); return 0; /* End of ZLAHR2 */ } /* zlahr2_ */ /* Subroutine */ int zlals0_(integer *icompq, integer *nl, integer *nr, integer *sqre, integer *nrhs, doublecomplex *b, integer *ldb, doublecomplex *bx, integer *ldbx, integer *perm, integer *givptr, integer *givcol, integer *ldgcol, doublereal *givnum, integer *ldgnum, doublereal *poles, doublereal *difl, doublereal *difr, doublereal * z__, integer *k, doublereal *c__, doublereal *s, doublereal *rwork, integer *info) { /* System generated locals */ integer givcol_dim1, givcol_offset, difr_dim1, difr_offset, givnum_dim1, givnum_offset, poles_dim1, poles_offset, b_dim1, b_offset, bx_dim1, bx_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1; doublecomplex z__1; /* Builtin functions */ double d_imag(doublecomplex *); /* Local variables */ static integer i__, j, m, n; static doublereal dj; static integer nlp1, jcol; static doublereal temp; static integer jrow; extern doublereal dnrm2_(integer *, doublereal *, integer *); static doublereal diflj, difrj, dsigj; extern /* Subroutine */ int dgemv_(char *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *), zdrot_(integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, doublereal *); extern doublereal dlamc3_(doublereal *, doublereal *); extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); static doublereal dsigjp; extern /* Subroutine */ int zdscal_(integer *, doublereal *, doublecomplex *, integer *), zlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublecomplex * , integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLALS0 applies back the multiplying factors of either the left or the right singular vector matrix of a diagonal matrix appended by a row to the right hand side matrix B in solving the least squares problem using the divide-and-conquer SVD approach. For the left singular vector matrix, three types of orthogonal matrices are involved: (1L) Givens rotations: the number of such rotations is GIVPTR; the pairs of columns/rows they were applied to are stored in GIVCOL; and the C- and S-values of these rotations are stored in GIVNUM. (2L) Permutation. The (NL+1)-st row of B is to be moved to the first row, and for J=2:N, PERM(J)-th row of B is to be moved to the J-th row. (3L) The left singular vector matrix of the remaining matrix. For the right singular vector matrix, four types of orthogonal matrices are involved: (1R) The right singular vector matrix of the remaining matrix. (2R) If SQRE = 1, one extra Givens rotation to generate the right null space. (3R) The inverse transformation of (2L). (4R) The inverse transformation of (1L). Arguments ========= ICOMPQ (input) INTEGER Specifies whether singular vectors are to be computed in factored form: = 0: Left singular vector matrix. = 1: Right singular vector matrix. NL (input) INTEGER The row dimension of the upper block. NL >= 1. NR (input) INTEGER The row dimension of the lower block. NR >= 1. SQRE (input) INTEGER = 0: the lower block is an NR-by-NR square matrix. = 1: the lower block is an NR-by-(NR+1) rectangular matrix. The bidiagonal matrix has row dimension N = NL + NR + 1, and column dimension M = N + SQRE. NRHS (input) INTEGER The number of columns of B and BX. NRHS must be at least 1. B (input/output) COMPLEX*16 array, dimension ( LDB, NRHS ) On input, B contains the right hand sides of the least squares problem in rows 1 through M. On output, B contains the solution X in rows 1 through N. LDB (input) INTEGER The leading dimension of B. LDB must be at least max(1,MAX( M, N ) ). BX (workspace) COMPLEX*16 array, dimension ( LDBX, NRHS ) LDBX (input) INTEGER The leading dimension of BX. PERM (input) INTEGER array, dimension ( N ) The permutations (from deflation and sorting) applied to the two blocks. GIVPTR (input) INTEGER The number of Givens rotations which took place in this subproblem. GIVCOL (input) INTEGER array, dimension ( LDGCOL, 2 ) Each pair of numbers indicates a pair of rows/columns involved in a Givens rotation. LDGCOL (input) INTEGER The leading dimension of GIVCOL, must be at least N. GIVNUM (input) DOUBLE PRECISION array, dimension ( LDGNUM, 2 ) Each number indicates the C or S value used in the corresponding Givens rotation. LDGNUM (input) INTEGER The leading dimension of arrays DIFR, POLES and GIVNUM, must be at least K. POLES (input) DOUBLE PRECISION array, dimension ( LDGNUM, 2 ) On entry, POLES(1:K, 1) contains the new singular values obtained from solving the secular equation, and POLES(1:K, 2) is an array containing the poles in the secular equation. DIFL (input) DOUBLE PRECISION array, dimension ( K ). On entry, DIFL(I) is the distance between I-th updated (undeflated) singular value and the I-th (undeflated) old singular value. DIFR (input) DOUBLE PRECISION array, dimension ( LDGNUM, 2 ). On entry, DIFR(I, 1) contains the distances between I-th updated (undeflated) singular value and the I+1-th (undeflated) old singular value. And DIFR(I, 2) is the normalizing factor for the I-th right singular vector. Z (input) DOUBLE PRECISION array, dimension ( K ) Contain the components of the deflation-adjusted updating row vector. K (input) INTEGER Contains the dimension of the non-deflated matrix, This is the order of the related secular equation. 1 <= K <=N. C (input) DOUBLE PRECISION C contains garbage if SQRE =0 and the C-value of a Givens rotation related to the right null space if SQRE = 1. S (input) DOUBLE PRECISION S contains garbage if SQRE =0 and the S-value of a Givens rotation related to the right null space if SQRE = 1. RWORK (workspace) DOUBLE PRECISION array, dimension ( K*(1+NRHS) + 2*NRHS ) INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== Based on contributions by Ming Gu and Ren-Cang Li, Computer Science Division, University of California at Berkeley, USA Osni Marques, LBNL/NERSC, USA ===================================================================== Test the input parameters. */ /* Parameter adjustments */ b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; bx_dim1 = *ldbx; bx_offset = 1 + bx_dim1; bx -= bx_offset; --perm; givcol_dim1 = *ldgcol; givcol_offset = 1 + givcol_dim1; givcol -= givcol_offset; difr_dim1 = *ldgnum; difr_offset = 1 + difr_dim1; difr -= difr_offset; poles_dim1 = *ldgnum; poles_offset = 1 + poles_dim1; poles -= poles_offset; givnum_dim1 = *ldgnum; givnum_offset = 1 + givnum_dim1; givnum -= givnum_offset; --difl; --z__; --rwork; /* Function Body */ *info = 0; if (*icompq < 0 || *icompq > 1) { *info = -1; } else if (*nl < 1) { *info = -2; } else if (*nr < 1) { *info = -3; } else if (*sqre < 0 || *sqre > 1) { *info = -4; } n = *nl + *nr + 1; if (*nrhs < 1) { *info = -5; } else if (*ldb < n) { *info = -7; } else if (*ldbx < n) { *info = -9; } else if (*givptr < 0) { *info = -11; } else if (*ldgcol < n) { *info = -13; } else if (*ldgnum < n) { *info = -15; } else if (*k < 1) { *info = -20; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLALS0", &i__1); return 0; } m = n + *sqre; nlp1 = *nl + 1; if (*icompq == 0) { /* Apply back orthogonal transformations from the left. Step (1L): apply back the Givens rotations performed. */ i__1 = *givptr; for (i__ = 1; i__ <= i__1; ++i__) { zdrot_(nrhs, &b[givcol[i__ + (givcol_dim1 << 1)] + b_dim1], ldb, & b[givcol[i__ + givcol_dim1] + b_dim1], ldb, &givnum[i__ + (givnum_dim1 << 1)], &givnum[i__ + givnum_dim1]); /* L10: */ } /* Step (2L): permute rows of B. */ zcopy_(nrhs, &b[nlp1 + b_dim1], ldb, &bx[bx_dim1 + 1], ldbx); i__1 = n; for (i__ = 2; i__ <= i__1; ++i__) { zcopy_(nrhs, &b[perm[i__] + b_dim1], ldb, &bx[i__ + bx_dim1], ldbx); /* L20: */ } /* Step (3L): apply the inverse of the left singular vector matrix to BX. */ if (*k == 1) { zcopy_(nrhs, &bx[bx_offset], ldbx, &b[b_offset], ldb); if (z__[1] < 0.) { zdscal_(nrhs, &c_b1276, &b[b_offset], ldb); } } else { i__1 = *k; for (j = 1; j <= i__1; ++j) { diflj = difl[j]; dj = poles[j + poles_dim1]; dsigj = -poles[j + (poles_dim1 << 1)]; if (j < *k) { difrj = -difr[j + difr_dim1]; dsigjp = -poles[j + 1 + (poles_dim1 << 1)]; } if (z__[j] == 0. || poles[j + (poles_dim1 << 1)] == 0.) { rwork[j] = 0.; } else { rwork[j] = -poles[j + (poles_dim1 << 1)] * z__[j] / diflj / (poles[j + (poles_dim1 << 1)] + dj); } i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { if (z__[i__] == 0. || poles[i__ + (poles_dim1 << 1)] == 0.) { rwork[i__] = 0.; } else { rwork[i__] = poles[i__ + (poles_dim1 << 1)] * z__[i__] / (dlamc3_(&poles[i__ + (poles_dim1 << 1)], & dsigj) - diflj) / (poles[i__ + (poles_dim1 << 1)] + dj); } /* L30: */ } i__2 = *k; for (i__ = j + 1; i__ <= i__2; ++i__) { if (z__[i__] == 0. || poles[i__ + (poles_dim1 << 1)] == 0.) { rwork[i__] = 0.; } else { rwork[i__] = poles[i__ + (poles_dim1 << 1)] * z__[i__] / (dlamc3_(&poles[i__ + (poles_dim1 << 1)], & dsigjp) + difrj) / (poles[i__ + (poles_dim1 << 1)] + dj); } /* L40: */ } rwork[1] = -1.; temp = dnrm2_(k, &rwork[1], &c__1); /* Since B and BX are complex, the following call to DGEMV is performed in two steps (real and imaginary parts). CALL DGEMV( 'T', K, NRHS, ONE, BX, LDBX, WORK, 1, ZERO, $ B( J, 1 ), LDB ) */ i__ = *k + (*nrhs << 1); i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = *k; for (jrow = 1; jrow <= i__3; ++jrow) { ++i__; i__4 = jrow + jcol * bx_dim1; rwork[i__] = bx[i__4].r; /* L50: */ } /* L60: */ } dgemv_("T", k, nrhs, &c_b1034, &rwork[*k + 1 + (*nrhs << 1)], k, &rwork[1], &c__1, &c_b328, &rwork[*k + 1], &c__1); i__ = *k + (*nrhs << 1); i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = *k; for (jrow = 1; jrow <= i__3; ++jrow) { ++i__; rwork[i__] = d_imag(&bx[jrow + jcol * bx_dim1]); /* L70: */ } /* L80: */ } dgemv_("T", k, nrhs, &c_b1034, &rwork[*k + 1 + (*nrhs << 1)], k, &rwork[1], &c__1, &c_b328, &rwork[*k + 1 + *nrhs], &c__1); i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = j + jcol * b_dim1; i__4 = jcol + *k; i__5 = jcol + *k + *nrhs; z__1.r = rwork[i__4], z__1.i = rwork[i__5]; b[i__3].r = z__1.r, b[i__3].i = z__1.i; /* L90: */ } zlascl_("G", &c__0, &c__0, &temp, &c_b1034, &c__1, nrhs, &b[j + b_dim1], ldb, info); /* L100: */ } } /* Move the deflated rows of BX to B also. */ if (*k < max(m,n)) { i__1 = n - *k; zlacpy_("A", &i__1, nrhs, &bx[*k + 1 + bx_dim1], ldbx, &b[*k + 1 + b_dim1], ldb); } } else { /* Apply back the right orthogonal transformations. Step (1R): apply back the new right singular vector matrix to B. */ if (*k == 1) { zcopy_(nrhs, &b[b_offset], ldb, &bx[bx_offset], ldbx); } else { i__1 = *k; for (j = 1; j <= i__1; ++j) { dsigj = poles[j + (poles_dim1 << 1)]; if (z__[j] == 0.) { rwork[j] = 0.; } else { rwork[j] = -z__[j] / difl[j] / (dsigj + poles[j + poles_dim1]) / difr[j + (difr_dim1 << 1)]; } i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { if (z__[j] == 0.) { rwork[i__] = 0.; } else { d__1 = -poles[i__ + 1 + (poles_dim1 << 1)]; rwork[i__] = z__[j] / (dlamc3_(&dsigj, &d__1) - difr[ i__ + difr_dim1]) / (dsigj + poles[i__ + poles_dim1]) / difr[i__ + (difr_dim1 << 1)]; } /* L110: */ } i__2 = *k; for (i__ = j + 1; i__ <= i__2; ++i__) { if (z__[j] == 0.) { rwork[i__] = 0.; } else { d__1 = -poles[i__ + (poles_dim1 << 1)]; rwork[i__] = z__[j] / (dlamc3_(&dsigj, &d__1) - difl[ i__]) / (dsigj + poles[i__ + poles_dim1]) / difr[i__ + (difr_dim1 << 1)]; } /* L120: */ } /* Since B and BX are complex, the following call to DGEMV is performed in two steps (real and imaginary parts). CALL DGEMV( 'T', K, NRHS, ONE, B, LDB, WORK, 1, ZERO, $ BX( J, 1 ), LDBX ) */ i__ = *k + (*nrhs << 1); i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = *k; for (jrow = 1; jrow <= i__3; ++jrow) { ++i__; i__4 = jrow + jcol * b_dim1; rwork[i__] = b[i__4].r; /* L130: */ } /* L140: */ } dgemv_("T", k, nrhs, &c_b1034, &rwork[*k + 1 + (*nrhs << 1)], k, &rwork[1], &c__1, &c_b328, &rwork[*k + 1], &c__1); i__ = *k + (*nrhs << 1); i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = *k; for (jrow = 1; jrow <= i__3; ++jrow) { ++i__; rwork[i__] = d_imag(&b[jrow + jcol * b_dim1]); /* L150: */ } /* L160: */ } dgemv_("T", k, nrhs, &c_b1034, &rwork[*k + 1 + (*nrhs << 1)], k, &rwork[1], &c__1, &c_b328, &rwork[*k + 1 + *nrhs], &c__1); i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = j + jcol * bx_dim1; i__4 = jcol + *k; i__5 = jcol + *k + *nrhs; z__1.r = rwork[i__4], z__1.i = rwork[i__5]; bx[i__3].r = z__1.r, bx[i__3].i = z__1.i; /* L170: */ } /* L180: */ } } /* Step (2R): if SQRE = 1, apply back the rotation that is related to the right null space of the subproblem. */ if (*sqre == 1) { zcopy_(nrhs, &b[m + b_dim1], ldb, &bx[m + bx_dim1], ldbx); zdrot_(nrhs, &bx[bx_dim1 + 1], ldbx, &bx[m + bx_dim1], ldbx, c__, s); } if (*k < max(m,n)) { i__1 = n - *k; zlacpy_("A", &i__1, nrhs, &b[*k + 1 + b_dim1], ldb, &bx[*k + 1 + bx_dim1], ldbx); } /* Step (3R): permute rows of B. */ zcopy_(nrhs, &bx[bx_dim1 + 1], ldbx, &b[nlp1 + b_dim1], ldb); if (*sqre == 1) { zcopy_(nrhs, &bx[m + bx_dim1], ldbx, &b[m + b_dim1], ldb); } i__1 = n; for (i__ = 2; i__ <= i__1; ++i__) { zcopy_(nrhs, &bx[i__ + bx_dim1], ldbx, &b[perm[i__] + b_dim1], ldb); /* L190: */ } /* Step (4R): apply back the Givens rotations performed. */ for (i__ = *givptr; i__ >= 1; --i__) { d__1 = -givnum[i__ + givnum_dim1]; zdrot_(nrhs, &b[givcol[i__ + (givcol_dim1 << 1)] + b_dim1], ldb, & b[givcol[i__ + givcol_dim1] + b_dim1], ldb, &givnum[i__ + (givnum_dim1 << 1)], &d__1); /* L200: */ } } return 0; /* End of ZLALS0 */ } /* zlals0_ */ /* Subroutine */ int zlalsa_(integer *icompq, integer *smlsiz, integer *n, integer *nrhs, doublecomplex *b, integer *ldb, doublecomplex *bx, integer *ldbx, doublereal *u, integer *ldu, doublereal *vt, integer * k, doublereal *difl, doublereal *difr, doublereal *z__, doublereal * poles, integer *givptr, integer *givcol, integer *ldgcol, integer * perm, doublereal *givnum, doublereal *c__, doublereal *s, doublereal * rwork, integer *iwork, integer *info) { /* System generated locals */ integer givcol_dim1, givcol_offset, perm_dim1, perm_offset, difl_dim1, difl_offset, difr_dim1, difr_offset, givnum_dim1, givnum_offset, poles_dim1, poles_offset, u_dim1, u_offset, vt_dim1, vt_offset, z_dim1, z_offset, b_dim1, b_offset, bx_dim1, bx_offset, i__1, i__2, i__3, i__4, i__5, i__6; doublecomplex z__1; /* Builtin functions */ double d_imag(doublecomplex *); integer pow_ii(integer *, integer *); /* Local variables */ static integer i__, j, i1, ic, lf, nd, ll, nl, nr, im1, nlf, nrf, lvl, ndb1, nlp1, lvl2, nrp1, jcol, nlvl, sqre, jrow, jimag; extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *); static integer jreal, inode, ndiml, ndimr; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlals0_(integer *, integer *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, integer *), dlasdt_(integer *, integer *, integer * , integer *, integer *, integer *, integer *), xerbla_(char *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLALSA is an itermediate step in solving the least squares problem by computing the SVD of the coefficient matrix in compact form (The singular vectors are computed as products of simple orthorgonal matrices.). If ICOMPQ = 0, ZLALSA applies the inverse of the left singular vector matrix of an upper bidiagonal matrix to the right hand side; and if ICOMPQ = 1, ZLALSA applies the right singular vector matrix to the right hand side. The singular vector matrices were generated in compact form by ZLALSA. Arguments ========= ICOMPQ (input) INTEGER Specifies whether the left or the right singular vector matrix is involved. = 0: Left singular vector matrix = 1: Right singular vector matrix SMLSIZ (input) INTEGER The maximum size of the subproblems at the bottom of the computation tree. N (input) INTEGER The row and column dimensions of the upper bidiagonal matrix. NRHS (input) INTEGER The number of columns of B and BX. NRHS must be at least 1. B (input/output) COMPLEX*16 array, dimension ( LDB, NRHS ) On input, B contains the right hand sides of the least squares problem in rows 1 through M. On output, B contains the solution X in rows 1 through N. LDB (input) INTEGER The leading dimension of B in the calling subprogram. LDB must be at least max(1,MAX( M, N ) ). BX (output) COMPLEX*16 array, dimension ( LDBX, NRHS ) On exit, the result of applying the left or right singular vector matrix to B. LDBX (input) INTEGER The leading dimension of BX. U (input) DOUBLE PRECISION array, dimension ( LDU, SMLSIZ ). On entry, U contains the left singular vector matrices of all subproblems at the bottom level. LDU (input) INTEGER, LDU = > N. The leading dimension of arrays U, VT, DIFL, DIFR, POLES, GIVNUM, and Z. VT (input) DOUBLE PRECISION array, dimension ( LDU, SMLSIZ+1 ). On entry, VT' contains the right singular vector matrices of all subproblems at the bottom level. K (input) INTEGER array, dimension ( N ). DIFL (input) DOUBLE PRECISION array, dimension ( LDU, NLVL ). where NLVL = INT(log_2 (N/(SMLSIZ+1))) + 1. DIFR (input) DOUBLE PRECISION array, dimension ( LDU, 2 * NLVL ). On entry, DIFL(*, I) and DIFR(*, 2 * I -1) record distances between singular values on the I-th level and singular values on the (I -1)-th level, and DIFR(*, 2 * I) record the normalizing factors of the right singular vectors matrices of subproblems on I-th level. Z (input) DOUBLE PRECISION array, dimension ( LDU, NLVL ). On entry, Z(1, I) contains the components of the deflation- adjusted updating row vector for subproblems on the I-th level. POLES (input) DOUBLE PRECISION array, dimension ( LDU, 2 * NLVL ). On entry, POLES(*, 2 * I -1: 2 * I) contains the new and old singular values involved in the secular equations on the I-th level. GIVPTR (input) INTEGER array, dimension ( N ). On entry, GIVPTR( I ) records the number of Givens rotations performed on the I-th problem on the computation tree. GIVCOL (input) INTEGER array, dimension ( LDGCOL, 2 * NLVL ). On entry, for each I, GIVCOL(*, 2 * I - 1: 2 * I) records the locations of Givens rotations performed on the I-th level on the computation tree. LDGCOL (input) INTEGER, LDGCOL = > N. The leading dimension of arrays GIVCOL and PERM. PERM (input) INTEGER array, dimension ( LDGCOL, NLVL ). On entry, PERM(*, I) records permutations done on the I-th level of the computation tree. GIVNUM (input) DOUBLE PRECISION array, dimension ( LDU, 2 * NLVL ). On entry, GIVNUM(*, 2 *I -1 : 2 * I) records the C- and S- values of Givens rotations performed on the I-th level on the computation tree. C (input) DOUBLE PRECISION array, dimension ( N ). On entry, if the I-th subproblem is not square, C( I ) contains the C-value of a Givens rotation related to the right null space of the I-th subproblem. S (input) DOUBLE PRECISION array, dimension ( N ). On entry, if the I-th subproblem is not square, S( I ) contains the S-value of a Givens rotation related to the right null space of the I-th subproblem. RWORK (workspace) DOUBLE PRECISION array, dimension at least MAX( (SMLSZ+1)*NRHS*3, N*(1+NRHS) + 2*NRHS ). IWORK (workspace) INTEGER array. The dimension must be at least 3 * N INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. Further Details =============== Based on contributions by Ming Gu and Ren-Cang Li, Computer Science Division, University of California at Berkeley, USA Osni Marques, LBNL/NERSC, USA ===================================================================== Test the input parameters. */ /* Parameter adjustments */ b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; bx_dim1 = *ldbx; bx_offset = 1 + bx_dim1; bx -= bx_offset; givnum_dim1 = *ldu; givnum_offset = 1 + givnum_dim1; givnum -= givnum_offset; poles_dim1 = *ldu; poles_offset = 1 + poles_dim1; poles -= poles_offset; z_dim1 = *ldu; z_offset = 1 + z_dim1; z__ -= z_offset; difr_dim1 = *ldu; difr_offset = 1 + difr_dim1; difr -= difr_offset; difl_dim1 = *ldu; difl_offset = 1 + difl_dim1; difl -= difl_offset; vt_dim1 = *ldu; vt_offset = 1 + vt_dim1; vt -= vt_offset; u_dim1 = *ldu; u_offset = 1 + u_dim1; u -= u_offset; --k; --givptr; perm_dim1 = *ldgcol; perm_offset = 1 + perm_dim1; perm -= perm_offset; givcol_dim1 = *ldgcol; givcol_offset = 1 + givcol_dim1; givcol -= givcol_offset; --c__; --s; --rwork; --iwork; /* Function Body */ *info = 0; if (*icompq < 0 || *icompq > 1) { *info = -1; } else if (*smlsiz < 3) { *info = -2; } else if (*n < *smlsiz) { *info = -3; } else if (*nrhs < 1) { *info = -4; } else if (*ldb < *n) { *info = -6; } else if (*ldbx < *n) { *info = -8; } else if (*ldu < *n) { *info = -10; } else if (*ldgcol < *n) { *info = -19; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLALSA", &i__1); return 0; } /* Book-keeping and setting up the computation tree. */ inode = 1; ndiml = inode + *n; ndimr = ndiml + *n; dlasdt_(n, &nlvl, &nd, &iwork[inode], &iwork[ndiml], &iwork[ndimr], smlsiz); /* The following code applies back the left singular vector factors. For applying back the right singular vector factors, go to 170. */ if (*icompq == 1) { goto L170; } /* The nodes on the bottom level of the tree were solved by DLASDQ. The corresponding left and right singular vector matrices are in explicit form. First apply back the left singular vector matrices. */ ndb1 = (nd + 1) / 2; i__1 = nd; for (i__ = ndb1; i__ <= i__1; ++i__) { /* IC : center row of each node NL : number of rows of left subproblem NR : number of rows of right subproblem NLF: starting row of the left subproblem NRF: starting row of the right subproblem */ i1 = i__ - 1; ic = iwork[inode + i1]; nl = iwork[ndiml + i1]; nr = iwork[ndimr + i1]; nlf = ic - nl; nrf = ic + 1; /* Since B and BX are complex, the following call to DGEMM is performed in two steps (real and imaginary parts). CALL DGEMM( 'T', 'N', NL, NRHS, NL, ONE, U( NLF, 1 ), LDU, $ B( NLF, 1 ), LDB, ZERO, BX( NLF, 1 ), LDBX ) */ j = nl * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nlf + nl - 1; for (jrow = nlf; jrow <= i__3; ++jrow) { ++j; i__4 = jrow + jcol * b_dim1; rwork[j] = b[i__4].r; /* L10: */ } /* L20: */ } dgemm_("T", "N", &nl, nrhs, &nl, &c_b1034, &u[nlf + u_dim1], ldu, & rwork[(nl * *nrhs << 1) + 1], &nl, &c_b328, &rwork[1], &nl); j = nl * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nlf + nl - 1; for (jrow = nlf; jrow <= i__3; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L30: */ } /* L40: */ } dgemm_("T", "N", &nl, nrhs, &nl, &c_b1034, &u[nlf + u_dim1], ldu, & rwork[(nl * *nrhs << 1) + 1], &nl, &c_b328, &rwork[nl * *nrhs + 1], &nl); jreal = 0; jimag = nl * *nrhs; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nlf + nl - 1; for (jrow = nlf; jrow <= i__3; ++jrow) { ++jreal; ++jimag; i__4 = jrow + jcol * bx_dim1; i__5 = jreal; i__6 = jimag; z__1.r = rwork[i__5], z__1.i = rwork[i__6]; bx[i__4].r = z__1.r, bx[i__4].i = z__1.i; /* L50: */ } /* L60: */ } /* Since B and BX are complex, the following call to DGEMM is performed in two steps (real and imaginary parts). CALL DGEMM( 'T', 'N', NR, NRHS, NR, ONE, U( NRF, 1 ), LDU, $ B( NRF, 1 ), LDB, ZERO, BX( NRF, 1 ), LDBX ) */ j = nr * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nrf + nr - 1; for (jrow = nrf; jrow <= i__3; ++jrow) { ++j; i__4 = jrow + jcol * b_dim1; rwork[j] = b[i__4].r; /* L70: */ } /* L80: */ } dgemm_("T", "N", &nr, nrhs, &nr, &c_b1034, &u[nrf + u_dim1], ldu, & rwork[(nr * *nrhs << 1) + 1], &nr, &c_b328, &rwork[1], &nr); j = nr * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nrf + nr - 1; for (jrow = nrf; jrow <= i__3; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L90: */ } /* L100: */ } dgemm_("T", "N", &nr, nrhs, &nr, &c_b1034, &u[nrf + u_dim1], ldu, & rwork[(nr * *nrhs << 1) + 1], &nr, &c_b328, &rwork[nr * *nrhs + 1], &nr); jreal = 0; jimag = nr * *nrhs; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nrf + nr - 1; for (jrow = nrf; jrow <= i__3; ++jrow) { ++jreal; ++jimag; i__4 = jrow + jcol * bx_dim1; i__5 = jreal; i__6 = jimag; z__1.r = rwork[i__5], z__1.i = rwork[i__6]; bx[i__4].r = z__1.r, bx[i__4].i = z__1.i; /* L110: */ } /* L120: */ } /* L130: */ } /* Next copy the rows of B that correspond to unchanged rows in the bidiagonal matrix to BX. */ i__1 = nd; for (i__ = 1; i__ <= i__1; ++i__) { ic = iwork[inode + i__ - 1]; zcopy_(nrhs, &b[ic + b_dim1], ldb, &bx[ic + bx_dim1], ldbx); /* L140: */ } /* Finally go through the left singular vector matrices of all the other subproblems bottom-up on the tree. */ j = pow_ii(&c__2, &nlvl); sqre = 0; for (lvl = nlvl; lvl >= 1; --lvl) { lvl2 = (lvl << 1) - 1; /* find the first node LF and last node LL on the current level LVL */ if (lvl == 1) { lf = 1; ll = 1; } else { i__1 = lvl - 1; lf = pow_ii(&c__2, &i__1); ll = (lf << 1) - 1; } i__1 = ll; for (i__ = lf; i__ <= i__1; ++i__) { im1 = i__ - 1; ic = iwork[inode + im1]; nl = iwork[ndiml + im1]; nr = iwork[ndimr + im1]; nlf = ic - nl; nrf = ic + 1; --j; zlals0_(icompq, &nl, &nr, &sqre, nrhs, &bx[nlf + bx_dim1], ldbx, & b[nlf + b_dim1], ldb, &perm[nlf + lvl * perm_dim1], & givptr[j], &givcol[nlf + lvl2 * givcol_dim1], ldgcol, & givnum[nlf + lvl2 * givnum_dim1], ldu, &poles[nlf + lvl2 * poles_dim1], &difl[nlf + lvl * difl_dim1], &difr[nlf + lvl2 * difr_dim1], &z__[nlf + lvl * z_dim1], &k[j], &c__[ j], &s[j], &rwork[1], info); /* L150: */ } /* L160: */ } goto L330; /* ICOMPQ = 1: applying back the right singular vector factors. */ L170: /* First now go through the right singular vector matrices of all the tree nodes top-down. */ j = 0; i__1 = nlvl; for (lvl = 1; lvl <= i__1; ++lvl) { lvl2 = (lvl << 1) - 1; /* Find the first node LF and last node LL on the current level LVL. */ if (lvl == 1) { lf = 1; ll = 1; } else { i__2 = lvl - 1; lf = pow_ii(&c__2, &i__2); ll = (lf << 1) - 1; } i__2 = lf; for (i__ = ll; i__ >= i__2; --i__) { im1 = i__ - 1; ic = iwork[inode + im1]; nl = iwork[ndiml + im1]; nr = iwork[ndimr + im1]; nlf = ic - nl; nrf = ic + 1; if (i__ == ll) { sqre = 0; } else { sqre = 1; } ++j; zlals0_(icompq, &nl, &nr, &sqre, nrhs, &b[nlf + b_dim1], ldb, &bx[ nlf + bx_dim1], ldbx, &perm[nlf + lvl * perm_dim1], & givptr[j], &givcol[nlf + lvl2 * givcol_dim1], ldgcol, & givnum[nlf + lvl2 * givnum_dim1], ldu, &poles[nlf + lvl2 * poles_dim1], &difl[nlf + lvl * difl_dim1], &difr[nlf + lvl2 * difr_dim1], &z__[nlf + lvl * z_dim1], &k[j], &c__[ j], &s[j], &rwork[1], info); /* L180: */ } /* L190: */ } /* The nodes on the bottom level of the tree were solved by DLASDQ. The corresponding right singular vector matrices are in explicit form. Apply them back. */ ndb1 = (nd + 1) / 2; i__1 = nd; for (i__ = ndb1; i__ <= i__1; ++i__) { i1 = i__ - 1; ic = iwork[inode + i1]; nl = iwork[ndiml + i1]; nr = iwork[ndimr + i1]; nlp1 = nl + 1; if (i__ == nd) { nrp1 = nr; } else { nrp1 = nr + 1; } nlf = ic - nl; nrf = ic + 1; /* Since B and BX are complex, the following call to DGEMM is performed in two steps (real and imaginary parts). CALL DGEMM( 'T', 'N', NLP1, NRHS, NLP1, ONE, VT( NLF, 1 ), LDU, $ B( NLF, 1 ), LDB, ZERO, BX( NLF, 1 ), LDBX ) */ j = nlp1 * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nlf + nlp1 - 1; for (jrow = nlf; jrow <= i__3; ++jrow) { ++j; i__4 = jrow + jcol * b_dim1; rwork[j] = b[i__4].r; /* L200: */ } /* L210: */ } dgemm_("T", "N", &nlp1, nrhs, &nlp1, &c_b1034, &vt[nlf + vt_dim1], ldu, &rwork[(nlp1 * *nrhs << 1) + 1], &nlp1, &c_b328, &rwork[ 1], &nlp1); j = nlp1 * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nlf + nlp1 - 1; for (jrow = nlf; jrow <= i__3; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L220: */ } /* L230: */ } dgemm_("T", "N", &nlp1, nrhs, &nlp1, &c_b1034, &vt[nlf + vt_dim1], ldu, &rwork[(nlp1 * *nrhs << 1) + 1], &nlp1, &c_b328, &rwork[ nlp1 * *nrhs + 1], &nlp1); jreal = 0; jimag = nlp1 * *nrhs; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nlf + nlp1 - 1; for (jrow = nlf; jrow <= i__3; ++jrow) { ++jreal; ++jimag; i__4 = jrow + jcol * bx_dim1; i__5 = jreal; i__6 = jimag; z__1.r = rwork[i__5], z__1.i = rwork[i__6]; bx[i__4].r = z__1.r, bx[i__4].i = z__1.i; /* L240: */ } /* L250: */ } /* Since B and BX are complex, the following call to DGEMM is performed in two steps (real and imaginary parts). CALL DGEMM( 'T', 'N', NRP1, NRHS, NRP1, ONE, VT( NRF, 1 ), LDU, $ B( NRF, 1 ), LDB, ZERO, BX( NRF, 1 ), LDBX ) */ j = nrp1 * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nrf + nrp1 - 1; for (jrow = nrf; jrow <= i__3; ++jrow) { ++j; i__4 = jrow + jcol * b_dim1; rwork[j] = b[i__4].r; /* L260: */ } /* L270: */ } dgemm_("T", "N", &nrp1, nrhs, &nrp1, &c_b1034, &vt[nrf + vt_dim1], ldu, &rwork[(nrp1 * *nrhs << 1) + 1], &nrp1, &c_b328, &rwork[ 1], &nrp1); j = nrp1 * *nrhs << 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nrf + nrp1 - 1; for (jrow = nrf; jrow <= i__3; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L280: */ } /* L290: */ } dgemm_("T", "N", &nrp1, nrhs, &nrp1, &c_b1034, &vt[nrf + vt_dim1], ldu, &rwork[(nrp1 * *nrhs << 1) + 1], &nrp1, &c_b328, &rwork[ nrp1 * *nrhs + 1], &nrp1); jreal = 0; jimag = nrp1 * *nrhs; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = nrf + nrp1 - 1; for (jrow = nrf; jrow <= i__3; ++jrow) { ++jreal; ++jimag; i__4 = jrow + jcol * bx_dim1; i__5 = jreal; i__6 = jimag; z__1.r = rwork[i__5], z__1.i = rwork[i__6]; bx[i__4].r = z__1.r, bx[i__4].i = z__1.i; /* L300: */ } /* L310: */ } /* L320: */ } L330: return 0; /* End of ZLALSA */ } /* zlalsa_ */ /* Subroutine */ int zlalsd_(char *uplo, integer *smlsiz, integer *n, integer *nrhs, doublereal *d__, doublereal *e, doublecomplex *b, integer *ldb, doublereal *rcond, integer *rank, doublecomplex *work, doublereal * rwork, integer *iwork, integer *info) { /* System generated locals */ integer b_dim1, b_offset, i__1, i__2, i__3, i__4, i__5, i__6; doublereal d__1; doublecomplex z__1; /* Builtin functions */ double d_imag(doublecomplex *), log(doublereal), d_sign(doublereal *, doublereal *); /* Local variables */ static integer c__, i__, j, k; static doublereal r__; static integer s, u, z__; static doublereal cs; static integer bx; static doublereal sn; static integer st, vt, nm1, st1; static doublereal eps; static integer iwk; static doublereal tol; static integer difl, difr; static doublereal rcnd; static integer jcol, irwb, perm, nsub, nlvl, sqre, bxst, jrow, irwu, jimag; extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *); static integer jreal, irwib, poles, sizei, irwrb, nsize; extern /* Subroutine */ int zdrot_(integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, doublereal *), zcopy_( integer *, doublecomplex *, integer *, doublecomplex *, integer *) ; static integer irwvt, icmpq1, icmpq2; extern /* Subroutine */ int dlasda_(integer *, integer *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *, integer *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *), dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *); extern integer idamax_(integer *, doublereal *, integer *); extern /* Subroutine */ int dlasdq_(char *, integer *, integer *, integer *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *), dlaset_(char *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *), dlartg_(doublereal *, doublereal *, doublereal *, doublereal *, doublereal *), xerbla_(char *, integer *); static integer givcol; extern doublereal dlanst_(char *, integer *, doublereal *, doublereal *); extern /* Subroutine */ int zlalsa_(integer *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *, integer *, integer *, doublereal *, doublereal *, doublereal *, doublereal *, integer *, integer *), zlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublecomplex *, integer *, integer *), dlasrt_(char *, integer *, doublereal *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static doublereal orgnrm; static integer givnum, givptr, nrwork, irwwrk, smlszp; /* -- LAPACK routine (version 3.2.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- June 2010 Purpose ======= ZLALSD uses the singular value decomposition of A to solve the least squares problem of finding X to minimize the Euclidean norm of each column of A*X-B, where A is N-by-N upper bidiagonal, and X and B are N-by-NRHS. The solution X overwrites B. The singular values of A smaller than RCOND times the largest singular value are treated as zero in solving the least squares problem; in this case a minimum norm solution is returned. The actual singular values are returned in D in ascending order. This code makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray XMP, Cray YMP, Cray C 90, or Cray 2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Arguments ========= UPLO (input) CHARACTER*1 = 'U': D and E define an upper bidiagonal matrix. = 'L': D and E define a lower bidiagonal matrix. SMLSIZ (input) INTEGER The maximum size of the subproblems at the bottom of the computation tree. N (input) INTEGER The dimension of the bidiagonal matrix. N >= 0. NRHS (input) INTEGER The number of columns of B. NRHS must be at least 1. D (input/output) DOUBLE PRECISION array, dimension (N) On entry D contains the main diagonal of the bidiagonal matrix. On exit, if INFO = 0, D contains its singular values. E (input/output) DOUBLE PRECISION array, dimension (N-1) Contains the super-diagonal entries of the bidiagonal matrix. On exit, E has been destroyed. B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) On input, B contains the right hand sides of the least squares problem. On output, B contains the solution X. LDB (input) INTEGER The leading dimension of B in the calling subprogram. LDB must be at least max(1,N). RCOND (input) DOUBLE PRECISION The singular values of A less than or equal to RCOND times the largest singular value are treated as zero in solving the least squares problem. If RCOND is negative, machine precision is used instead. For example, if diag(S)*X=B were the least squares problem, where diag(S) is a diagonal matrix of singular values, the solution would be X(i) = B(i) / S(i) if S(i) is greater than RCOND*max(S), and X(i) = 0 if S(i) is less than or equal to RCOND*max(S). RANK (output) INTEGER The number of singular values of A greater than RCOND times the largest singular value. WORK (workspace) COMPLEX*16 array, dimension at least (N * NRHS). RWORK (workspace) DOUBLE PRECISION array, dimension at least (9*N + 2*N*SMLSIZ + 8*N*NLVL + 3*SMLSIZ*NRHS + MAX( (SMLSIZ+1)**2, N*(1+NRHS) + 2*NRHS ), where NLVL = MAX( 0, INT( LOG_2( MIN( M,N )/(SMLSIZ+1) ) ) + 1 ) IWORK (workspace) INTEGER array, dimension at least (3*N*NLVL + 11*N). INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: The algorithm failed to compute a singular value while working on the submatrix lying in rows and columns INFO/(N+1) through MOD(INFO,N+1). Further Details =============== Based on contributions by Ming Gu and Ren-Cang Li, Computer Science Division, University of California at Berkeley, USA Osni Marques, LBNL/NERSC, USA ===================================================================== Test the input parameters. */ /* Parameter adjustments */ --d__; --e; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; --work; --rwork; --iwork; /* Function Body */ *info = 0; if (*n < 0) { *info = -3; } else if (*nrhs < 1) { *info = -4; } else if (*ldb < 1 || *ldb < *n) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLALSD", &i__1); return 0; } eps = EPSILON; /* Set up the tolerance. */ if (*rcond <= 0. || *rcond >= 1.) { rcnd = eps; } else { rcnd = *rcond; } *rank = 0; /* Quick return if possible. */ if (*n == 0) { return 0; } else if (*n == 1) { if (d__[1] == 0.) { zlaset_("A", &c__1, nrhs, &c_b56, &c_b56, &b[b_offset], ldb); } else { *rank = 1; zlascl_("G", &c__0, &c__0, &d__[1], &c_b1034, &c__1, nrhs, &b[ b_offset], ldb, info); d__[1] = abs(d__[1]); } return 0; } /* Rotate the matrix if it is lower bidiagonal. */ if (*(unsigned char *)uplo == 'L') { i__1 = *n - 1; for (i__ = 1; i__ <= i__1; ++i__) { dlartg_(&d__[i__], &e[i__], &cs, &sn, &r__); d__[i__] = r__; e[i__] = sn * d__[i__ + 1]; d__[i__ + 1] = cs * d__[i__ + 1]; if (*nrhs == 1) { zdrot_(&c__1, &b[i__ + b_dim1], &c__1, &b[i__ + 1 + b_dim1], & c__1, &cs, &sn); } else { rwork[(i__ << 1) - 1] = cs; rwork[i__ * 2] = sn; } /* L10: */ } if (*nrhs > 1) { i__1 = *nrhs; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = *n - 1; for (j = 1; j <= i__2; ++j) { cs = rwork[(j << 1) - 1]; sn = rwork[j * 2]; zdrot_(&c__1, &b[j + i__ * b_dim1], &c__1, &b[j + 1 + i__ * b_dim1], &c__1, &cs, &sn); /* L20: */ } /* L30: */ } } } /* Scale. */ nm1 = *n - 1; orgnrm = dlanst_("M", n, &d__[1], &e[1]); if (orgnrm == 0.) { zlaset_("A", n, nrhs, &c_b56, &c_b56, &b[b_offset], ldb); return 0; } dlascl_("G", &c__0, &c__0, &orgnrm, &c_b1034, n, &c__1, &d__[1], n, info); dlascl_("G", &c__0, &c__0, &orgnrm, &c_b1034, &nm1, &c__1, &e[1], &nm1, info); /* If N is smaller than the minimum divide size SMLSIZ, then solve the problem with another solver. */ if (*n <= *smlsiz) { irwu = 1; irwvt = irwu + *n * *n; irwwrk = irwvt + *n * *n; irwrb = irwwrk; irwib = irwrb + *n * *nrhs; irwb = irwib + *n * *nrhs; dlaset_("A", n, n, &c_b328, &c_b1034, &rwork[irwu], n); dlaset_("A", n, n, &c_b328, &c_b1034, &rwork[irwvt], n); dlasdq_("U", &c__0, n, n, n, &c__0, &d__[1], &e[1], &rwork[irwvt], n, &rwork[irwu], n, &rwork[irwwrk], &c__1, &rwork[irwwrk], info); if (*info != 0) { return 0; } /* In the real version, B is passed to DLASDQ and multiplied internally by Q'. Here B is complex and that product is computed below in two steps (real and imaginary parts). */ j = irwb - 1; i__1 = *nrhs; for (jcol = 1; jcol <= i__1; ++jcol) { i__2 = *n; for (jrow = 1; jrow <= i__2; ++jrow) { ++j; i__3 = jrow + jcol * b_dim1; rwork[j] = b[i__3].r; /* L40: */ } /* L50: */ } dgemm_("T", "N", n, nrhs, n, &c_b1034, &rwork[irwu], n, &rwork[irwb], n, &c_b328, &rwork[irwrb], n); j = irwb - 1; i__1 = *nrhs; for (jcol = 1; jcol <= i__1; ++jcol) { i__2 = *n; for (jrow = 1; jrow <= i__2; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L60: */ } /* L70: */ } dgemm_("T", "N", n, nrhs, n, &c_b1034, &rwork[irwu], n, &rwork[irwb], n, &c_b328, &rwork[irwib], n); jreal = irwrb - 1; jimag = irwib - 1; i__1 = *nrhs; for (jcol = 1; jcol <= i__1; ++jcol) { i__2 = *n; for (jrow = 1; jrow <= i__2; ++jrow) { ++jreal; ++jimag; i__3 = jrow + jcol * b_dim1; i__4 = jreal; i__5 = jimag; z__1.r = rwork[i__4], z__1.i = rwork[i__5]; b[i__3].r = z__1.r, b[i__3].i = z__1.i; /* L80: */ } /* L90: */ } tol = rcnd * (d__1 = d__[idamax_(n, &d__[1], &c__1)], abs(d__1)); i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { if (d__[i__] <= tol) { zlaset_("A", &c__1, nrhs, &c_b56, &c_b56, &b[i__ + b_dim1], ldb); } else { zlascl_("G", &c__0, &c__0, &d__[i__], &c_b1034, &c__1, nrhs, & b[i__ + b_dim1], ldb, info); ++(*rank); } /* L100: */ } /* Since B is complex, the following call to DGEMM is performed in two steps (real and imaginary parts). That is for V * B (in the real version of the code V' is stored in WORK). CALL DGEMM( 'T', 'N', N, NRHS, N, ONE, WORK, N, B, LDB, ZERO, $ WORK( NWORK ), N ) */ j = irwb - 1; i__1 = *nrhs; for (jcol = 1; jcol <= i__1; ++jcol) { i__2 = *n; for (jrow = 1; jrow <= i__2; ++jrow) { ++j; i__3 = jrow + jcol * b_dim1; rwork[j] = b[i__3].r; /* L110: */ } /* L120: */ } dgemm_("T", "N", n, nrhs, n, &c_b1034, &rwork[irwvt], n, &rwork[irwb], n, &c_b328, &rwork[irwrb], n); j = irwb - 1; i__1 = *nrhs; for (jcol = 1; jcol <= i__1; ++jcol) { i__2 = *n; for (jrow = 1; jrow <= i__2; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L130: */ } /* L140: */ } dgemm_("T", "N", n, nrhs, n, &c_b1034, &rwork[irwvt], n, &rwork[irwb], n, &c_b328, &rwork[irwib], n); jreal = irwrb - 1; jimag = irwib - 1; i__1 = *nrhs; for (jcol = 1; jcol <= i__1; ++jcol) { i__2 = *n; for (jrow = 1; jrow <= i__2; ++jrow) { ++jreal; ++jimag; i__3 = jrow + jcol * b_dim1; i__4 = jreal; i__5 = jimag; z__1.r = rwork[i__4], z__1.i = rwork[i__5]; b[i__3].r = z__1.r, b[i__3].i = z__1.i; /* L150: */ } /* L160: */ } /* Unscale. */ dlascl_("G", &c__0, &c__0, &c_b1034, &orgnrm, n, &c__1, &d__[1], n, info); dlasrt_("D", n, &d__[1], info); zlascl_("G", &c__0, &c__0, &orgnrm, &c_b1034, n, nrhs, &b[b_offset], ldb, info); return 0; } /* Book-keeping and setting up some constants. */ nlvl = (integer) (log((doublereal) (*n) / (doublereal) (*smlsiz + 1)) / log(2.)) + 1; smlszp = *smlsiz + 1; u = 1; vt = *smlsiz * *n + 1; difl = vt + smlszp * *n; difr = difl + nlvl * *n; z__ = difr + (nlvl * *n << 1); c__ = z__ + nlvl * *n; s = c__ + *n; poles = s + *n; givnum = poles + (nlvl << 1) * *n; nrwork = givnum + (nlvl << 1) * *n; bx = 1; irwrb = nrwork; irwib = irwrb + *smlsiz * *nrhs; irwb = irwib + *smlsiz * *nrhs; sizei = *n + 1; k = sizei + *n; givptr = k + *n; perm = givptr + *n; givcol = perm + nlvl * *n; iwk = givcol + (nlvl * *n << 1); st = 1; sqre = 0; icmpq1 = 1; icmpq2 = 0; nsub = 0; i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { if ((d__1 = d__[i__], abs(d__1)) < eps) { d__[i__] = d_sign(&eps, &d__[i__]); } /* L170: */ } i__1 = nm1; for (i__ = 1; i__ <= i__1; ++i__) { if ((d__1 = e[i__], abs(d__1)) < eps || i__ == nm1) { ++nsub; iwork[nsub] = st; /* Subproblem found. First determine its size and then apply divide and conquer on it. */ if (i__ < nm1) { /* A subproblem with E(I) small for I < NM1. */ nsize = i__ - st + 1; iwork[sizei + nsub - 1] = nsize; } else if ((d__1 = e[i__], abs(d__1)) >= eps) { /* A subproblem with E(NM1) not too small but I = NM1. */ nsize = *n - st + 1; iwork[sizei + nsub - 1] = nsize; } else { /* A subproblem with E(NM1) small. This implies an 1-by-1 subproblem at D(N), which is not solved explicitly. */ nsize = i__ - st + 1; iwork[sizei + nsub - 1] = nsize; ++nsub; iwork[nsub] = *n; iwork[sizei + nsub - 1] = 1; zcopy_(nrhs, &b[*n + b_dim1], ldb, &work[bx + nm1], n); } st1 = st - 1; if (nsize == 1) { /* This is a 1-by-1 subproblem and is not solved explicitly. */ zcopy_(nrhs, &b[st + b_dim1], ldb, &work[bx + st1], n); } else if (nsize <= *smlsiz) { /* This is a small subproblem and is solved by DLASDQ. */ dlaset_("A", &nsize, &nsize, &c_b328, &c_b1034, &rwork[vt + st1], n); dlaset_("A", &nsize, &nsize, &c_b328, &c_b1034, &rwork[u + st1], n); dlasdq_("U", &c__0, &nsize, &nsize, &nsize, &c__0, &d__[st], & e[st], &rwork[vt + st1], n, &rwork[u + st1], n, & rwork[nrwork], &c__1, &rwork[nrwork], info) ; if (*info != 0) { return 0; } /* In the real version, B is passed to DLASDQ and multiplied internally by Q'. Here B is complex and that product is computed below in two steps (real and imaginary parts). */ j = irwb - 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = st + nsize - 1; for (jrow = st; jrow <= i__3; ++jrow) { ++j; i__4 = jrow + jcol * b_dim1; rwork[j] = b[i__4].r; /* L180: */ } /* L190: */ } dgemm_("T", "N", &nsize, nrhs, &nsize, &c_b1034, &rwork[u + st1], n, &rwork[irwb], &nsize, &c_b328, &rwork[irwrb], &nsize); j = irwb - 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = st + nsize - 1; for (jrow = st; jrow <= i__3; ++jrow) { ++j; rwork[j] = d_imag(&b[jrow + jcol * b_dim1]); /* L200: */ } /* L210: */ } dgemm_("T", "N", &nsize, nrhs, &nsize, &c_b1034, &rwork[u + st1], n, &rwork[irwb], &nsize, &c_b328, &rwork[irwib], &nsize); jreal = irwrb - 1; jimag = irwib - 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = st + nsize - 1; for (jrow = st; jrow <= i__3; ++jrow) { ++jreal; ++jimag; i__4 = jrow + jcol * b_dim1; i__5 = jreal; i__6 = jimag; z__1.r = rwork[i__5], z__1.i = rwork[i__6]; b[i__4].r = z__1.r, b[i__4].i = z__1.i; /* L220: */ } /* L230: */ } zlacpy_("A", &nsize, nrhs, &b[st + b_dim1], ldb, &work[bx + st1], n); } else { /* A large problem. Solve it using divide and conquer. */ dlasda_(&icmpq1, smlsiz, &nsize, &sqre, &d__[st], &e[st], & rwork[u + st1], n, &rwork[vt + st1], &iwork[k + st1], &rwork[difl + st1], &rwork[difr + st1], &rwork[z__ + st1], &rwork[poles + st1], &iwork[givptr + st1], & iwork[givcol + st1], n, &iwork[perm + st1], &rwork[ givnum + st1], &rwork[c__ + st1], &rwork[s + st1], & rwork[nrwork], &iwork[iwk], info); if (*info != 0) { return 0; } bxst = bx + st1; zlalsa_(&icmpq2, smlsiz, &nsize, nrhs, &b[st + b_dim1], ldb, & work[bxst], n, &rwork[u + st1], n, &rwork[vt + st1], & iwork[k + st1], &rwork[difl + st1], &rwork[difr + st1] , &rwork[z__ + st1], &rwork[poles + st1], &iwork[ givptr + st1], &iwork[givcol + st1], n, &iwork[perm + st1], &rwork[givnum + st1], &rwork[c__ + st1], &rwork[ s + st1], &rwork[nrwork], &iwork[iwk], info); if (*info != 0) { return 0; } } st = i__ + 1; } /* L240: */ } /* Apply the singular values and treat the tiny ones as zero. */ tol = rcnd * (d__1 = d__[idamax_(n, &d__[1], &c__1)], abs(d__1)); i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { /* Some of the elements in D can be negative because 1-by-1 subproblems were not solved explicitly. */ if ((d__1 = d__[i__], abs(d__1)) <= tol) { zlaset_("A", &c__1, nrhs, &c_b56, &c_b56, &work[bx + i__ - 1], n); } else { ++(*rank); zlascl_("G", &c__0, &c__0, &d__[i__], &c_b1034, &c__1, nrhs, & work[bx + i__ - 1], n, info); } d__[i__] = (d__1 = d__[i__], abs(d__1)); /* L250: */ } /* Now apply back the right singular vectors. */ icmpq2 = 1; i__1 = nsub; for (i__ = 1; i__ <= i__1; ++i__) { st = iwork[i__]; st1 = st - 1; nsize = iwork[sizei + i__ - 1]; bxst = bx + st1; if (nsize == 1) { zcopy_(nrhs, &work[bxst], n, &b[st + b_dim1], ldb); } else if (nsize <= *smlsiz) { /* Since B and BX are complex, the following call to DGEMM is performed in two steps (real and imaginary parts). CALL DGEMM( 'T', 'N', NSIZE, NRHS, NSIZE, ONE, $ RWORK( VT+ST1 ), N, RWORK( BXST ), N, ZERO, $ B( ST, 1 ), LDB ) */ j = bxst - *n - 1; jreal = irwb - 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { j += *n; i__3 = nsize; for (jrow = 1; jrow <= i__3; ++jrow) { ++jreal; i__4 = j + jrow; rwork[jreal] = work[i__4].r; /* L260: */ } /* L270: */ } dgemm_("T", "N", &nsize, nrhs, &nsize, &c_b1034, &rwork[vt + st1], n, &rwork[irwb], &nsize, &c_b328, &rwork[irwrb], &nsize); j = bxst - *n - 1; jimag = irwb - 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { j += *n; i__3 = nsize; for (jrow = 1; jrow <= i__3; ++jrow) { ++jimag; rwork[jimag] = d_imag(&work[j + jrow]); /* L280: */ } /* L290: */ } dgemm_("T", "N", &nsize, nrhs, &nsize, &c_b1034, &rwork[vt + st1], n, &rwork[irwb], &nsize, &c_b328, &rwork[irwib], &nsize); jreal = irwrb - 1; jimag = irwib - 1; i__2 = *nrhs; for (jcol = 1; jcol <= i__2; ++jcol) { i__3 = st + nsize - 1; for (jrow = st; jrow <= i__3; ++jrow) { ++jreal; ++jimag; i__4 = jrow + jcol * b_dim1; i__5 = jreal; i__6 = jimag; z__1.r = rwork[i__5], z__1.i = rwork[i__6]; b[i__4].r = z__1.r, b[i__4].i = z__1.i; /* L300: */ } /* L310: */ } } else { zlalsa_(&icmpq2, smlsiz, &nsize, nrhs, &work[bxst], n, &b[st + b_dim1], ldb, &rwork[u + st1], n, &rwork[vt + st1], & iwork[k + st1], &rwork[difl + st1], &rwork[difr + st1], & rwork[z__ + st1], &rwork[poles + st1], &iwork[givptr + st1], &iwork[givcol + st1], n, &iwork[perm + st1], &rwork[ givnum + st1], &rwork[c__ + st1], &rwork[s + st1], &rwork[ nrwork], &iwork[iwk], info); if (*info != 0) { return 0; } } /* L320: */ } /* Unscale and sort the singular values. */ dlascl_("G", &c__0, &c__0, &c_b1034, &orgnrm, n, &c__1, &d__[1], n, info); dlasrt_("D", n, &d__[1], info); zlascl_("G", &c__0, &c__0, &orgnrm, &c_b1034, n, nrhs, &b[b_offset], ldb, info); return 0; /* End of ZLALSD */ } /* zlalsd_ */ doublereal zlange_(char *norm, integer *m, integer *n, doublecomplex *a, integer *lda, doublereal *work) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; doublereal ret_val, d__1, d__2; /* Builtin functions */ double z_abs(doublecomplex *), sqrt(doublereal); /* Local variables */ static integer i__, j; static doublereal sum, scale; extern logical lsame_(char *, char *); static doublereal value; extern /* Subroutine */ int zlassq_(integer *, doublecomplex *, integer *, doublereal *, doublereal *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLANGE returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex matrix A. Description =========== ZLANGE returns the value ZLANGE = ( max(abs(A(i,j))), NORM = 'M' or 'm' ( ( norm1(A), NORM = '1', 'O' or 'o' ( ( normI(A), NORM = 'I' or 'i' ( ( normF(A), NORM = 'F', 'f', 'E' or 'e' where norm1 denotes the one norm of a matrix (maximum column sum), normI denotes the infinity norm of a matrix (maximum row sum) and normF denotes the Frobenius norm of a matrix (square root of sum of squares). Note that max(abs(A(i,j))) is not a consistent matrix norm. Arguments ========= NORM (input) CHARACTER*1 Specifies the value to be returned in ZLANGE as described above. M (input) INTEGER The number of rows of the matrix A. M >= 0. When M = 0, ZLANGE is set to zero. N (input) INTEGER The number of columns of the matrix A. N >= 0. When N = 0, ZLANGE is set to zero. A (input) COMPLEX*16 array, dimension (LDA,N) The m by n matrix A. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(M,1). WORK (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)), where LWORK >= M when NORM = 'I'; otherwise, WORK is not referenced. ===================================================================== */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --work; /* Function Body */ if (min(*m,*n) == 0) { value = 0.; } else if (lsame_(norm, "M")) { /* Find max(abs(A(i,j))). */ value = 0.; i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { /* Computing MAX */ d__1 = value, d__2 = z_abs(&a[i__ + j * a_dim1]); value = max(d__1,d__2); /* L10: */ } /* L20: */ } } else if (lsame_(norm, "O") || *(unsigned char *) norm == '1') { /* Find norm1(A). */ value = 0.; i__1 = *n; for (j = 1; j <= i__1; ++j) { sum = 0.; i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { sum += z_abs(&a[i__ + j * a_dim1]); /* L30: */ } value = max(value,sum); /* L40: */ } } else if (lsame_(norm, "I")) { /* Find normI(A). */ i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { work[i__] = 0.; /* L50: */ } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { work[i__] += z_abs(&a[i__ + j * a_dim1]); /* L60: */ } /* L70: */ } value = 0.; i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { /* Computing MAX */ d__1 = value, d__2 = work[i__]; value = max(d__1,d__2); /* L80: */ } } else if (lsame_(norm, "F") || lsame_(norm, "E")) { /* Find normF(A). */ scale = 0.; sum = 1.; i__1 = *n; for (j = 1; j <= i__1; ++j) { zlassq_(m, &a[j * a_dim1 + 1], &c__1, &scale, &sum); /* L90: */ } value = scale * sqrt(sum); } ret_val = value; return ret_val; /* End of ZLANGE */ } /* zlange_ */ doublereal zlanhe_(char *norm, char *uplo, integer *n, doublecomplex *a, integer *lda, doublereal *work) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; doublereal ret_val, d__1, d__2, d__3; /* Builtin functions */ double z_abs(doublecomplex *), sqrt(doublereal); /* Local variables */ static integer i__, j; static doublereal sum, absa, scale; extern logical lsame_(char *, char *); static doublereal value; extern /* Subroutine */ int zlassq_(integer *, doublecomplex *, integer *, doublereal *, doublereal *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLANHE returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex hermitian matrix A. Description =========== ZLANHE returns the value ZLANHE = ( max(abs(A(i,j))), NORM = 'M' or 'm' ( ( norm1(A), NORM = '1', 'O' or 'o' ( ( normI(A), NORM = 'I' or 'i' ( ( normF(A), NORM = 'F', 'f', 'E' or 'e' where norm1 denotes the one norm of a matrix (maximum column sum), normI denotes the infinity norm of a matrix (maximum row sum) and normF denotes the Frobenius norm of a matrix (square root of sum of squares). Note that max(abs(A(i,j))) is not a consistent matrix norm. Arguments ========= NORM (input) CHARACTER*1 Specifies the value to be returned in ZLANHE as described above. UPLO (input) CHARACTER*1 Specifies whether the upper or lower triangular part of the hermitian matrix A is to be referenced. = 'U': Upper triangular part of A is referenced = 'L': Lower triangular part of A is referenced N (input) INTEGER The order of the matrix A. N >= 0. When N = 0, ZLANHE is set to zero. A (input) COMPLEX*16 array, dimension (LDA,N) The hermitian matrix A. If UPLO = 'U', the leading n by n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. Note that the imaginary parts of the diagonal elements need not be set and are assumed to be zero. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(N,1). WORK (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)), where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise, WORK is not referenced. ===================================================================== */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --work; /* Function Body */ if (*n == 0) { value = 0.; } else if (lsame_(norm, "M")) { /* Find max(abs(A(i,j))). */ value = 0.; if (lsame_(uplo, "U")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { /* Computing MAX */ d__1 = value, d__2 = z_abs(&a[i__ + j * a_dim1]); value = max(d__1,d__2); /* L10: */ } /* Computing MAX */ i__2 = j + j * a_dim1; d__2 = value, d__3 = (d__1 = a[i__2].r, abs(d__1)); value = max(d__2,d__3); /* L20: */ } } else { i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__2 = j + j * a_dim1; d__2 = value, d__3 = (d__1 = a[i__2].r, abs(d__1)); value = max(d__2,d__3); i__2 = *n; for (i__ = j + 1; i__ <= i__2; ++i__) { /* Computing MAX */ d__1 = value, d__2 = z_abs(&a[i__ + j * a_dim1]); value = max(d__1,d__2); /* L30: */ } /* L40: */ } } } else if (lsame_(norm, "I") || lsame_(norm, "O") || *(unsigned char *)norm == '1') { /* Find normI(A) ( = norm1(A), since A is hermitian). */ value = 0.; if (lsame_(uplo, "U")) { i__1 = *n; for (j = 1; j <= i__1; ++j) { sum = 0.; i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { absa = z_abs(&a[i__ + j * a_dim1]); sum += absa; work[i__] += absa; /* L50: */ } i__2 = j + j * a_dim1; work[j] = sum + (d__1 = a[i__2].r, abs(d__1)); /* L60: */ } i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { /* Computing MAX */ d__1 = value, d__2 = work[i__]; value = max(d__1,d__2); /* L70: */ } } else { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { work[i__] = 0.; /* L80: */ } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = j + j * a_dim1; sum = work[j] + (d__1 = a[i__2].r, abs(d__1)); i__2 = *n; for (i__ = j + 1; i__ <= i__2; ++i__) { absa = z_abs(&a[i__ + j * a_dim1]); sum += absa; work[i__] += absa; /* L90: */ } value = max(value,sum); /* L100: */ } } } else if (lsame_(norm, "F") || lsame_(norm, "E")) { /* Find normF(A). */ scale = 0.; sum = 1.; if (lsame_(uplo, "U")) { i__1 = *n; for (j = 2; j <= i__1; ++j) { i__2 = j - 1; zlassq_(&i__2, &a[j * a_dim1 + 1], &c__1, &scale, &sum); /* L110: */ } } else { i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { i__2 = *n - j; zlassq_(&i__2, &a[j + 1 + j * a_dim1], &c__1, &scale, &sum); /* L120: */ } } sum *= 2; i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * a_dim1; if (a[i__2].r != 0.) { i__2 = i__ + i__ * a_dim1; absa = (d__1 = a[i__2].r, abs(d__1)); if (scale < absa) { /* Computing 2nd power */ d__1 = scale / absa; sum = sum * (d__1 * d__1) + 1.; scale = absa; } else { /* Computing 2nd power */ d__1 = absa / scale; sum += d__1 * d__1; } } /* L130: */ } value = scale * sqrt(sum); } ret_val = value; return ret_val; /* End of ZLANHE */ } /* zlanhe_ */ /* Subroutine */ int zlaqr0_(logical *wantt, logical *wantz, integer *n, integer *ilo, integer *ihi, doublecomplex *h__, integer *ldh, doublecomplex *w, integer *iloz, integer *ihiz, doublecomplex *z__, integer *ldz, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1, d__2, d__3, d__4, d__5, d__6, d__7, d__8; doublecomplex z__1, z__2, z__3, z__4, z__5; /* Builtin functions */ double d_imag(doublecomplex *); void z_sqrt(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, k; static doublereal s; static doublecomplex aa, bb, cc, dd; static integer ld, nh, it, ks, kt, ku, kv, ls, ns, nw; static doublecomplex tr2, det; static integer inf, kdu, nho, nve, kwh, nsr, nwr, kwv, ndec, ndfl, kbot, nmin; static doublecomplex swap; static integer ktop; static doublecomplex zdum[1] /* was [1][1] */; static integer kacc22, itmax, nsmax, nwmax, kwtop; extern /* Subroutine */ int zlaqr3_(logical *, logical *, integer *, integer *, integer *, integer *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer * , doublecomplex *, integer *), zlaqr4_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *), zlaqr5_(logical *, logical *, integer *, integer *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *); static integer nibble; extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static char jbcmpz[2]; static doublecomplex rtdisc; static integer nwupbd; static logical sorted; extern /* Subroutine */ int zlahqr_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer lwkopt; /* -- LAPACK auxiliary routine (version 3.2) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. November 2006 Purpose ======= ZLAQR0 computes the eigenvalues of a Hessenberg matrix H and, optionally, the matrices T and Z from the Schur decomposition H = Z T Z**H, where T is an upper triangular matrix (the Schur form), and Z is the unitary matrix of Schur vectors. Optionally Z may be postmultiplied into an input unitary matrix Q so that this routine can give the Schur factorization of a matrix A which has been reduced to the Hessenberg form H by the unitary matrix Q: A = Q*H*Q**H = (QZ)*H*(QZ)**H. Arguments ========= WANTT (input) LOGICAL = .TRUE. : the full Schur form T is required; = .FALSE.: only eigenvalues are required. WANTZ (input) LOGICAL = .TRUE. : the matrix of Schur vectors Z is required; = .FALSE.: Schur vectors are not required. N (input) INTEGER The order of the matrix H. N .GE. 0. ILO (input) INTEGER IHI (input) INTEGER It is assumed that H is already upper triangular in rows and columns 1:ILO-1 and IHI+1:N and, if ILO.GT.1, H(ILO,ILO-1) is zero. ILO and IHI are normally set by a previous call to ZGEBAL, and then passed to ZGEHRD when the matrix output by ZGEBAL is reduced to Hessenberg form. Otherwise, ILO and IHI should be set to 1 and N, respectively. If N.GT.0, then 1.LE.ILO.LE.IHI.LE.N. If N = 0, then ILO = 1 and IHI = 0. H (input/output) COMPLEX*16 array, dimension (LDH,N) On entry, the upper Hessenberg matrix H. On exit, if INFO = 0 and WANTT is .TRUE., then H contains the upper triangular matrix T from the Schur decomposition (the Schur form). If INFO = 0 and WANT is .FALSE., then the contents of H are unspecified on exit. (The output value of H when INFO.GT.0 is given under the description of INFO below.) This subroutine may explicitly set H(i,j) = 0 for i.GT.j and j = 1, 2, ... ILO-1 or j = IHI+1, IHI+2, ... N. LDH (input) INTEGER The leading dimension of the array H. LDH .GE. max(1,N). W (output) COMPLEX*16 array, dimension (N) The computed eigenvalues of H(ILO:IHI,ILO:IHI) are stored in W(ILO:IHI). If WANTT is .TRUE., then the eigenvalues are stored in the same order as on the diagonal of the Schur form returned in H, with W(i) = H(i,i). Z (input/output) COMPLEX*16 array, dimension (LDZ,IHI) If WANTZ is .FALSE., then Z is not referenced. If WANTZ is .TRUE., then Z(ILO:IHI,ILOZ:IHIZ) is replaced by Z(ILO:IHI,ILOZ:IHIZ)*U where U is the orthogonal Schur factor of H(ILO:IHI,ILO:IHI). (The output value of Z when INFO.GT.0 is given under the description of INFO below.) LDZ (input) INTEGER The leading dimension of the array Z. if WANTZ is .TRUE. then LDZ.GE.MAX(1,IHIZ). Otherwize, LDZ.GE.1. WORK (workspace/output) COMPLEX*16 array, dimension LWORK On exit, if LWORK = -1, WORK(1) returns an estimate of the optimal value for LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK .GE. max(1,N) is sufficient, but LWORK typically as large as 6*N may be required for optimal performance. A workspace query to determine the optimal workspace size is recommended. If LWORK = -1, then ZLAQR0 does a workspace query. In this case, ZLAQR0 checks the input parameters and estimates the optimal workspace size for the given values of N, ILO and IHI. The estimate is returned in WORK(1). No error message related to LWORK is issued by XERBLA. Neither H nor Z are accessed. INFO (output) INTEGER = 0: successful exit .GT. 0: if INFO = i, ZLAQR0 failed to compute all of the eigenvalues. Elements 1:ilo-1 and i+1:n of WR and WI contain those eigenvalues which have been successfully computed. (Failures are rare.) If INFO .GT. 0 and WANT is .FALSE., then on exit, the remaining unconverged eigenvalues are the eigen- values of the upper Hessenberg matrix rows and columns ILO through INFO of the final, output value of H. If INFO .GT. 0 and WANTT is .TRUE., then on exit (*) (initial value of H)*U = U*(final value of H) where U is a unitary matrix. The final value of H is upper Hessenberg and triangular in rows and columns INFO+1 through IHI. If INFO .GT. 0 and WANTZ is .TRUE., then on exit (final value of Z(ILO:IHI,ILOZ:IHIZ) = (initial value of Z(ILO:IHI,ILOZ:IHIZ)*U where U is the unitary matrix in (*) (regard- less of the value of WANTT.) If INFO .GT. 0 and WANTZ is .FALSE., then Z is not accessed. ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ References: K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 Performance, SIAM Journal of Matrix Analysis, volume 23, pages 929--947, 2002. K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part II: Aggressive Early Deflation, SIAM Journal of Matrix Analysis, volume 23, pages 948--973, 2002. ================================================================ ==== Matrices of order NTINY or smaller must be processed by . ZLAHQR because of insufficient subdiagonal scratch space. . (This is a hard limit.) ==== ==== Exceptional deflation windows: try to cure rare . slow convergence by varying the size of the . deflation window after KEXNW iterations. ==== ==== Exceptional shifts: try to cure rare slow convergence . with ad-hoc exceptional shifts every KEXSH iterations. . ==== ==== The constant WILK1 is used to form the exceptional . shifts. ==== */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; --w; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --work; /* Function Body */ *info = 0; /* ==== Quick return for N = 0: nothing to do. ==== */ if (*n == 0) { work[1].r = 1., work[1].i = 0.; return 0; } if (*n <= 11) { /* ==== Tiny matrices must use ZLAHQR. ==== */ lwkopt = 1; if (*lwork != -1) { zlahqr_(wantt, wantz, n, ilo, ihi, &h__[h_offset], ldh, &w[1], iloz, ihiz, &z__[z_offset], ldz, info); } } else { /* ==== Use small bulge multi-shift QR with aggressive early . deflation on larger-than-tiny matrices. ==== ==== Hope for the best. ==== */ *info = 0; /* ==== Set up job flags for ILAENV. ==== */ if (*wantt) { *(unsigned char *)jbcmpz = 'S'; } else { *(unsigned char *)jbcmpz = 'E'; } if (*wantz) { *(unsigned char *)&jbcmpz[1] = 'V'; } else { *(unsigned char *)&jbcmpz[1] = 'N'; } /* ==== NWR = recommended deflation window size. At this . point, N .GT. NTINY = 11, so there is enough . subdiagonal workspace for NWR.GE.2 as required. . (In fact, there is enough subdiagonal space for . NWR.GE.3.) ==== */ nwr = ilaenv_(&c__13, "ZLAQR0", jbcmpz, n, ilo, ihi, lwork, (ftnlen)6, (ftnlen)2); nwr = max(2,nwr); /* Computing MIN */ i__1 = *ihi - *ilo + 1, i__2 = (*n - 1) / 3, i__1 = min(i__1,i__2); nwr = min(i__1,nwr); /* ==== NSR = recommended number of simultaneous shifts. . At this point N .GT. NTINY = 11, so there is at . enough subdiagonal workspace for NSR to be even . and greater than or equal to two as required. ==== */ nsr = ilaenv_(&c__15, "ZLAQR0", jbcmpz, n, ilo, ihi, lwork, (ftnlen)6, (ftnlen)2); /* Computing MIN */ i__1 = nsr, i__2 = (*n + 6) / 9, i__1 = min(i__1,i__2), i__2 = *ihi - *ilo; nsr = min(i__1,i__2); /* Computing MAX */ i__1 = 2, i__2 = nsr - nsr % 2; nsr = max(i__1,i__2); /* ==== Estimate optimal workspace ==== ==== Workspace query call to ZLAQR3 ==== */ i__1 = nwr + 1; zlaqr3_(wantt, wantz, n, ilo, ihi, &i__1, &h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &w[1], &h__[h_offset], ldh, n, &h__[h_offset], ldh, n, &h__[h_offset], ldh, &work[1], &c_n1); /* ==== Optimal workspace = MAX(ZLAQR5, ZLAQR3) ==== Computing MAX */ i__1 = nsr * 3 / 2, i__2 = (integer) work[1].r; lwkopt = max(i__1,i__2); /* ==== Quick return in case of workspace query. ==== */ if (*lwork == -1) { d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; return 0; } /* ==== ZLAHQR/ZLAQR0 crossover point ==== */ nmin = ilaenv_(&c__12, "ZLAQR0", jbcmpz, n, ilo, ihi, lwork, (ftnlen) 6, (ftnlen)2); nmin = max(11,nmin); /* ==== Nibble crossover point ==== */ nibble = ilaenv_(&c__14, "ZLAQR0", jbcmpz, n, ilo, ihi, lwork, ( ftnlen)6, (ftnlen)2); nibble = max(0,nibble); /* ==== Accumulate reflections during ttswp? Use block . 2-by-2 structure during matrix-matrix multiply? ==== */ kacc22 = ilaenv_(&c__16, "ZLAQR0", jbcmpz, n, ilo, ihi, lwork, ( ftnlen)6, (ftnlen)2); kacc22 = max(0,kacc22); kacc22 = min(2,kacc22); /* ==== NWMAX = the largest possible deflation window for . which there is sufficient workspace. ==== Computing MIN */ i__1 = (*n - 1) / 3, i__2 = *lwork / 2; nwmax = min(i__1,i__2); nw = nwmax; /* ==== NSMAX = the Largest number of simultaneous shifts . for which there is sufficient workspace. ==== Computing MIN */ i__1 = (*n + 6) / 9, i__2 = (*lwork << 1) / 3; nsmax = min(i__1,i__2); nsmax -= nsmax % 2; /* ==== NDFL: an iteration count restarted at deflation. ==== */ ndfl = 1; /* ==== ITMAX = iteration limit ==== Computing MAX */ i__1 = 10, i__2 = *ihi - *ilo + 1; itmax = max(i__1,i__2) * 30; /* ==== Last row and column in the active block ==== */ kbot = *ihi; /* ==== Main Loop ==== */ i__1 = itmax; for (it = 1; it <= i__1; ++it) { /* ==== Done when KBOT falls below ILO ==== */ if (kbot < *ilo) { goto L80; } /* ==== Locate active block ==== */ i__2 = *ilo + 1; for (k = kbot; k >= i__2; --k) { i__3 = k + (k - 1) * h_dim1; if (h__[i__3].r == 0. && h__[i__3].i == 0.) { goto L20; } /* L10: */ } k = *ilo; L20: ktop = k; /* ==== Select deflation window size: . Typical Case: . If possible and advisable, nibble the entire . active block. If not, use size MIN(NWR,NWMAX) . or MIN(NWR+1,NWMAX) depending upon which has . the smaller corresponding subdiagonal entry . (a heuristic). . . Exceptional Case: . If there have been no deflations in KEXNW or . more iterations, then vary the deflation window . size. At first, because, larger windows are, . in general, more powerful than smaller ones, . rapidly increase the window to the maximum possible. . Then, gradually reduce the window size. ==== */ nh = kbot - ktop + 1; nwupbd = min(nh,nwmax); if (ndfl < 5) { nw = min(nwupbd,nwr); } else { /* Computing MIN */ i__2 = nwupbd, i__3 = nw << 1; nw = min(i__2,i__3); } if (nw < nwmax) { if (nw >= nh - 1) { nw = nh; } else { kwtop = kbot - nw + 1; i__2 = kwtop + (kwtop - 1) * h_dim1; i__3 = kwtop - 1 + (kwtop - 2) * h_dim1; if ((d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[ kwtop + (kwtop - 1) * h_dim1]), abs(d__2)) > ( d__3 = h__[i__3].r, abs(d__3)) + (d__4 = d_imag(& h__[kwtop - 1 + (kwtop - 2) * h_dim1]), abs(d__4)) ) { ++nw; } } } if (ndfl < 5) { ndec = -1; } else if (ndec >= 0 || nw >= nwupbd) { ++ndec; if (nw - ndec < 2) { ndec = 0; } nw -= ndec; } /* ==== Aggressive early deflation: . split workspace under the subdiagonal into . - an nw-by-nw work array V in the lower . left-hand-corner, . - an NW-by-at-least-NW-but-more-is-better . (NW-by-NHO) horizontal work array along . the bottom edge, . - an at-least-NW-but-more-is-better (NHV-by-NW) . vertical work array along the left-hand-edge. . ==== */ kv = *n - nw + 1; kt = nw + 1; nho = *n - nw - 1 - kt + 1; kwv = nw + 2; nve = *n - nw - kwv + 1; /* ==== Aggressive early deflation ==== */ zlaqr3_(wantt, wantz, n, &ktop, &kbot, &nw, &h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &w[1], &h__[kv + h_dim1], ldh, &nho, &h__[kv + kt * h_dim1], ldh, &nve, & h__[kwv + h_dim1], ldh, &work[1], lwork); /* ==== Adjust KBOT accounting for new deflations. ==== */ kbot -= ld; /* ==== KS points to the shifts. ==== */ ks = kbot - ls + 1; /* ==== Skip an expensive QR sweep if there is a (partly . heuristic) reason to expect that many eigenvalues . will deflate without it. Here, the QR sweep is . skipped if many eigenvalues have just been deflated . or if the remaining active block is small. */ if (ld == 0 || ld * 100 <= nw * nibble && kbot - ktop + 1 > min( nmin,nwmax)) { /* ==== NS = nominal number of simultaneous shifts. . This may be lowered (slightly) if ZLAQR3 . did not provide that many shifts. ==== Computing MIN Computing MAX */ i__4 = 2, i__5 = kbot - ktop; i__2 = min(nsmax,nsr), i__3 = max(i__4,i__5); ns = min(i__2,i__3); ns -= ns % 2; /* ==== If there have been no deflations . in a multiple of KEXSH iterations, . then try exceptional shifts. . Otherwise use shifts provided by . ZLAQR3 above or from the eigenvalues . of a trailing principal submatrix. ==== */ if (ndfl % 6 == 0) { ks = kbot - ns + 1; i__2 = ks + 1; for (i__ = kbot; i__ >= i__2; i__ += -2) { i__3 = i__; i__4 = i__ + i__ * h_dim1; i__5 = i__ + (i__ - 1) * h_dim1; d__3 = ((d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[i__ + (i__ - 1) * h_dim1]), abs( d__2))) * .75; z__1.r = h__[i__4].r + d__3, z__1.i = h__[i__4].i; w[i__3].r = z__1.r, w[i__3].i = z__1.i; i__3 = i__ - 1; i__4 = i__; w[i__3].r = w[i__4].r, w[i__3].i = w[i__4].i; /* L30: */ } } else { /* ==== Got NS/2 or fewer shifts? Use ZLAQR4 or . ZLAHQR on a trailing principal submatrix to . get more. (Since NS.LE.NSMAX.LE.(N+6)/9, . there is enough space below the subdiagonal . to fit an NS-by-NS scratch array.) ==== */ if (kbot - ks + 1 <= ns / 2) { ks = kbot - ns + 1; kt = *n - ns + 1; zlacpy_("A", &ns, &ns, &h__[ks + ks * h_dim1], ldh, & h__[kt + h_dim1], ldh); if (ns > nmin) { zlaqr4_(&c_false, &c_false, &ns, &c__1, &ns, &h__[ kt + h_dim1], ldh, &w[ks], &c__1, &c__1, zdum, &c__1, &work[1], lwork, &inf); } else { zlahqr_(&c_false, &c_false, &ns, &c__1, &ns, &h__[ kt + h_dim1], ldh, &w[ks], &c__1, &c__1, zdum, &c__1, &inf); } ks += inf; /* ==== In case of a rare QR failure use . eigenvalues of the trailing 2-by-2 . principal submatrix. Scale to avoid . overflows, underflows and subnormals. . (The scale factor S can not be zero, . because H(KBOT,KBOT-1) is nonzero.) ==== */ if (ks >= kbot) { i__2 = kbot - 1 + (kbot - 1) * h_dim1; i__3 = kbot + (kbot - 1) * h_dim1; i__4 = kbot - 1 + kbot * h_dim1; i__5 = kbot + kbot * h_dim1; s = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[kbot - 1 + (kbot - 1) * h_dim1]), abs(d__2)) + ((d__3 = h__[i__3] .r, abs(d__3)) + (d__4 = d_imag(&h__[kbot + (kbot - 1) * h_dim1]), abs(d__4))) + (( d__5 = h__[i__4].r, abs(d__5)) + (d__6 = d_imag(&h__[kbot - 1 + kbot * h_dim1]), abs(d__6))) + ((d__7 = h__[i__5].r, abs( d__7)) + (d__8 = d_imag(&h__[kbot + kbot * h_dim1]), abs(d__8))); i__2 = kbot - 1 + (kbot - 1) * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; aa.r = z__1.r, aa.i = z__1.i; i__2 = kbot + (kbot - 1) * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; cc.r = z__1.r, cc.i = z__1.i; i__2 = kbot - 1 + kbot * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; bb.r = z__1.r, bb.i = z__1.i; i__2 = kbot + kbot * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; dd.r = z__1.r, dd.i = z__1.i; z__2.r = aa.r + dd.r, z__2.i = aa.i + dd.i; z__1.r = z__2.r / 2., z__1.i = z__2.i / 2.; tr2.r = z__1.r, tr2.i = z__1.i; z__3.r = aa.r - tr2.r, z__3.i = aa.i - tr2.i; z__4.r = dd.r - tr2.r, z__4.i = dd.i - tr2.i; z__2.r = z__3.r * z__4.r - z__3.i * z__4.i, z__2.i = z__3.r * z__4.i + z__3.i * z__4.r; z__5.r = bb.r * cc.r - bb.i * cc.i, z__5.i = bb.r * cc.i + bb.i * cc.r; z__1.r = z__2.r - z__5.r, z__1.i = z__2.i - z__5.i; det.r = z__1.r, det.i = z__1.i; z__2.r = -det.r, z__2.i = -det.i; z_sqrt(&z__1, &z__2); rtdisc.r = z__1.r, rtdisc.i = z__1.i; i__2 = kbot - 1; z__2.r = tr2.r + rtdisc.r, z__2.i = tr2.i + rtdisc.i; z__1.r = s * z__2.r, z__1.i = s * z__2.i; w[i__2].r = z__1.r, w[i__2].i = z__1.i; i__2 = kbot; z__2.r = tr2.r - rtdisc.r, z__2.i = tr2.i - rtdisc.i; z__1.r = s * z__2.r, z__1.i = s * z__2.i; w[i__2].r = z__1.r, w[i__2].i = z__1.i; ks = kbot - 1; } } if (kbot - ks + 1 > ns) { /* ==== Sort the shifts (Helps a little) ==== */ sorted = FALSE_; i__2 = ks + 1; for (k = kbot; k >= i__2; --k) { if (sorted) { goto L60; } sorted = TRUE_; i__3 = k - 1; for (i__ = ks; i__ <= i__3; ++i__) { i__4 = i__; i__5 = i__ + 1; if ((d__1 = w[i__4].r, abs(d__1)) + (d__2 = d_imag(&w[i__]), abs(d__2)) < (d__3 = w[i__5].r, abs(d__3)) + (d__4 = d_imag(&w[i__ + 1]), abs(d__4))) { sorted = FALSE_; i__4 = i__; swap.r = w[i__4].r, swap.i = w[i__4].i; i__4 = i__; i__5 = i__ + 1; w[i__4].r = w[i__5].r, w[i__4].i = w[i__5] .i; i__4 = i__ + 1; w[i__4].r = swap.r, w[i__4].i = swap.i; } /* L40: */ } /* L50: */ } L60: ; } } /* ==== If there are only two shifts, then use . only one. ==== */ if (kbot - ks + 1 == 2) { i__2 = kbot; i__3 = kbot + kbot * h_dim1; z__2.r = w[i__2].r - h__[i__3].r, z__2.i = w[i__2].i - h__[i__3].i; z__1.r = z__2.r, z__1.i = z__2.i; i__4 = kbot - 1; i__5 = kbot + kbot * h_dim1; z__4.r = w[i__4].r - h__[i__5].r, z__4.i = w[i__4].i - h__[i__5].i; z__3.r = z__4.r, z__3.i = z__4.i; if ((d__1 = z__1.r, abs(d__1)) + (d__2 = d_imag(&z__1), abs(d__2)) < (d__3 = z__3.r, abs(d__3)) + (d__4 = d_imag(&z__3), abs(d__4))) { i__2 = kbot - 1; i__3 = kbot; w[i__2].r = w[i__3].r, w[i__2].i = w[i__3].i; } else { i__2 = kbot; i__3 = kbot - 1; w[i__2].r = w[i__3].r, w[i__2].i = w[i__3].i; } } /* ==== Use up to NS of the the smallest magnatiude . shifts. If there aren't NS shifts available, . then use them all, possibly dropping one to . make the number of shifts even. ==== Computing MIN */ i__2 = ns, i__3 = kbot - ks + 1; ns = min(i__2,i__3); ns -= ns % 2; ks = kbot - ns + 1; /* ==== Small-bulge multi-shift QR sweep: . split workspace under the subdiagonal into . - a KDU-by-KDU work array U in the lower . left-hand-corner, . - a KDU-by-at-least-KDU-but-more-is-better . (KDU-by-NHo) horizontal work array WH along . the bottom edge, . - and an at-least-KDU-but-more-is-better-by-KDU . (NVE-by-KDU) vertical work WV arrow along . the left-hand-edge. ==== */ kdu = ns * 3 - 3; ku = *n - kdu + 1; kwh = kdu + 1; nho = *n - kdu - 3 - (kdu + 1) + 1; kwv = kdu + 4; nve = *n - kdu - kwv + 1; /* ==== Small-bulge multi-shift QR sweep ==== */ zlaqr5_(wantt, wantz, &kacc22, n, &ktop, &kbot, &ns, &w[ks], & h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, & work[1], &c__3, &h__[ku + h_dim1], ldh, &nve, &h__[ kwv + h_dim1], ldh, &nho, &h__[ku + kwh * h_dim1], ldh); } /* ==== Note progress (or the lack of it). ==== */ if (ld > 0) { ndfl = 1; } else { ++ndfl; } /* ==== End of main loop ==== L70: */ } /* ==== Iteration limit exceeded. Set INFO to show where . the problem occurred and exit. ==== */ *info = kbot; L80: ; } /* ==== Return the optimal value of LWORK. ==== */ d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; /* ==== End of ZLAQR0 ==== */ return 0; } /* zlaqr0_ */ /* Subroutine */ int zlaqr1_(integer *n, doublecomplex *h__, integer *ldh, doublecomplex *s1, doublecomplex *s2, doublecomplex *v) { /* System generated locals */ integer h_dim1, h_offset, i__1, i__2, i__3, i__4; doublereal d__1, d__2, d__3, d__4, d__5, d__6; doublecomplex z__1, z__2, z__3, z__4, z__5, z__6, z__7, z__8; /* Builtin functions */ double d_imag(doublecomplex *); /* Local variables */ static doublereal s; static doublecomplex h21s, h31s; /* -- LAPACK auxiliary routine (version 3.2) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. November 2006 Given a 2-by-2 or 3-by-3 matrix H, ZLAQR1 sets v to a scalar multiple of the first column of the product (*) K = (H - s1*I)*(H - s2*I) scaling to avoid overflows and most underflows. This is useful for starting double implicit shift bulges in the QR algorithm. N (input) integer Order of the matrix H. N must be either 2 or 3. H (input) COMPLEX*16 array of dimension (LDH,N) The 2-by-2 or 3-by-3 matrix H in (*). LDH (input) integer The leading dimension of H as declared in the calling procedure. LDH.GE.N S1 (input) COMPLEX*16 S2 S1 and S2 are the shifts defining K in (*) above. V (output) COMPLEX*16 array of dimension N A scalar multiple of the first column of the matrix K in (*). ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; --v; /* Function Body */ if (*n == 2) { i__1 = h_dim1 + 1; z__2.r = h__[i__1].r - s2->r, z__2.i = h__[i__1].i - s2->i; z__1.r = z__2.r, z__1.i = z__2.i; i__2 = h_dim1 + 2; s = (d__1 = z__1.r, abs(d__1)) + (d__2 = d_imag(&z__1), abs(d__2)) + ( (d__3 = h__[i__2].r, abs(d__3)) + (d__4 = d_imag(&h__[h_dim1 + 2]), abs(d__4))); if (s == 0.) { v[1].r = 0., v[1].i = 0.; v[2].r = 0., v[2].i = 0.; } else { i__1 = h_dim1 + 2; z__1.r = h__[i__1].r / s, z__1.i = h__[i__1].i / s; h21s.r = z__1.r, h21s.i = z__1.i; i__1 = (h_dim1 << 1) + 1; z__2.r = h21s.r * h__[i__1].r - h21s.i * h__[i__1].i, z__2.i = h21s.r * h__[i__1].i + h21s.i * h__[i__1].r; i__2 = h_dim1 + 1; z__4.r = h__[i__2].r - s1->r, z__4.i = h__[i__2].i - s1->i; i__3 = h_dim1 + 1; z__6.r = h__[i__3].r - s2->r, z__6.i = h__[i__3].i - s2->i; z__5.r = z__6.r / s, z__5.i = z__6.i / s; z__3.r = z__4.r * z__5.r - z__4.i * z__5.i, z__3.i = z__4.r * z__5.i + z__4.i * z__5.r; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; v[1].r = z__1.r, v[1].i = z__1.i; i__1 = h_dim1 + 1; i__2 = (h_dim1 << 1) + 2; z__4.r = h__[i__1].r + h__[i__2].r, z__4.i = h__[i__1].i + h__[ i__2].i; z__3.r = z__4.r - s1->r, z__3.i = z__4.i - s1->i; z__2.r = z__3.r - s2->r, z__2.i = z__3.i - s2->i; z__1.r = h21s.r * z__2.r - h21s.i * z__2.i, z__1.i = h21s.r * z__2.i + h21s.i * z__2.r; v[2].r = z__1.r, v[2].i = z__1.i; } } else { i__1 = h_dim1 + 1; z__2.r = h__[i__1].r - s2->r, z__2.i = h__[i__1].i - s2->i; z__1.r = z__2.r, z__1.i = z__2.i; i__2 = h_dim1 + 2; i__3 = h_dim1 + 3; s = (d__1 = z__1.r, abs(d__1)) + (d__2 = d_imag(&z__1), abs(d__2)) + ( (d__3 = h__[i__2].r, abs(d__3)) + (d__4 = d_imag(&h__[h_dim1 + 2]), abs(d__4))) + ((d__5 = h__[i__3].r, abs(d__5)) + (d__6 = d_imag(&h__[h_dim1 + 3]), abs(d__6))); if (s == 0.) { v[1].r = 0., v[1].i = 0.; v[2].r = 0., v[2].i = 0.; v[3].r = 0., v[3].i = 0.; } else { i__1 = h_dim1 + 2; z__1.r = h__[i__1].r / s, z__1.i = h__[i__1].i / s; h21s.r = z__1.r, h21s.i = z__1.i; i__1 = h_dim1 + 3; z__1.r = h__[i__1].r / s, z__1.i = h__[i__1].i / s; h31s.r = z__1.r, h31s.i = z__1.i; i__1 = h_dim1 + 1; z__4.r = h__[i__1].r - s1->r, z__4.i = h__[i__1].i - s1->i; i__2 = h_dim1 + 1; z__6.r = h__[i__2].r - s2->r, z__6.i = h__[i__2].i - s2->i; z__5.r = z__6.r / s, z__5.i = z__6.i / s; z__3.r = z__4.r * z__5.r - z__4.i * z__5.i, z__3.i = z__4.r * z__5.i + z__4.i * z__5.r; i__3 = (h_dim1 << 1) + 1; z__7.r = h__[i__3].r * h21s.r - h__[i__3].i * h21s.i, z__7.i = h__[i__3].r * h21s.i + h__[i__3].i * h21s.r; z__2.r = z__3.r + z__7.r, z__2.i = z__3.i + z__7.i; i__4 = h_dim1 * 3 + 1; z__8.r = h__[i__4].r * h31s.r - h__[i__4].i * h31s.i, z__8.i = h__[i__4].r * h31s.i + h__[i__4].i * h31s.r; z__1.r = z__2.r + z__8.r, z__1.i = z__2.i + z__8.i; v[1].r = z__1.r, v[1].i = z__1.i; i__1 = h_dim1 + 1; i__2 = (h_dim1 << 1) + 2; z__5.r = h__[i__1].r + h__[i__2].r, z__5.i = h__[i__1].i + h__[ i__2].i; z__4.r = z__5.r - s1->r, z__4.i = z__5.i - s1->i; z__3.r = z__4.r - s2->r, z__3.i = z__4.i - s2->i; z__2.r = h21s.r * z__3.r - h21s.i * z__3.i, z__2.i = h21s.r * z__3.i + h21s.i * z__3.r; i__3 = h_dim1 * 3 + 2; z__6.r = h__[i__3].r * h31s.r - h__[i__3].i * h31s.i, z__6.i = h__[i__3].r * h31s.i + h__[i__3].i * h31s.r; z__1.r = z__2.r + z__6.r, z__1.i = z__2.i + z__6.i; v[2].r = z__1.r, v[2].i = z__1.i; i__1 = h_dim1 + 1; i__2 = h_dim1 * 3 + 3; z__5.r = h__[i__1].r + h__[i__2].r, z__5.i = h__[i__1].i + h__[ i__2].i; z__4.r = z__5.r - s1->r, z__4.i = z__5.i - s1->i; z__3.r = z__4.r - s2->r, z__3.i = z__4.i - s2->i; z__2.r = h31s.r * z__3.r - h31s.i * z__3.i, z__2.i = h31s.r * z__3.i + h31s.i * z__3.r; i__3 = (h_dim1 << 1) + 3; z__6.r = h21s.r * h__[i__3].r - h21s.i * h__[i__3].i, z__6.i = h21s.r * h__[i__3].i + h21s.i * h__[i__3].r; z__1.r = z__2.r + z__6.r, z__1.i = z__2.i + z__6.i; v[3].r = z__1.r, v[3].i = z__1.i; } } return 0; } /* zlaqr1_ */ /* Subroutine */ int zlaqr2_(logical *wantt, logical *wantz, integer *n, integer *ktop, integer *kbot, integer *nw, doublecomplex *h__, integer *ldh, integer *iloz, integer *ihiz, doublecomplex *z__, integer *ldz, integer *ns, integer *nd, doublecomplex *sh, doublecomplex *v, integer *ldv, integer *nh, doublecomplex *t, integer *ldt, integer *nv, doublecomplex *wv, integer *ldwv, doublecomplex *work, integer *lwork) { /* System generated locals */ integer h_dim1, h_offset, t_dim1, t_offset, v_dim1, v_offset, wv_dim1, wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4; doublereal d__1, d__2, d__3, d__4, d__5, d__6; doublecomplex z__1, z__2; /* Builtin functions */ double d_imag(doublecomplex *); void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j; static doublecomplex s; static integer jw; static doublereal foo; static integer kln; static doublecomplex tau; static integer knt; static doublereal ulp; static integer lwk1, lwk2; static doublecomplex beta; static integer kcol, info, ifst, ilst, ltop, krow; extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); static integer infqr; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer kwtop; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), dlabad_(doublereal *, doublereal *); static doublereal safmin, safmax; extern /* Subroutine */ int zgehrd_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlahqr_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static doublereal smlnum; extern /* Subroutine */ int ztrexc_(char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, integer *, integer *); static integer lwkopt; extern /* Subroutine */ int zunmhr_(char *, char *, integer *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer * ); /* -- LAPACK auxiliary routine (version 3.2.1) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. -- April 2009 -- This subroutine is identical to ZLAQR3 except that it avoids recursion by calling ZLAHQR instead of ZLAQR4. ****************************************************************** Aggressive early deflation: This subroutine accepts as input an upper Hessenberg matrix H and performs an unitary similarity transformation designed to detect and deflate fully converged eigenvalues from a trailing principal submatrix. On output H has been over- written by a new Hessenberg matrix that is a perturbation of an unitary similarity transformation of H. It is to be hoped that the final version of H has many zero subdiagonal entries. ****************************************************************** WANTT (input) LOGICAL If .TRUE., then the Hessenberg matrix H is fully updated so that the triangular Schur factor may be computed (in cooperation with the calling subroutine). If .FALSE., then only enough of H is updated to preserve the eigenvalues. WANTZ (input) LOGICAL If .TRUE., then the unitary matrix Z is updated so so that the unitary Schur factor may be computed (in cooperation with the calling subroutine). If .FALSE., then Z is not referenced. N (input) INTEGER The order of the matrix H and (if WANTZ is .TRUE.) the order of the unitary matrix Z. KTOP (input) INTEGER It is assumed that either KTOP = 1 or H(KTOP,KTOP-1)=0. KBOT and KTOP together determine an isolated block along the diagonal of the Hessenberg matrix. KBOT (input) INTEGER It is assumed without a check that either KBOT = N or H(KBOT+1,KBOT)=0. KBOT and KTOP together determine an isolated block along the diagonal of the Hessenberg matrix. NW (input) INTEGER Deflation window size. 1 .LE. NW .LE. (KBOT-KTOP+1). H (input/output) COMPLEX*16 array, dimension (LDH,N) On input the initial N-by-N section of H stores the Hessenberg matrix undergoing aggressive early deflation. On output H has been transformed by a unitary similarity transformation, perturbed, and the returned to Hessenberg form that (it is to be hoped) has some zero subdiagonal entries. LDH (input) integer Leading dimension of H just as declared in the calling subroutine. N .LE. LDH ILOZ (input) INTEGER IHIZ (input) INTEGER Specify the rows of Z to which transformations must be applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N. Z (input/output) COMPLEX*16 array, dimension (LDZ,N) IF WANTZ is .TRUE., then on output, the unitary similarity transformation mentioned above has been accumulated into Z(ILOZ:IHIZ,ILO:IHI) from the right. If WANTZ is .FALSE., then Z is unreferenced. LDZ (input) integer The leading dimension of Z just as declared in the calling subroutine. 1 .LE. LDZ. NS (output) integer The number of unconverged (ie approximate) eigenvalues returned in SR and SI that may be used as shifts by the calling subroutine. ND (output) integer The number of converged eigenvalues uncovered by this subroutine. SH (output) COMPLEX*16 array, dimension KBOT On output, approximate eigenvalues that may be used for shifts are stored in SH(KBOT-ND-NS+1) through SR(KBOT-ND). Converged eigenvalues are stored in SH(KBOT-ND+1) through SH(KBOT). V (workspace) COMPLEX*16 array, dimension (LDV,NW) An NW-by-NW work array. LDV (input) integer scalar The leading dimension of V just as declared in the calling subroutine. NW .LE. LDV NH (input) integer scalar The number of columns of T. NH.GE.NW. T (workspace) COMPLEX*16 array, dimension (LDT,NW) LDT (input) integer The leading dimension of T just as declared in the calling subroutine. NW .LE. LDT NV (input) integer The number of rows of work array WV available for workspace. NV.GE.NW. WV (workspace) COMPLEX*16 array, dimension (LDWV,NW) LDWV (input) integer The leading dimension of W just as declared in the calling subroutine. NW .LE. LDV WORK (workspace) COMPLEX*16 array, dimension LWORK. On exit, WORK(1) is set to an estimate of the optimal value of LWORK for the given values of N, NW, KTOP and KBOT. LWORK (input) integer The dimension of the work array WORK. LWORK = 2*NW suffices, but greater efficiency may result from larger values of LWORK. If LWORK = -1, then a workspace query is assumed; ZLAQR2 only estimates the optimal workspace size for the given values of N, NW, KTOP and KBOT. The estimate is returned in WORK(1). No error message related to LWORK is issued by XERBLA. Neither H nor Z are accessed. ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ ==== Estimate optimal workspace. ==== */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --sh; v_dim1 = *ldv; v_offset = 1 + v_dim1; v -= v_offset; t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; wv_dim1 = *ldwv; wv_offset = 1 + wv_dim1; wv -= wv_offset; --work; /* Function Body */ /* Computing MIN */ i__1 = *nw, i__2 = *kbot - *ktop + 1; jw = min(i__1,i__2); if (jw <= 2) { lwkopt = 1; } else { /* ==== Workspace query call to ZGEHRD ==== */ i__1 = jw - 1; zgehrd_(&jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &work[1], & c_n1, &info); lwk1 = (integer) work[1].r; /* ==== Workspace query call to ZUNMHR ==== */ i__1 = jw - 1; zunmhr_("R", "N", &jw, &jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[1], &c_n1, &info); lwk2 = (integer) work[1].r; /* ==== Optimal workspace ==== */ lwkopt = jw + max(lwk1,lwk2); } /* ==== Quick return in case of workspace query. ==== */ if (*lwork == -1) { d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; return 0; } /* ==== Nothing to do ... ... for an empty active block ... ==== */ *ns = 0; *nd = 0; work[1].r = 1., work[1].i = 0.; if (*ktop > *kbot) { return 0; } /* ... nor for an empty deflation window. ==== */ if (*nw < 1) { return 0; } /* ==== Machine constants ==== */ safmin = SAFEMINIMUM; safmax = 1. / safmin; dlabad_(&safmin, &safmax); ulp = PRECISION; smlnum = safmin * ((doublereal) (*n) / ulp); /* ==== Setup deflation window ==== Computing MIN */ i__1 = *nw, i__2 = *kbot - *ktop + 1; jw = min(i__1,i__2); kwtop = *kbot - jw + 1; if (kwtop == *ktop) { s.r = 0., s.i = 0.; } else { i__1 = kwtop + (kwtop - 1) * h_dim1; s.r = h__[i__1].r, s.i = h__[i__1].i; } if (*kbot == kwtop) { /* ==== 1-by-1 deflation window: not much to do ==== */ i__1 = kwtop; i__2 = kwtop + kwtop * h_dim1; sh[i__1].r = h__[i__2].r, sh[i__1].i = h__[i__2].i; *ns = 1; *nd = 0; /* Computing MAX */ i__1 = kwtop + kwtop * h_dim1; d__5 = smlnum, d__6 = ulp * ((d__1 = h__[i__1].r, abs(d__1)) + (d__2 = d_imag(&h__[kwtop + kwtop * h_dim1]), abs(d__2))); if ((d__3 = s.r, abs(d__3)) + (d__4 = d_imag(&s), abs(d__4)) <= max( d__5,d__6)) { *ns = 0; *nd = 1; if (kwtop > *ktop) { i__1 = kwtop + (kwtop - 1) * h_dim1; h__[i__1].r = 0., h__[i__1].i = 0.; } } work[1].r = 1., work[1].i = 0.; return 0; } /* ==== Convert to spike-triangular form. (In case of a . rare QR failure, this routine continues to do . aggressive early deflation using that part of . the deflation window that converged using INFQR . here and there to keep track.) ==== */ zlacpy_("U", &jw, &jw, &h__[kwtop + kwtop * h_dim1], ldh, &t[t_offset], ldt); i__1 = jw - 1; i__2 = *ldh + 1; i__3 = *ldt + 1; zcopy_(&i__1, &h__[kwtop + 1 + kwtop * h_dim1], &i__2, &t[t_dim1 + 2], & i__3); zlaset_("A", &jw, &jw, &c_b56, &c_b57, &v[v_offset], ldv); zlahqr_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sh[kwtop], &c__1, &jw, &v[v_offset], ldv, &infqr); /* ==== Deflation detection loop ==== */ *ns = jw; ilst = infqr + 1; i__1 = jw; for (knt = infqr + 1; knt <= i__1; ++knt) { /* ==== Small spike tip deflation test ==== */ i__2 = *ns + *ns * t_dim1; foo = (d__1 = t[i__2].r, abs(d__1)) + (d__2 = d_imag(&t[*ns + *ns * t_dim1]), abs(d__2)); if (foo == 0.) { foo = (d__1 = s.r, abs(d__1)) + (d__2 = d_imag(&s), abs(d__2)); } i__2 = *ns * v_dim1 + 1; /* Computing MAX */ d__5 = smlnum, d__6 = ulp * foo; if (((d__1 = s.r, abs(d__1)) + (d__2 = d_imag(&s), abs(d__2))) * (( d__3 = v[i__2].r, abs(d__3)) + (d__4 = d_imag(&v[*ns * v_dim1 + 1]), abs(d__4))) <= max(d__5,d__6)) { /* ==== One more converged eigenvalue ==== */ --(*ns); } else { /* ==== One undeflatable eigenvalue. Move it up out of the . way. (ZTREXC can not fail in this case.) ==== */ ifst = *ns; ztrexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, & ilst, &info); ++ilst; } /* L10: */ } /* ==== Return to Hessenberg form ==== */ if (*ns == 0) { s.r = 0., s.i = 0.; } if (*ns < jw) { /* ==== sorting the diagonal of T improves accuracy for . graded matrices. ==== */ i__1 = *ns; for (i__ = infqr + 1; i__ <= i__1; ++i__) { ifst = i__; i__2 = *ns; for (j = i__ + 1; j <= i__2; ++j) { i__3 = j + j * t_dim1; i__4 = ifst + ifst * t_dim1; if ((d__1 = t[i__3].r, abs(d__1)) + (d__2 = d_imag(&t[j + j * t_dim1]), abs(d__2)) > (d__3 = t[i__4].r, abs(d__3)) + (d__4 = d_imag(&t[ifst + ifst * t_dim1]), abs(d__4)) ) { ifst = j; } /* L20: */ } ilst = i__; if (ifst != ilst) { ztrexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &info); } /* L30: */ } } /* ==== Restore shift/eigenvalue array from T ==== */ i__1 = jw; for (i__ = infqr + 1; i__ <= i__1; ++i__) { i__2 = kwtop + i__ - 1; i__3 = i__ + i__ * t_dim1; sh[i__2].r = t[i__3].r, sh[i__2].i = t[i__3].i; /* L40: */ } if (*ns < jw || s.r == 0. && s.i == 0.) { if (*ns > 1 && (s.r != 0. || s.i != 0.)) { /* ==== Reflect spike back into lower triangle ==== */ zcopy_(ns, &v[v_offset], ldv, &work[1], &c__1); i__1 = *ns; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__; d_cnjg(&z__1, &work[i__]); work[i__2].r = z__1.r, work[i__2].i = z__1.i; /* L50: */ } beta.r = work[1].r, beta.i = work[1].i; zlarfg_(ns, &beta, &work[2], &c__1, &tau); work[1].r = 1., work[1].i = 0.; i__1 = jw - 2; i__2 = jw - 2; zlaset_("L", &i__1, &i__2, &c_b56, &c_b56, &t[t_dim1 + 3], ldt); d_cnjg(&z__1, &tau); zlarf_("L", ns, &jw, &work[1], &c__1, &z__1, &t[t_offset], ldt, & work[jw + 1]); zlarf_("R", ns, ns, &work[1], &c__1, &tau, &t[t_offset], ldt, & work[jw + 1]); zlarf_("R", &jw, ns, &work[1], &c__1, &tau, &v[v_offset], ldv, & work[jw + 1]); i__1 = *lwork - jw; zgehrd_(&jw, &c__1, ns, &t[t_offset], ldt, &work[1], &work[jw + 1] , &i__1, &info); } /* ==== Copy updated reduced window into place ==== */ if (kwtop > 1) { i__1 = kwtop + (kwtop - 1) * h_dim1; d_cnjg(&z__2, &v[v_dim1 + 1]); z__1.r = s.r * z__2.r - s.i * z__2.i, z__1.i = s.r * z__2.i + s.i * z__2.r; h__[i__1].r = z__1.r, h__[i__1].i = z__1.i; } zlacpy_("U", &jw, &jw, &t[t_offset], ldt, &h__[kwtop + kwtop * h_dim1] , ldh); i__1 = jw - 1; i__2 = *ldt + 1; i__3 = *ldh + 1; zcopy_(&i__1, &t[t_dim1 + 2], &i__2, &h__[kwtop + 1 + kwtop * h_dim1], &i__3); /* ==== Accumulate orthogonal matrix in order update . H and Z, if requested. ==== */ if (*ns > 1 && (s.r != 0. || s.i != 0.)) { i__1 = *lwork - jw; zunmhr_("R", "N", &jw, ns, &c__1, ns, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[jw + 1], &i__1, &info); } /* ==== Update vertical slab in H ==== */ if (*wantt) { ltop = 1; } else { ltop = *ktop; } i__1 = kwtop - 1; i__2 = *nv; for (krow = ltop; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow += i__2) { /* Computing MIN */ i__3 = *nv, i__4 = kwtop - krow; kln = min(i__3,i__4); zgemm_("N", "N", &kln, &jw, &jw, &c_b57, &h__[krow + kwtop * h_dim1], ldh, &v[v_offset], ldv, &c_b56, &wv[wv_offset], ldwv); zlacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &h__[krow + kwtop * h_dim1], ldh); /* L60: */ } /* ==== Update horizontal slab in H ==== */ if (*wantt) { i__2 = *n; i__1 = *nh; for (kcol = *kbot + 1; i__1 < 0 ? kcol >= i__2 : kcol <= i__2; kcol += i__1) { /* Computing MIN */ i__3 = *nh, i__4 = *n - kcol + 1; kln = min(i__3,i__4); zgemm_("C", "N", &jw, &kln, &jw, &c_b57, &v[v_offset], ldv, & h__[kwtop + kcol * h_dim1], ldh, &c_b56, &t[t_offset], ldt); zlacpy_("A", &jw, &kln, &t[t_offset], ldt, &h__[kwtop + kcol * h_dim1], ldh); /* L70: */ } } /* ==== Update vertical slab in Z ==== */ if (*wantz) { i__1 = *ihiz; i__2 = *nv; for (krow = *iloz; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow += i__2) { /* Computing MIN */ i__3 = *nv, i__4 = *ihiz - krow + 1; kln = min(i__3,i__4); zgemm_("N", "N", &kln, &jw, &jw, &c_b57, &z__[krow + kwtop * z_dim1], ldz, &v[v_offset], ldv, &c_b56, &wv[ wv_offset], ldwv); zlacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &z__[krow + kwtop * z_dim1], ldz); /* L80: */ } } } /* ==== Return the number of deflations ... ==== */ *nd = jw - *ns; /* ==== ... and the number of shifts. (Subtracting . INFQR from the spike length takes care . of the case of a rare QR failure while . calculating eigenvalues of the deflation . window.) ==== */ *ns -= infqr; /* ==== Return optimal workspace. ==== */ d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; /* ==== End of ZLAQR2 ==== */ return 0; } /* zlaqr2_ */ /* Subroutine */ int zlaqr3_(logical *wantt, logical *wantz, integer *n, integer *ktop, integer *kbot, integer *nw, doublecomplex *h__, integer *ldh, integer *iloz, integer *ihiz, doublecomplex *z__, integer *ldz, integer *ns, integer *nd, doublecomplex *sh, doublecomplex *v, integer *ldv, integer *nh, doublecomplex *t, integer *ldt, integer *nv, doublecomplex *wv, integer *ldwv, doublecomplex *work, integer *lwork) { /* System generated locals */ integer h_dim1, h_offset, t_dim1, t_offset, v_dim1, v_offset, wv_dim1, wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4; doublereal d__1, d__2, d__3, d__4, d__5, d__6; doublecomplex z__1, z__2; /* Builtin functions */ double d_imag(doublecomplex *); void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j; static doublecomplex s; static integer jw; static doublereal foo; static integer kln; static doublecomplex tau; static integer knt; static doublereal ulp; static integer lwk1, lwk2, lwk3; static doublecomplex beta; static integer kcol, info, nmin, ifst, ilst, ltop, krow; extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); static integer infqr; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer kwtop; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), dlabad_(doublereal *, doublereal *), zlaqr4_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer * ); static doublereal safmin; extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static doublereal safmax; extern /* Subroutine */ int zgehrd_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlahqr_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static doublereal smlnum; extern /* Subroutine */ int ztrexc_(char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, integer *, integer *); static integer lwkopt; extern /* Subroutine */ int zunmhr_(char *, char *, integer *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer * ); /* -- LAPACK auxiliary routine (version 3.2.1) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. -- April 2009 -- ****************************************************************** Aggressive early deflation: This subroutine accepts as input an upper Hessenberg matrix H and performs an unitary similarity transformation designed to detect and deflate fully converged eigenvalues from a trailing principal submatrix. On output H has been over- written by a new Hessenberg matrix that is a perturbation of an unitary similarity transformation of H. It is to be hoped that the final version of H has many zero subdiagonal entries. ****************************************************************** WANTT (input) LOGICAL If .TRUE., then the Hessenberg matrix H is fully updated so that the triangular Schur factor may be computed (in cooperation with the calling subroutine). If .FALSE., then only enough of H is updated to preserve the eigenvalues. WANTZ (input) LOGICAL If .TRUE., then the unitary matrix Z is updated so so that the unitary Schur factor may be computed (in cooperation with the calling subroutine). If .FALSE., then Z is not referenced. N (input) INTEGER The order of the matrix H and (if WANTZ is .TRUE.) the order of the unitary matrix Z. KTOP (input) INTEGER It is assumed that either KTOP = 1 or H(KTOP,KTOP-1)=0. KBOT and KTOP together determine an isolated block along the diagonal of the Hessenberg matrix. KBOT (input) INTEGER It is assumed without a check that either KBOT = N or H(KBOT+1,KBOT)=0. KBOT and KTOP together determine an isolated block along the diagonal of the Hessenberg matrix. NW (input) INTEGER Deflation window size. 1 .LE. NW .LE. (KBOT-KTOP+1). H (input/output) COMPLEX*16 array, dimension (LDH,N) On input the initial N-by-N section of H stores the Hessenberg matrix undergoing aggressive early deflation. On output H has been transformed by a unitary similarity transformation, perturbed, and the returned to Hessenberg form that (it is to be hoped) has some zero subdiagonal entries. LDH (input) integer Leading dimension of H just as declared in the calling subroutine. N .LE. LDH ILOZ (input) INTEGER IHIZ (input) INTEGER Specify the rows of Z to which transformations must be applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N. Z (input/output) COMPLEX*16 array, dimension (LDZ,N) IF WANTZ is .TRUE., then on output, the unitary similarity transformation mentioned above has been accumulated into Z(ILOZ:IHIZ,ILO:IHI) from the right. If WANTZ is .FALSE., then Z is unreferenced. LDZ (input) integer The leading dimension of Z just as declared in the calling subroutine. 1 .LE. LDZ. NS (output) integer The number of unconverged (ie approximate) eigenvalues returned in SR and SI that may be used as shifts by the calling subroutine. ND (output) integer The number of converged eigenvalues uncovered by this subroutine. SH (output) COMPLEX*16 array, dimension KBOT On output, approximate eigenvalues that may be used for shifts are stored in SH(KBOT-ND-NS+1) through SR(KBOT-ND). Converged eigenvalues are stored in SH(KBOT-ND+1) through SH(KBOT). V (workspace) COMPLEX*16 array, dimension (LDV,NW) An NW-by-NW work array. LDV (input) integer scalar The leading dimension of V just as declared in the calling subroutine. NW .LE. LDV NH (input) integer scalar The number of columns of T. NH.GE.NW. T (workspace) COMPLEX*16 array, dimension (LDT,NW) LDT (input) integer The leading dimension of T just as declared in the calling subroutine. NW .LE. LDT NV (input) integer The number of rows of work array WV available for workspace. NV.GE.NW. WV (workspace) COMPLEX*16 array, dimension (LDWV,NW) LDWV (input) integer The leading dimension of W just as declared in the calling subroutine. NW .LE. LDV WORK (workspace) COMPLEX*16 array, dimension LWORK. On exit, WORK(1) is set to an estimate of the optimal value of LWORK for the given values of N, NW, KTOP and KBOT. LWORK (input) integer The dimension of the work array WORK. LWORK = 2*NW suffices, but greater efficiency may result from larger values of LWORK. If LWORK = -1, then a workspace query is assumed; ZLAQR3 only estimates the optimal workspace size for the given values of N, NW, KTOP and KBOT. The estimate is returned in WORK(1). No error message related to LWORK is issued by XERBLA. Neither H nor Z are accessed. ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ ==== Estimate optimal workspace. ==== */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --sh; v_dim1 = *ldv; v_offset = 1 + v_dim1; v -= v_offset; t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; wv_dim1 = *ldwv; wv_offset = 1 + wv_dim1; wv -= wv_offset; --work; /* Function Body */ /* Computing MIN */ i__1 = *nw, i__2 = *kbot - *ktop + 1; jw = min(i__1,i__2); if (jw <= 2) { lwkopt = 1; } else { /* ==== Workspace query call to ZGEHRD ==== */ i__1 = jw - 1; zgehrd_(&jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &work[1], & c_n1, &info); lwk1 = (integer) work[1].r; /* ==== Workspace query call to ZUNMHR ==== */ i__1 = jw - 1; zunmhr_("R", "N", &jw, &jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[1], &c_n1, &info); lwk2 = (integer) work[1].r; /* ==== Workspace query call to ZLAQR4 ==== */ zlaqr4_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sh[1], &c__1, &jw, &v[v_offset], ldv, &work[1], &c_n1, &infqr); lwk3 = (integer) work[1].r; /* ==== Optimal workspace ==== Computing MAX */ i__1 = jw + max(lwk1,lwk2); lwkopt = max(i__1,lwk3); } /* ==== Quick return in case of workspace query. ==== */ if (*lwork == -1) { d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; return 0; } /* ==== Nothing to do ... ... for an empty active block ... ==== */ *ns = 0; *nd = 0; work[1].r = 1., work[1].i = 0.; if (*ktop > *kbot) { return 0; } /* ... nor for an empty deflation window. ==== */ if (*nw < 1) { return 0; } /* ==== Machine constants ==== */ safmin = SAFEMINIMUM; safmax = 1. / safmin; dlabad_(&safmin, &safmax); ulp = PRECISION; smlnum = safmin * ((doublereal) (*n) / ulp); /* ==== Setup deflation window ==== Computing MIN */ i__1 = *nw, i__2 = *kbot - *ktop + 1; jw = min(i__1,i__2); kwtop = *kbot - jw + 1; if (kwtop == *ktop) { s.r = 0., s.i = 0.; } else { i__1 = kwtop + (kwtop - 1) * h_dim1; s.r = h__[i__1].r, s.i = h__[i__1].i; } if (*kbot == kwtop) { /* ==== 1-by-1 deflation window: not much to do ==== */ i__1 = kwtop; i__2 = kwtop + kwtop * h_dim1; sh[i__1].r = h__[i__2].r, sh[i__1].i = h__[i__2].i; *ns = 1; *nd = 0; /* Computing MAX */ i__1 = kwtop + kwtop * h_dim1; d__5 = smlnum, d__6 = ulp * ((d__1 = h__[i__1].r, abs(d__1)) + (d__2 = d_imag(&h__[kwtop + kwtop * h_dim1]), abs(d__2))); if ((d__3 = s.r, abs(d__3)) + (d__4 = d_imag(&s), abs(d__4)) <= max( d__5,d__6)) { *ns = 0; *nd = 1; if (kwtop > *ktop) { i__1 = kwtop + (kwtop - 1) * h_dim1; h__[i__1].r = 0., h__[i__1].i = 0.; } } work[1].r = 1., work[1].i = 0.; return 0; } /* ==== Convert to spike-triangular form. (In case of a . rare QR failure, this routine continues to do . aggressive early deflation using that part of . the deflation window that converged using INFQR . here and there to keep track.) ==== */ zlacpy_("U", &jw, &jw, &h__[kwtop + kwtop * h_dim1], ldh, &t[t_offset], ldt); i__1 = jw - 1; i__2 = *ldh + 1; i__3 = *ldt + 1; zcopy_(&i__1, &h__[kwtop + 1 + kwtop * h_dim1], &i__2, &t[t_dim1 + 2], & i__3); zlaset_("A", &jw, &jw, &c_b56, &c_b57, &v[v_offset], ldv); nmin = ilaenv_(&c__12, "ZLAQR3", "SV", &jw, &c__1, &jw, lwork, (ftnlen)6, (ftnlen)2); if (jw > nmin) { zlaqr4_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sh[ kwtop], &c__1, &jw, &v[v_offset], ldv, &work[1], lwork, & infqr); } else { zlahqr_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sh[ kwtop], &c__1, &jw, &v[v_offset], ldv, &infqr); } /* ==== Deflation detection loop ==== */ *ns = jw; ilst = infqr + 1; i__1 = jw; for (knt = infqr + 1; knt <= i__1; ++knt) { /* ==== Small spike tip deflation test ==== */ i__2 = *ns + *ns * t_dim1; foo = (d__1 = t[i__2].r, abs(d__1)) + (d__2 = d_imag(&t[*ns + *ns * t_dim1]), abs(d__2)); if (foo == 0.) { foo = (d__1 = s.r, abs(d__1)) + (d__2 = d_imag(&s), abs(d__2)); } i__2 = *ns * v_dim1 + 1; /* Computing MAX */ d__5 = smlnum, d__6 = ulp * foo; if (((d__1 = s.r, abs(d__1)) + (d__2 = d_imag(&s), abs(d__2))) * (( d__3 = v[i__2].r, abs(d__3)) + (d__4 = d_imag(&v[*ns * v_dim1 + 1]), abs(d__4))) <= max(d__5,d__6)) { /* ==== One more converged eigenvalue ==== */ --(*ns); } else { /* ==== One undeflatable eigenvalue. Move it up out of the . way. (ZTREXC can not fail in this case.) ==== */ ifst = *ns; ztrexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, & ilst, &info); ++ilst; } /* L10: */ } /* ==== Return to Hessenberg form ==== */ if (*ns == 0) { s.r = 0., s.i = 0.; } if (*ns < jw) { /* ==== sorting the diagonal of T improves accuracy for . graded matrices. ==== */ i__1 = *ns; for (i__ = infqr + 1; i__ <= i__1; ++i__) { ifst = i__; i__2 = *ns; for (j = i__ + 1; j <= i__2; ++j) { i__3 = j + j * t_dim1; i__4 = ifst + ifst * t_dim1; if ((d__1 = t[i__3].r, abs(d__1)) + (d__2 = d_imag(&t[j + j * t_dim1]), abs(d__2)) > (d__3 = t[i__4].r, abs(d__3)) + (d__4 = d_imag(&t[ifst + ifst * t_dim1]), abs(d__4)) ) { ifst = j; } /* L20: */ } ilst = i__; if (ifst != ilst) { ztrexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &info); } /* L30: */ } } /* ==== Restore shift/eigenvalue array from T ==== */ i__1 = jw; for (i__ = infqr + 1; i__ <= i__1; ++i__) { i__2 = kwtop + i__ - 1; i__3 = i__ + i__ * t_dim1; sh[i__2].r = t[i__3].r, sh[i__2].i = t[i__3].i; /* L40: */ } if (*ns < jw || s.r == 0. && s.i == 0.) { if (*ns > 1 && (s.r != 0. || s.i != 0.)) { /* ==== Reflect spike back into lower triangle ==== */ zcopy_(ns, &v[v_offset], ldv, &work[1], &c__1); i__1 = *ns; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__; d_cnjg(&z__1, &work[i__]); work[i__2].r = z__1.r, work[i__2].i = z__1.i; /* L50: */ } beta.r = work[1].r, beta.i = work[1].i; zlarfg_(ns, &beta, &work[2], &c__1, &tau); work[1].r = 1., work[1].i = 0.; i__1 = jw - 2; i__2 = jw - 2; zlaset_("L", &i__1, &i__2, &c_b56, &c_b56, &t[t_dim1 + 3], ldt); d_cnjg(&z__1, &tau); zlarf_("L", ns, &jw, &work[1], &c__1, &z__1, &t[t_offset], ldt, & work[jw + 1]); zlarf_("R", ns, ns, &work[1], &c__1, &tau, &t[t_offset], ldt, & work[jw + 1]); zlarf_("R", &jw, ns, &work[1], &c__1, &tau, &v[v_offset], ldv, & work[jw + 1]); i__1 = *lwork - jw; zgehrd_(&jw, &c__1, ns, &t[t_offset], ldt, &work[1], &work[jw + 1] , &i__1, &info); } /* ==== Copy updated reduced window into place ==== */ if (kwtop > 1) { i__1 = kwtop + (kwtop - 1) * h_dim1; d_cnjg(&z__2, &v[v_dim1 + 1]); z__1.r = s.r * z__2.r - s.i * z__2.i, z__1.i = s.r * z__2.i + s.i * z__2.r; h__[i__1].r = z__1.r, h__[i__1].i = z__1.i; } zlacpy_("U", &jw, &jw, &t[t_offset], ldt, &h__[kwtop + kwtop * h_dim1] , ldh); i__1 = jw - 1; i__2 = *ldt + 1; i__3 = *ldh + 1; zcopy_(&i__1, &t[t_dim1 + 2], &i__2, &h__[kwtop + 1 + kwtop * h_dim1], &i__3); /* ==== Accumulate orthogonal matrix in order update . H and Z, if requested. ==== */ if (*ns > 1 && (s.r != 0. || s.i != 0.)) { i__1 = *lwork - jw; zunmhr_("R", "N", &jw, ns, &c__1, ns, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[jw + 1], &i__1, &info); } /* ==== Update vertical slab in H ==== */ if (*wantt) { ltop = 1; } else { ltop = *ktop; } i__1 = kwtop - 1; i__2 = *nv; for (krow = ltop; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow += i__2) { /* Computing MIN */ i__3 = *nv, i__4 = kwtop - krow; kln = min(i__3,i__4); zgemm_("N", "N", &kln, &jw, &jw, &c_b57, &h__[krow + kwtop * h_dim1], ldh, &v[v_offset], ldv, &c_b56, &wv[wv_offset], ldwv); zlacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &h__[krow + kwtop * h_dim1], ldh); /* L60: */ } /* ==== Update horizontal slab in H ==== */ if (*wantt) { i__2 = *n; i__1 = *nh; for (kcol = *kbot + 1; i__1 < 0 ? kcol >= i__2 : kcol <= i__2; kcol += i__1) { /* Computing MIN */ i__3 = *nh, i__4 = *n - kcol + 1; kln = min(i__3,i__4); zgemm_("C", "N", &jw, &kln, &jw, &c_b57, &v[v_offset], ldv, & h__[kwtop + kcol * h_dim1], ldh, &c_b56, &t[t_offset], ldt); zlacpy_("A", &jw, &kln, &t[t_offset], ldt, &h__[kwtop + kcol * h_dim1], ldh); /* L70: */ } } /* ==== Update vertical slab in Z ==== */ if (*wantz) { i__1 = *ihiz; i__2 = *nv; for (krow = *iloz; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow += i__2) { /* Computing MIN */ i__3 = *nv, i__4 = *ihiz - krow + 1; kln = min(i__3,i__4); zgemm_("N", "N", &kln, &jw, &jw, &c_b57, &z__[krow + kwtop * z_dim1], ldz, &v[v_offset], ldv, &c_b56, &wv[ wv_offset], ldwv); zlacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &z__[krow + kwtop * z_dim1], ldz); /* L80: */ } } } /* ==== Return the number of deflations ... ==== */ *nd = jw - *ns; /* ==== ... and the number of shifts. (Subtracting . INFQR from the spike length takes care . of the case of a rare QR failure while . calculating eigenvalues of the deflation . window.) ==== */ *ns -= infqr; /* ==== Return optimal workspace. ==== */ d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; /* ==== End of ZLAQR3 ==== */ return 0; } /* zlaqr3_ */ /* Subroutine */ int zlaqr4_(logical *wantt, logical *wantz, integer *n, integer *ilo, integer *ihi, doublecomplex *h__, integer *ldh, doublecomplex *w, integer *iloz, integer *ihiz, doublecomplex *z__, integer *ldz, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1, d__2, d__3, d__4, d__5, d__6, d__7, d__8; doublecomplex z__1, z__2, z__3, z__4, z__5; /* Builtin functions */ double d_imag(doublecomplex *); void z_sqrt(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, k; static doublereal s; static doublecomplex aa, bb, cc, dd; static integer ld, nh, it, ks, kt, ku, kv, ls, ns, nw; static doublecomplex tr2, det; static integer inf, kdu, nho, nve, kwh, nsr, nwr, kwv, ndec, ndfl, kbot, nmin; static doublecomplex swap; static integer ktop; static doublecomplex zdum[1] /* was [1][1] */; static integer kacc22, itmax, nsmax, nwmax, kwtop; extern /* Subroutine */ int zlaqr2_(logical *, logical *, integer *, integer *, integer *, integer *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer * , doublecomplex *, integer *), zlaqr5_(logical *, logical *, integer *, integer *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *); static integer nibble; extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static char jbcmpz[2]; static doublecomplex rtdisc; static integer nwupbd; static logical sorted; extern /* Subroutine */ int zlahqr_(logical *, logical *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, integer *, doublecomplex *, integer *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer lwkopt; /* -- LAPACK auxiliary routine (version 3.2) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. November 2006 This subroutine implements one level of recursion for ZLAQR0. It is a complete implementation of the small bulge multi-shift QR algorithm. It may be called by ZLAQR0 and, for large enough deflation window size, it may be called by ZLAQR3. This subroutine is identical to ZLAQR0 except that it calls ZLAQR2 instead of ZLAQR3. Purpose ======= ZLAQR4 computes the eigenvalues of a Hessenberg matrix H and, optionally, the matrices T and Z from the Schur decomposition H = Z T Z**H, where T is an upper triangular matrix (the Schur form), and Z is the unitary matrix of Schur vectors. Optionally Z may be postmultiplied into an input unitary matrix Q so that this routine can give the Schur factorization of a matrix A which has been reduced to the Hessenberg form H by the unitary matrix Q: A = Q*H*Q**H = (QZ)*H*(QZ)**H. Arguments ========= WANTT (input) LOGICAL = .TRUE. : the full Schur form T is required; = .FALSE.: only eigenvalues are required. WANTZ (input) LOGICAL = .TRUE. : the matrix of Schur vectors Z is required; = .FALSE.: Schur vectors are not required. N (input) INTEGER The order of the matrix H. N .GE. 0. ILO (input) INTEGER IHI (input) INTEGER It is assumed that H is already upper triangular in rows and columns 1:ILO-1 and IHI+1:N and, if ILO.GT.1, H(ILO,ILO-1) is zero. ILO and IHI are normally set by a previous call to ZGEBAL, and then passed to ZGEHRD when the matrix output by ZGEBAL is reduced to Hessenberg form. Otherwise, ILO and IHI should be set to 1 and N, respectively. If N.GT.0, then 1.LE.ILO.LE.IHI.LE.N. If N = 0, then ILO = 1 and IHI = 0. H (input/output) COMPLEX*16 array, dimension (LDH,N) On entry, the upper Hessenberg matrix H. On exit, if INFO = 0 and WANTT is .TRUE., then H contains the upper triangular matrix T from the Schur decomposition (the Schur form). If INFO = 0 and WANT is .FALSE., then the contents of H are unspecified on exit. (The output value of H when INFO.GT.0 is given under the description of INFO below.) This subroutine may explicitly set H(i,j) = 0 for i.GT.j and j = 1, 2, ... ILO-1 or j = IHI+1, IHI+2, ... N. LDH (input) INTEGER The leading dimension of the array H. LDH .GE. max(1,N). W (output) COMPLEX*16 array, dimension (N) The computed eigenvalues of H(ILO:IHI,ILO:IHI) are stored in W(ILO:IHI). If WANTT is .TRUE., then the eigenvalues are stored in the same order as on the diagonal of the Schur form returned in H, with W(i) = H(i,i). Z (input/output) COMPLEX*16 array, dimension (LDZ,IHI) If WANTZ is .FALSE., then Z is not referenced. If WANTZ is .TRUE., then Z(ILO:IHI,ILOZ:IHIZ) is replaced by Z(ILO:IHI,ILOZ:IHIZ)*U where U is the orthogonal Schur factor of H(ILO:IHI,ILO:IHI). (The output value of Z when INFO.GT.0 is given under the description of INFO below.) LDZ (input) INTEGER The leading dimension of the array Z. if WANTZ is .TRUE. then LDZ.GE.MAX(1,IHIZ). Otherwize, LDZ.GE.1. WORK (workspace/output) COMPLEX*16 array, dimension LWORK On exit, if LWORK = -1, WORK(1) returns an estimate of the optimal value for LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK .GE. max(1,N) is sufficient, but LWORK typically as large as 6*N may be required for optimal performance. A workspace query to determine the optimal workspace size is recommended. If LWORK = -1, then ZLAQR4 does a workspace query. In this case, ZLAQR4 checks the input parameters and estimates the optimal workspace size for the given values of N, ILO and IHI. The estimate is returned in WORK(1). No error message related to LWORK is issued by XERBLA. Neither H nor Z are accessed. INFO (output) INTEGER = 0: successful exit .GT. 0: if INFO = i, ZLAQR4 failed to compute all of the eigenvalues. Elements 1:ilo-1 and i+1:n of WR and WI contain those eigenvalues which have been successfully computed. (Failures are rare.) If INFO .GT. 0 and WANT is .FALSE., then on exit, the remaining unconverged eigenvalues are the eigen- values of the upper Hessenberg matrix rows and columns ILO through INFO of the final, output value of H. If INFO .GT. 0 and WANTT is .TRUE., then on exit (*) (initial value of H)*U = U*(final value of H) where U is a unitary matrix. The final value of H is upper Hessenberg and triangular in rows and columns INFO+1 through IHI. If INFO .GT. 0 and WANTZ is .TRUE., then on exit (final value of Z(ILO:IHI,ILOZ:IHIZ) = (initial value of Z(ILO:IHI,ILOZ:IHIZ)*U where U is the unitary matrix in (*) (regard- less of the value of WANTT.) If INFO .GT. 0 and WANTZ is .FALSE., then Z is not accessed. ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ References: K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 Performance, SIAM Journal of Matrix Analysis, volume 23, pages 929--947, 2002. K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part II: Aggressive Early Deflation, SIAM Journal of Matrix Analysis, volume 23, pages 948--973, 2002. ================================================================ ==== Matrices of order NTINY or smaller must be processed by . ZLAHQR because of insufficient subdiagonal scratch space. . (This is a hard limit.) ==== ==== Exceptional deflation windows: try to cure rare . slow convergence by varying the size of the . deflation window after KEXNW iterations. ==== ==== Exceptional shifts: try to cure rare slow convergence . with ad-hoc exceptional shifts every KEXSH iterations. . ==== ==== The constant WILK1 is used to form the exceptional . shifts. ==== */ /* Parameter adjustments */ h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; --w; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --work; /* Function Body */ *info = 0; /* ==== Quick return for N = 0: nothing to do. ==== */ if (*n == 0) { work[1].r = 1., work[1].i = 0.; return 0; } if (*n <= 11) { /* ==== Tiny matrices must use ZLAHQR. ==== */ lwkopt = 1; if (*lwork != -1) { zlahqr_(wantt, wantz, n, ilo, ihi, &h__[h_offset], ldh, &w[1], iloz, ihiz, &z__[z_offset], ldz, info); } } else { /* ==== Use small bulge multi-shift QR with aggressive early . deflation on larger-than-tiny matrices. ==== ==== Hope for the best. ==== */ *info = 0; /* ==== Set up job flags for ILAENV. ==== */ if (*wantt) { *(unsigned char *)jbcmpz = 'S'; } else { *(unsigned char *)jbcmpz = 'E'; } if (*wantz) { *(unsigned char *)&jbcmpz[1] = 'V'; } else { *(unsigned char *)&jbcmpz[1] = 'N'; } /* ==== NWR = recommended deflation window size. At this . point, N .GT. NTINY = 11, so there is enough . subdiagonal workspace for NWR.GE.2 as required. . (In fact, there is enough subdiagonal space for . NWR.GE.3.) ==== */ nwr = ilaenv_(&c__13, "ZLAQR4", jbcmpz, n, ilo, ihi, lwork, (ftnlen)6, (ftnlen)2); nwr = max(2,nwr); /* Computing MIN */ i__1 = *ihi - *ilo + 1, i__2 = (*n - 1) / 3, i__1 = min(i__1,i__2); nwr = min(i__1,nwr); /* ==== NSR = recommended number of simultaneous shifts. . At this point N .GT. NTINY = 11, so there is at . enough subdiagonal workspace for NSR to be even . and greater than or equal to two as required. ==== */ nsr = ilaenv_(&c__15, "ZLAQR4", jbcmpz, n, ilo, ihi, lwork, (ftnlen)6, (ftnlen)2); /* Computing MIN */ i__1 = nsr, i__2 = (*n + 6) / 9, i__1 = min(i__1,i__2), i__2 = *ihi - *ilo; nsr = min(i__1,i__2); /* Computing MAX */ i__1 = 2, i__2 = nsr - nsr % 2; nsr = max(i__1,i__2); /* ==== Estimate optimal workspace ==== ==== Workspace query call to ZLAQR2 ==== */ i__1 = nwr + 1; zlaqr2_(wantt, wantz, n, ilo, ihi, &i__1, &h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &w[1], &h__[h_offset], ldh, n, &h__[h_offset], ldh, n, &h__[h_offset], ldh, &work[1], &c_n1); /* ==== Optimal workspace = MAX(ZLAQR5, ZLAQR2) ==== Computing MAX */ i__1 = nsr * 3 / 2, i__2 = (integer) work[1].r; lwkopt = max(i__1,i__2); /* ==== Quick return in case of workspace query. ==== */ if (*lwork == -1) { d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; return 0; } /* ==== ZLAHQR/ZLAQR0 crossover point ==== */ nmin = ilaenv_(&c__12, "ZLAQR4", jbcmpz, n, ilo, ihi, lwork, (ftnlen) 6, (ftnlen)2); nmin = max(11,nmin); /* ==== Nibble crossover point ==== */ nibble = ilaenv_(&c__14, "ZLAQR4", jbcmpz, n, ilo, ihi, lwork, ( ftnlen)6, (ftnlen)2); nibble = max(0,nibble); /* ==== Accumulate reflections during ttswp? Use block . 2-by-2 structure during matrix-matrix multiply? ==== */ kacc22 = ilaenv_(&c__16, "ZLAQR4", jbcmpz, n, ilo, ihi, lwork, ( ftnlen)6, (ftnlen)2); kacc22 = max(0,kacc22); kacc22 = min(2,kacc22); /* ==== NWMAX = the largest possible deflation window for . which there is sufficient workspace. ==== Computing MIN */ i__1 = (*n - 1) / 3, i__2 = *lwork / 2; nwmax = min(i__1,i__2); nw = nwmax; /* ==== NSMAX = the Largest number of simultaneous shifts . for which there is sufficient workspace. ==== Computing MIN */ i__1 = (*n + 6) / 9, i__2 = (*lwork << 1) / 3; nsmax = min(i__1,i__2); nsmax -= nsmax % 2; /* ==== NDFL: an iteration count restarted at deflation. ==== */ ndfl = 1; /* ==== ITMAX = iteration limit ==== Computing MAX */ i__1 = 10, i__2 = *ihi - *ilo + 1; itmax = max(i__1,i__2) * 30; /* ==== Last row and column in the active block ==== */ kbot = *ihi; /* ==== Main Loop ==== */ i__1 = itmax; for (it = 1; it <= i__1; ++it) { /* ==== Done when KBOT falls below ILO ==== */ if (kbot < *ilo) { goto L80; } /* ==== Locate active block ==== */ i__2 = *ilo + 1; for (k = kbot; k >= i__2; --k) { i__3 = k + (k - 1) * h_dim1; if (h__[i__3].r == 0. && h__[i__3].i == 0.) { goto L20; } /* L10: */ } k = *ilo; L20: ktop = k; /* ==== Select deflation window size: . Typical Case: . If possible and advisable, nibble the entire . active block. If not, use size MIN(NWR,NWMAX) . or MIN(NWR+1,NWMAX) depending upon which has . the smaller corresponding subdiagonal entry . (a heuristic). . . Exceptional Case: . If there have been no deflations in KEXNW or . more iterations, then vary the deflation window . size. At first, because, larger windows are, . in general, more powerful than smaller ones, . rapidly increase the window to the maximum possible. . Then, gradually reduce the window size. ==== */ nh = kbot - ktop + 1; nwupbd = min(nh,nwmax); if (ndfl < 5) { nw = min(nwupbd,nwr); } else { /* Computing MIN */ i__2 = nwupbd, i__3 = nw << 1; nw = min(i__2,i__3); } if (nw < nwmax) { if (nw >= nh - 1) { nw = nh; } else { kwtop = kbot - nw + 1; i__2 = kwtop + (kwtop - 1) * h_dim1; i__3 = kwtop - 1 + (kwtop - 2) * h_dim1; if ((d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[ kwtop + (kwtop - 1) * h_dim1]), abs(d__2)) > ( d__3 = h__[i__3].r, abs(d__3)) + (d__4 = d_imag(& h__[kwtop - 1 + (kwtop - 2) * h_dim1]), abs(d__4)) ) { ++nw; } } } if (ndfl < 5) { ndec = -1; } else if (ndec >= 0 || nw >= nwupbd) { ++ndec; if (nw - ndec < 2) { ndec = 0; } nw -= ndec; } /* ==== Aggressive early deflation: . split workspace under the subdiagonal into . - an nw-by-nw work array V in the lower . left-hand-corner, . - an NW-by-at-least-NW-but-more-is-better . (NW-by-NHO) horizontal work array along . the bottom edge, . - an at-least-NW-but-more-is-better (NHV-by-NW) . vertical work array along the left-hand-edge. . ==== */ kv = *n - nw + 1; kt = nw + 1; nho = *n - nw - 1 - kt + 1; kwv = nw + 2; nve = *n - nw - kwv + 1; /* ==== Aggressive early deflation ==== */ zlaqr2_(wantt, wantz, n, &ktop, &kbot, &nw, &h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &w[1], &h__[kv + h_dim1], ldh, &nho, &h__[kv + kt * h_dim1], ldh, &nve, & h__[kwv + h_dim1], ldh, &work[1], lwork); /* ==== Adjust KBOT accounting for new deflations. ==== */ kbot -= ld; /* ==== KS points to the shifts. ==== */ ks = kbot - ls + 1; /* ==== Skip an expensive QR sweep if there is a (partly . heuristic) reason to expect that many eigenvalues . will deflate without it. Here, the QR sweep is . skipped if many eigenvalues have just been deflated . or if the remaining active block is small. */ if (ld == 0 || ld * 100 <= nw * nibble && kbot - ktop + 1 > min( nmin,nwmax)) { /* ==== NS = nominal number of simultaneous shifts. . This may be lowered (slightly) if ZLAQR2 . did not provide that many shifts. ==== Computing MIN Computing MAX */ i__4 = 2, i__5 = kbot - ktop; i__2 = min(nsmax,nsr), i__3 = max(i__4,i__5); ns = min(i__2,i__3); ns -= ns % 2; /* ==== If there have been no deflations . in a multiple of KEXSH iterations, . then try exceptional shifts. . Otherwise use shifts provided by . ZLAQR2 above or from the eigenvalues . of a trailing principal submatrix. ==== */ if (ndfl % 6 == 0) { ks = kbot - ns + 1; i__2 = ks + 1; for (i__ = kbot; i__ >= i__2; i__ += -2) { i__3 = i__; i__4 = i__ + i__ * h_dim1; i__5 = i__ + (i__ - 1) * h_dim1; d__3 = ((d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[i__ + (i__ - 1) * h_dim1]), abs( d__2))) * .75; z__1.r = h__[i__4].r + d__3, z__1.i = h__[i__4].i; w[i__3].r = z__1.r, w[i__3].i = z__1.i; i__3 = i__ - 1; i__4 = i__; w[i__3].r = w[i__4].r, w[i__3].i = w[i__4].i; /* L30: */ } } else { /* ==== Got NS/2 or fewer shifts? Use ZLAHQR . on a trailing principal submatrix to . get more. (Since NS.LE.NSMAX.LE.(N+6)/9, . there is enough space below the subdiagonal . to fit an NS-by-NS scratch array.) ==== */ if (kbot - ks + 1 <= ns / 2) { ks = kbot - ns + 1; kt = *n - ns + 1; zlacpy_("A", &ns, &ns, &h__[ks + ks * h_dim1], ldh, & h__[kt + h_dim1], ldh); zlahqr_(&c_false, &c_false, &ns, &c__1, &ns, &h__[kt + h_dim1], ldh, &w[ks], &c__1, &c__1, zdum, & c__1, &inf); ks += inf; /* ==== In case of a rare QR failure use . eigenvalues of the trailing 2-by-2 . principal submatrix. Scale to avoid . overflows, underflows and subnormals. . (The scale factor S can not be zero, . because H(KBOT,KBOT-1) is nonzero.) ==== */ if (ks >= kbot) { i__2 = kbot - 1 + (kbot - 1) * h_dim1; i__3 = kbot + (kbot - 1) * h_dim1; i__4 = kbot - 1 + kbot * h_dim1; i__5 = kbot + kbot * h_dim1; s = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[kbot - 1 + (kbot - 1) * h_dim1]), abs(d__2)) + ((d__3 = h__[i__3] .r, abs(d__3)) + (d__4 = d_imag(&h__[kbot + (kbot - 1) * h_dim1]), abs(d__4))) + (( d__5 = h__[i__4].r, abs(d__5)) + (d__6 = d_imag(&h__[kbot - 1 + kbot * h_dim1]), abs(d__6))) + ((d__7 = h__[i__5].r, abs( d__7)) + (d__8 = d_imag(&h__[kbot + kbot * h_dim1]), abs(d__8))); i__2 = kbot - 1 + (kbot - 1) * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; aa.r = z__1.r, aa.i = z__1.i; i__2 = kbot + (kbot - 1) * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; cc.r = z__1.r, cc.i = z__1.i; i__2 = kbot - 1 + kbot * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; bb.r = z__1.r, bb.i = z__1.i; i__2 = kbot + kbot * h_dim1; z__1.r = h__[i__2].r / s, z__1.i = h__[i__2].i / s; dd.r = z__1.r, dd.i = z__1.i; z__2.r = aa.r + dd.r, z__2.i = aa.i + dd.i; z__1.r = z__2.r / 2., z__1.i = z__2.i / 2.; tr2.r = z__1.r, tr2.i = z__1.i; z__3.r = aa.r - tr2.r, z__3.i = aa.i - tr2.i; z__4.r = dd.r - tr2.r, z__4.i = dd.i - tr2.i; z__2.r = z__3.r * z__4.r - z__3.i * z__4.i, z__2.i = z__3.r * z__4.i + z__3.i * z__4.r; z__5.r = bb.r * cc.r - bb.i * cc.i, z__5.i = bb.r * cc.i + bb.i * cc.r; z__1.r = z__2.r - z__5.r, z__1.i = z__2.i - z__5.i; det.r = z__1.r, det.i = z__1.i; z__2.r = -det.r, z__2.i = -det.i; z_sqrt(&z__1, &z__2); rtdisc.r = z__1.r, rtdisc.i = z__1.i; i__2 = kbot - 1; z__2.r = tr2.r + rtdisc.r, z__2.i = tr2.i + rtdisc.i; z__1.r = s * z__2.r, z__1.i = s * z__2.i; w[i__2].r = z__1.r, w[i__2].i = z__1.i; i__2 = kbot; z__2.r = tr2.r - rtdisc.r, z__2.i = tr2.i - rtdisc.i; z__1.r = s * z__2.r, z__1.i = s * z__2.i; w[i__2].r = z__1.r, w[i__2].i = z__1.i; ks = kbot - 1; } } if (kbot - ks + 1 > ns) { /* ==== Sort the shifts (Helps a little) ==== */ sorted = FALSE_; i__2 = ks + 1; for (k = kbot; k >= i__2; --k) { if (sorted) { goto L60; } sorted = TRUE_; i__3 = k - 1; for (i__ = ks; i__ <= i__3; ++i__) { i__4 = i__; i__5 = i__ + 1; if ((d__1 = w[i__4].r, abs(d__1)) + (d__2 = d_imag(&w[i__]), abs(d__2)) < (d__3 = w[i__5].r, abs(d__3)) + (d__4 = d_imag(&w[i__ + 1]), abs(d__4))) { sorted = FALSE_; i__4 = i__; swap.r = w[i__4].r, swap.i = w[i__4].i; i__4 = i__; i__5 = i__ + 1; w[i__4].r = w[i__5].r, w[i__4].i = w[i__5] .i; i__4 = i__ + 1; w[i__4].r = swap.r, w[i__4].i = swap.i; } /* L40: */ } /* L50: */ } L60: ; } } /* ==== If there are only two shifts, then use . only one. ==== */ if (kbot - ks + 1 == 2) { i__2 = kbot; i__3 = kbot + kbot * h_dim1; z__2.r = w[i__2].r - h__[i__3].r, z__2.i = w[i__2].i - h__[i__3].i; z__1.r = z__2.r, z__1.i = z__2.i; i__4 = kbot - 1; i__5 = kbot + kbot * h_dim1; z__4.r = w[i__4].r - h__[i__5].r, z__4.i = w[i__4].i - h__[i__5].i; z__3.r = z__4.r, z__3.i = z__4.i; if ((d__1 = z__1.r, abs(d__1)) + (d__2 = d_imag(&z__1), abs(d__2)) < (d__3 = z__3.r, abs(d__3)) + (d__4 = d_imag(&z__3), abs(d__4))) { i__2 = kbot - 1; i__3 = kbot; w[i__2].r = w[i__3].r, w[i__2].i = w[i__3].i; } else { i__2 = kbot; i__3 = kbot - 1; w[i__2].r = w[i__3].r, w[i__2].i = w[i__3].i; } } /* ==== Use up to NS of the the smallest magnatiude . shifts. If there aren't NS shifts available, . then use them all, possibly dropping one to . make the number of shifts even. ==== Computing MIN */ i__2 = ns, i__3 = kbot - ks + 1; ns = min(i__2,i__3); ns -= ns % 2; ks = kbot - ns + 1; /* ==== Small-bulge multi-shift QR sweep: . split workspace under the subdiagonal into . - a KDU-by-KDU work array U in the lower . left-hand-corner, . - a KDU-by-at-least-KDU-but-more-is-better . (KDU-by-NHo) horizontal work array WH along . the bottom edge, . - and an at-least-KDU-but-more-is-better-by-KDU . (NVE-by-KDU) vertical work WV arrow along . the left-hand-edge. ==== */ kdu = ns * 3 - 3; ku = *n - kdu + 1; kwh = kdu + 1; nho = *n - kdu - 3 - (kdu + 1) + 1; kwv = kdu + 4; nve = *n - kdu - kwv + 1; /* ==== Small-bulge multi-shift QR sweep ==== */ zlaqr5_(wantt, wantz, &kacc22, n, &ktop, &kbot, &ns, &w[ks], & h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, & work[1], &c__3, &h__[ku + h_dim1], ldh, &nve, &h__[ kwv + h_dim1], ldh, &nho, &h__[ku + kwh * h_dim1], ldh); } /* ==== Note progress (or the lack of it). ==== */ if (ld > 0) { ndfl = 1; } else { ++ndfl; } /* ==== End of main loop ==== L70: */ } /* ==== Iteration limit exceeded. Set INFO to show where . the problem occurred and exit. ==== */ *info = kbot; L80: ; } /* ==== Return the optimal value of LWORK. ==== */ d__1 = (doublereal) lwkopt; z__1.r = d__1, z__1.i = 0.; work[1].r = z__1.r, work[1].i = z__1.i; /* ==== End of ZLAQR4 ==== */ return 0; } /* zlaqr4_ */ /* Subroutine */ int zlaqr5_(logical *wantt, logical *wantz, integer *kacc22, integer *n, integer *ktop, integer *kbot, integer *nshfts, doublecomplex *s, doublecomplex *h__, integer *ldh, integer *iloz, integer *ihiz, doublecomplex *z__, integer *ldz, doublecomplex *v, integer *ldv, doublecomplex *u, integer *ldu, integer *nv, doublecomplex *wv, integer *ldwv, integer *nh, doublecomplex *wh, integer *ldwh) { /* System generated locals */ integer h_dim1, h_offset, u_dim1, u_offset, v_dim1, v_offset, wh_dim1, wh_offset, wv_dim1, wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4, i__5, i__6, i__7, i__8, i__9, i__10, i__11; doublereal d__1, d__2, d__3, d__4, d__5, d__6, d__7, d__8, d__9, d__10; doublecomplex z__1, z__2, z__3, z__4, z__5, z__6, z__7, z__8; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); double d_imag(doublecomplex *); /* Local variables */ static integer j, k, m, i2, j2, i4, j4, k1; static doublereal h11, h12, h21, h22; static integer m22, ns, nu; static doublecomplex vt[3]; static doublereal scl; static integer kdu, kms; static doublereal ulp; static integer knz, kzs; static doublereal tst1, tst2; static doublecomplex beta; static logical blk22, bmp22; static integer mend, jcol, jlen, jbot, mbot, jtop, jrow, mtop; static doublecomplex alpha; static logical accum; static integer ndcol, incol, krcol, nbmps; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), ztrmm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer * , doublecomplex *, integer *), dlabad_(doublereal *, doublereal *), zlaqr1_(integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, doublecomplex *); static doublereal safmin, safmax; extern /* Subroutine */ int zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *); static doublecomplex refsum; extern /* Subroutine */ int zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); static integer mstart; static doublereal smlnum; /* -- LAPACK auxiliary routine (version 3.2) -- Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. November 2006 This auxiliary subroutine called by ZLAQR0 performs a single small-bulge multi-shift QR sweep. WANTT (input) logical scalar WANTT = .true. if the triangular Schur factor is being computed. WANTT is set to .false. otherwise. WANTZ (input) logical scalar WANTZ = .true. if the unitary Schur factor is being computed. WANTZ is set to .false. otherwise. KACC22 (input) integer with value 0, 1, or 2. Specifies the computation mode of far-from-diagonal orthogonal updates. = 0: ZLAQR5 does not accumulate reflections and does not use matrix-matrix multiply to update far-from-diagonal matrix entries. = 1: ZLAQR5 accumulates reflections and uses matrix-matrix multiply to update the far-from-diagonal matrix entries. = 2: ZLAQR5 accumulates reflections, uses matrix-matrix multiply to update the far-from-diagonal matrix entries, and takes advantage of 2-by-2 block structure during matrix multiplies. N (input) integer scalar N is the order of the Hessenberg matrix H upon which this subroutine operates. KTOP (input) integer scalar KBOT (input) integer scalar These are the first and last rows and columns of an isolated diagonal block upon which the QR sweep is to be applied. It is assumed without a check that either KTOP = 1 or H(KTOP,KTOP-1) = 0 and either KBOT = N or H(KBOT+1,KBOT) = 0. NSHFTS (input) integer scalar NSHFTS gives the number of simultaneous shifts. NSHFTS must be positive and even. S (input/output) COMPLEX*16 array of size (NSHFTS) S contains the shifts of origin that define the multi- shift QR sweep. On output S may be reordered. H (input/output) COMPLEX*16 array of size (LDH,N) On input H contains a Hessenberg matrix. On output a multi-shift QR sweep with shifts SR(J)+i*SI(J) is applied to the isolated diagonal block in rows and columns KTOP through KBOT. LDH (input) integer scalar LDH is the leading dimension of H just as declared in the calling procedure. LDH.GE.MAX(1,N). ILOZ (input) INTEGER IHIZ (input) INTEGER Specify the rows of Z to which transformations must be applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N Z (input/output) COMPLEX*16 array of size (LDZ,IHI) If WANTZ = .TRUE., then the QR Sweep unitary similarity transformation is accumulated into Z(ILOZ:IHIZ,ILO:IHI) from the right. If WANTZ = .FALSE., then Z is unreferenced. LDZ (input) integer scalar LDA is the leading dimension of Z just as declared in the calling procedure. LDZ.GE.N. V (workspace) COMPLEX*16 array of size (LDV,NSHFTS/2) LDV (input) integer scalar LDV is the leading dimension of V as declared in the calling procedure. LDV.GE.3. U (workspace) COMPLEX*16 array of size (LDU,3*NSHFTS-3) LDU (input) integer scalar LDU is the leading dimension of U just as declared in the in the calling subroutine. LDU.GE.3*NSHFTS-3. NH (input) integer scalar NH is the number of columns in array WH available for workspace. NH.GE.1. WH (workspace) COMPLEX*16 array of size (LDWH,NH) LDWH (input) integer scalar Leading dimension of WH just as declared in the calling procedure. LDWH.GE.3*NSHFTS-3. NV (input) integer scalar NV is the number of rows in WV agailable for workspace. NV.GE.1. WV (workspace) COMPLEX*16 array of size (LDWV,3*NSHFTS-3) LDWV (input) integer scalar LDWV is the leading dimension of WV as declared in the in the calling subroutine. LDWV.GE.NV. ================================================================ Based on contributions by Karen Braman and Ralph Byers, Department of Mathematics, University of Kansas, USA ================================================================ Reference: K. Braman, R. Byers and R. Mathias, The Multi-Shift QR Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 Performance, SIAM Journal of Matrix Analysis, volume 23, pages 929--947, 2002. ================================================================ ==== If there are no shifts, then there is nothing to do. ==== */ /* Parameter adjustments */ --s; h_dim1 = *ldh; h_offset = 1 + h_dim1; h__ -= h_offset; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; v_dim1 = *ldv; v_offset = 1 + v_dim1; v -= v_offset; u_dim1 = *ldu; u_offset = 1 + u_dim1; u -= u_offset; wv_dim1 = *ldwv; wv_offset = 1 + wv_dim1; wv -= wv_offset; wh_dim1 = *ldwh; wh_offset = 1 + wh_dim1; wh -= wh_offset; /* Function Body */ if (*nshfts < 2) { return 0; } /* ==== If the active block is empty or 1-by-1, then there . is nothing to do. ==== */ if (*ktop >= *kbot) { return 0; } /* ==== NSHFTS is supposed to be even, but if it is odd, . then simply reduce it by one. ==== */ ns = *nshfts - *nshfts % 2; /* ==== Machine constants for deflation ==== */ safmin = SAFEMINIMUM; safmax = 1. / safmin; dlabad_(&safmin, &safmax); ulp = PRECISION; smlnum = safmin * ((doublereal) (*n) / ulp); /* ==== Use accumulated reflections to update far-from-diagonal . entries ? ==== */ accum = *kacc22 == 1 || *kacc22 == 2; /* ==== If so, exploit the 2-by-2 block structure? ==== */ blk22 = ns > 2 && *kacc22 == 2; /* ==== clear trash ==== */ if (*ktop + 2 <= *kbot) { i__1 = *ktop + 2 + *ktop * h_dim1; h__[i__1].r = 0., h__[i__1].i = 0.; } /* ==== NBMPS = number of 2-shift bulges in the chain ==== */ nbmps = ns / 2; /* ==== KDU = width of slab ==== */ kdu = nbmps * 6 - 3; /* ==== Create and chase chains of NBMPS bulges ==== */ i__1 = *kbot - 2; i__2 = nbmps * 3 - 2; for (incol = (1 - nbmps) * 3 + *ktop - 1; i__2 < 0 ? incol >= i__1 : incol <= i__1; incol += i__2) { ndcol = incol + kdu; if (accum) { zlaset_("ALL", &kdu, &kdu, &c_b56, &c_b57, &u[u_offset], ldu); } /* ==== Near-the-diagonal bulge chase. The following loop . performs the near-the-diagonal part of a small bulge . multi-shift QR sweep. Each 6*NBMPS-2 column diagonal . chunk extends from column INCOL to column NDCOL . (including both column INCOL and column NDCOL). The . following loop chases a 3*NBMPS column long chain of . NBMPS bulges 3*NBMPS-2 columns to the right. (INCOL . may be less than KTOP and and NDCOL may be greater than . KBOT indicating phantom columns from which to chase . bulges before they are actually introduced or to which . to chase bulges beyond column KBOT.) ==== Computing MIN */ i__4 = incol + nbmps * 3 - 3, i__5 = *kbot - 2; i__3 = min(i__4,i__5); for (krcol = incol; krcol <= i__3; ++krcol) { /* ==== Bulges number MTOP to MBOT are active double implicit . shift bulges. There may or may not also be small . 2-by-2 bulge, if there is room. The inactive bulges . (if any) must wait until the active bulges have moved . down the diagonal to make room. The phantom matrix . paradigm described above helps keep track. ==== Computing MAX */ i__4 = 1, i__5 = (*ktop - 1 - krcol + 2) / 3 + 1; mtop = max(i__4,i__5); /* Computing MIN */ i__4 = nbmps, i__5 = (*kbot - krcol) / 3; mbot = min(i__4,i__5); m22 = mbot + 1; bmp22 = mbot < nbmps && krcol + (m22 - 1) * 3 == *kbot - 2; /* ==== Generate reflections to chase the chain right . one column. (The minimum value of K is KTOP-1.) ==== */ i__4 = mbot; for (m = mtop; m <= i__4; ++m) { k = krcol + (m - 1) * 3; if (k == *ktop - 1) { zlaqr1_(&c__3, &h__[*ktop + *ktop * h_dim1], ldh, &s[(m << 1) - 1], &s[m * 2], &v[m * v_dim1 + 1]); i__5 = m * v_dim1 + 1; alpha.r = v[i__5].r, alpha.i = v[i__5].i; zlarfg_(&c__3, &alpha, &v[m * v_dim1 + 2], &c__1, &v[m * v_dim1 + 1]); } else { i__5 = k + 1 + k * h_dim1; beta.r = h__[i__5].r, beta.i = h__[i__5].i; i__5 = m * v_dim1 + 2; i__6 = k + 2 + k * h_dim1; v[i__5].r = h__[i__6].r, v[i__5].i = h__[i__6].i; i__5 = m * v_dim1 + 3; i__6 = k + 3 + k * h_dim1; v[i__5].r = h__[i__6].r, v[i__5].i = h__[i__6].i; zlarfg_(&c__3, &beta, &v[m * v_dim1 + 2], &c__1, &v[m * v_dim1 + 1]); /* ==== A Bulge may collapse because of vigilant . deflation or destructive underflow. In the . underflow case, try the two-small-subdiagonals . trick to try to reinflate the bulge. ==== */ i__5 = k + 3 + k * h_dim1; i__6 = k + 3 + (k + 1) * h_dim1; i__7 = k + 3 + (k + 2) * h_dim1; if (h__[i__5].r != 0. || h__[i__5].i != 0. || (h__[i__6] .r != 0. || h__[i__6].i != 0.) || h__[i__7].r == 0. && h__[i__7].i == 0.) { /* ==== Typical case: not collapsed (yet). ==== */ i__5 = k + 1 + k * h_dim1; h__[i__5].r = beta.r, h__[i__5].i = beta.i; i__5 = k + 2 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; i__5 = k + 3 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; } else { /* ==== Atypical case: collapsed. Attempt to . reintroduce ignoring H(K+1,K) and H(K+2,K). . If the fill resulting from the new . reflector is too large, then abandon it. . Otherwise, use the new one. ==== */ zlaqr1_(&c__3, &h__[k + 1 + (k + 1) * h_dim1], ldh, & s[(m << 1) - 1], &s[m * 2], vt); alpha.r = vt[0].r, alpha.i = vt[0].i; zlarfg_(&c__3, &alpha, &vt[1], &c__1, vt); d_cnjg(&z__2, vt); i__5 = k + 1 + k * h_dim1; d_cnjg(&z__5, &vt[1]); i__6 = k + 2 + k * h_dim1; z__4.r = z__5.r * h__[i__6].r - z__5.i * h__[i__6].i, z__4.i = z__5.r * h__[i__6].i + z__5.i * h__[ i__6].r; z__3.r = h__[i__5].r + z__4.r, z__3.i = h__[i__5].i + z__4.i; z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i = z__2.r * z__3.i + z__2.i * z__3.r; refsum.r = z__1.r, refsum.i = z__1.i; i__5 = k + 2 + k * h_dim1; z__3.r = refsum.r * vt[1].r - refsum.i * vt[1].i, z__3.i = refsum.r * vt[1].i + refsum.i * vt[1] .r; z__2.r = h__[i__5].r - z__3.r, z__2.i = h__[i__5].i - z__3.i; z__1.r = z__2.r, z__1.i = z__2.i; z__5.r = refsum.r * vt[2].r - refsum.i * vt[2].i, z__5.i = refsum.r * vt[2].i + refsum.i * vt[2] .r; z__4.r = z__5.r, z__4.i = z__5.i; i__6 = k + k * h_dim1; i__7 = k + 1 + (k + 1) * h_dim1; i__8 = k + 2 + (k + 2) * h_dim1; if ((d__1 = z__1.r, abs(d__1)) + (d__2 = d_imag(&z__1) , abs(d__2)) + ((d__3 = z__4.r, abs(d__3)) + ( d__4 = d_imag(&z__4), abs(d__4))) > ulp * (( d__5 = h__[i__6].r, abs(d__5)) + (d__6 = d_imag(&h__[k + k * h_dim1]), abs(d__6)) + (( d__7 = h__[i__7].r, abs(d__7)) + (d__8 = d_imag(&h__[k + 1 + (k + 1) * h_dim1]), abs( d__8))) + ((d__9 = h__[i__8].r, abs(d__9)) + ( d__10 = d_imag(&h__[k + 2 + (k + 2) * h_dim1]) , abs(d__10))))) { /* ==== Starting a new bulge here would . create non-negligible fill. Use . the old one with trepidation. ==== */ i__5 = k + 1 + k * h_dim1; h__[i__5].r = beta.r, h__[i__5].i = beta.i; i__5 = k + 2 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; i__5 = k + 3 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; } else { /* ==== Stating a new bulge here would . create only negligible fill. . Replace the old reflector with . the new one. ==== */ i__5 = k + 1 + k * h_dim1; i__6 = k + 1 + k * h_dim1; z__1.r = h__[i__6].r - refsum.r, z__1.i = h__[ i__6].i - refsum.i; h__[i__5].r = z__1.r, h__[i__5].i = z__1.i; i__5 = k + 2 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; i__5 = k + 3 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; i__5 = m * v_dim1 + 1; v[i__5].r = vt[0].r, v[i__5].i = vt[0].i; i__5 = m * v_dim1 + 2; v[i__5].r = vt[1].r, v[i__5].i = vt[1].i; i__5 = m * v_dim1 + 3; v[i__5].r = vt[2].r, v[i__5].i = vt[2].i; } } } /* L10: */ } /* ==== Generate a 2-by-2 reflection, if needed. ==== */ k = krcol + (m22 - 1) * 3; if (bmp22) { if (k == *ktop - 1) { zlaqr1_(&c__2, &h__[k + 1 + (k + 1) * h_dim1], ldh, &s[( m22 << 1) - 1], &s[m22 * 2], &v[m22 * v_dim1 + 1]) ; i__4 = m22 * v_dim1 + 1; beta.r = v[i__4].r, beta.i = v[i__4].i; zlarfg_(&c__2, &beta, &v[m22 * v_dim1 + 2], &c__1, &v[m22 * v_dim1 + 1]); } else { i__4 = k + 1 + k * h_dim1; beta.r = h__[i__4].r, beta.i = h__[i__4].i; i__4 = m22 * v_dim1 + 2; i__5 = k + 2 + k * h_dim1; v[i__4].r = h__[i__5].r, v[i__4].i = h__[i__5].i; zlarfg_(&c__2, &beta, &v[m22 * v_dim1 + 2], &c__1, &v[m22 * v_dim1 + 1]); i__4 = k + 1 + k * h_dim1; h__[i__4].r = beta.r, h__[i__4].i = beta.i; i__4 = k + 2 + k * h_dim1; h__[i__4].r = 0., h__[i__4].i = 0.; } } /* ==== Multiply H by reflections from the left ==== */ if (accum) { jbot = min(ndcol,*kbot); } else if (*wantt) { jbot = *n; } else { jbot = *kbot; } i__4 = jbot; for (j = max(*ktop,krcol); j <= i__4; ++j) { /* Computing MIN */ i__5 = mbot, i__6 = (j - krcol + 2) / 3; mend = min(i__5,i__6); i__5 = mend; for (m = mtop; m <= i__5; ++m) { k = krcol + (m - 1) * 3; d_cnjg(&z__2, &v[m * v_dim1 + 1]); i__6 = k + 1 + j * h_dim1; d_cnjg(&z__6, &v[m * v_dim1 + 2]); i__7 = k + 2 + j * h_dim1; z__5.r = z__6.r * h__[i__7].r - z__6.i * h__[i__7].i, z__5.i = z__6.r * h__[i__7].i + z__6.i * h__[i__7] .r; z__4.r = h__[i__6].r + z__5.r, z__4.i = h__[i__6].i + z__5.i; d_cnjg(&z__8, &v[m * v_dim1 + 3]); i__8 = k + 3 + j * h_dim1; z__7.r = z__8.r * h__[i__8].r - z__8.i * h__[i__8].i, z__7.i = z__8.r * h__[i__8].i + z__8.i * h__[i__8] .r; z__3.r = z__4.r + z__7.r, z__3.i = z__4.i + z__7.i; z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i = z__2.r * z__3.i + z__2.i * z__3.r; refsum.r = z__1.r, refsum.i = z__1.i; i__6 = k + 1 + j * h_dim1; i__7 = k + 1 + j * h_dim1; z__1.r = h__[i__7].r - refsum.r, z__1.i = h__[i__7].i - refsum.i; h__[i__6].r = z__1.r, h__[i__6].i = z__1.i; i__6 = k + 2 + j * h_dim1; i__7 = k + 2 + j * h_dim1; i__8 = m * v_dim1 + 2; z__2.r = refsum.r * v[i__8].r - refsum.i * v[i__8].i, z__2.i = refsum.r * v[i__8].i + refsum.i * v[i__8] .r; z__1.r = h__[i__7].r - z__2.r, z__1.i = h__[i__7].i - z__2.i; h__[i__6].r = z__1.r, h__[i__6].i = z__1.i; i__6 = k + 3 + j * h_dim1; i__7 = k + 3 + j * h_dim1; i__8 = m * v_dim1 + 3; z__2.r = refsum.r * v[i__8].r - refsum.i * v[i__8].i, z__2.i = refsum.r * v[i__8].i + refsum.i * v[i__8] .r; z__1.r = h__[i__7].r - z__2.r, z__1.i = h__[i__7].i - z__2.i; h__[i__6].r = z__1.r, h__[i__6].i = z__1.i; /* L20: */ } /* L30: */ } if (bmp22) { k = krcol + (m22 - 1) * 3; /* Computing MAX */ i__4 = k + 1; i__5 = jbot; for (j = max(i__4,*ktop); j <= i__5; ++j) { d_cnjg(&z__2, &v[m22 * v_dim1 + 1]); i__4 = k + 1 + j * h_dim1; d_cnjg(&z__5, &v[m22 * v_dim1 + 2]); i__6 = k + 2 + j * h_dim1; z__4.r = z__5.r * h__[i__6].r - z__5.i * h__[i__6].i, z__4.i = z__5.r * h__[i__6].i + z__5.i * h__[i__6] .r; z__3.r = h__[i__4].r + z__4.r, z__3.i = h__[i__4].i + z__4.i; z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i = z__2.r * z__3.i + z__2.i * z__3.r; refsum.r = z__1.r, refsum.i = z__1.i; i__4 = k + 1 + j * h_dim1; i__6 = k + 1 + j * h_dim1; z__1.r = h__[i__6].r - refsum.r, z__1.i = h__[i__6].i - refsum.i; h__[i__4].r = z__1.r, h__[i__4].i = z__1.i; i__4 = k + 2 + j * h_dim1; i__6 = k + 2 + j * h_dim1; i__7 = m22 * v_dim1 + 2; z__2.r = refsum.r * v[i__7].r - refsum.i * v[i__7].i, z__2.i = refsum.r * v[i__7].i + refsum.i * v[i__7] .r; z__1.r = h__[i__6].r - z__2.r, z__1.i = h__[i__6].i - z__2.i; h__[i__4].r = z__1.r, h__[i__4].i = z__1.i; /* L40: */ } } /* ==== Multiply H by reflections from the right. . Delay filling in the last row until the . vigilant deflation check is complete. ==== */ if (accum) { jtop = max(*ktop,incol); } else if (*wantt) { jtop = 1; } else { jtop = *ktop; } i__5 = mbot; for (m = mtop; m <= i__5; ++m) { i__4 = m * v_dim1 + 1; if (v[i__4].r != 0. || v[i__4].i != 0.) { k = krcol + (m - 1) * 3; /* Computing MIN */ i__6 = *kbot, i__7 = k + 3; i__4 = min(i__6,i__7); for (j = jtop; j <= i__4; ++j) { i__6 = m * v_dim1 + 1; i__7 = j + (k + 1) * h_dim1; i__8 = m * v_dim1 + 2; i__9 = j + (k + 2) * h_dim1; z__4.r = v[i__8].r * h__[i__9].r - v[i__8].i * h__[ i__9].i, z__4.i = v[i__8].r * h__[i__9].i + v[ i__8].i * h__[i__9].r; z__3.r = h__[i__7].r + z__4.r, z__3.i = h__[i__7].i + z__4.i; i__10 = m * v_dim1 + 3; i__11 = j + (k + 3) * h_dim1; z__5.r = v[i__10].r * h__[i__11].r - v[i__10].i * h__[ i__11].i, z__5.i = v[i__10].r * h__[i__11].i + v[i__10].i * h__[i__11].r; z__2.r = z__3.r + z__5.r, z__2.i = z__3.i + z__5.i; z__1.r = v[i__6].r * z__2.r - v[i__6].i * z__2.i, z__1.i = v[i__6].r * z__2.i + v[i__6].i * z__2.r; refsum.r = z__1.r, refsum.i = z__1.i; i__6 = j + (k + 1) * h_dim1; i__7 = j + (k + 1) * h_dim1; z__1.r = h__[i__7].r - refsum.r, z__1.i = h__[i__7].i - refsum.i; h__[i__6].r = z__1.r, h__[i__6].i = z__1.i; i__6 = j + (k + 2) * h_dim1; i__7 = j + (k + 2) * h_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 2]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = h__[i__7].r - z__2.r, z__1.i = h__[i__7].i - z__2.i; h__[i__6].r = z__1.r, h__[i__6].i = z__1.i; i__6 = j + (k + 3) * h_dim1; i__7 = j + (k + 3) * h_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 3]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = h__[i__7].r - z__2.r, z__1.i = h__[i__7].i - z__2.i; h__[i__6].r = z__1.r, h__[i__6].i = z__1.i; /* L50: */ } if (accum) { /* ==== Accumulate U. (If necessary, update Z later . with with an efficient matrix-matrix . multiply.) ==== */ kms = k - incol; /* Computing MAX */ i__4 = 1, i__6 = *ktop - incol; i__7 = kdu; for (j = max(i__4,i__6); j <= i__7; ++j) { i__4 = m * v_dim1 + 1; i__6 = j + (kms + 1) * u_dim1; i__8 = m * v_dim1 + 2; i__9 = j + (kms + 2) * u_dim1; z__4.r = v[i__8].r * u[i__9].r - v[i__8].i * u[ i__9].i, z__4.i = v[i__8].r * u[i__9].i + v[i__8].i * u[i__9].r; z__3.r = u[i__6].r + z__4.r, z__3.i = u[i__6].i + z__4.i; i__10 = m * v_dim1 + 3; i__11 = j + (kms + 3) * u_dim1; z__5.r = v[i__10].r * u[i__11].r - v[i__10].i * u[ i__11].i, z__5.i = v[i__10].r * u[i__11] .i + v[i__10].i * u[i__11].r; z__2.r = z__3.r + z__5.r, z__2.i = z__3.i + z__5.i; z__1.r = v[i__4].r * z__2.r - v[i__4].i * z__2.i, z__1.i = v[i__4].r * z__2.i + v[i__4].i * z__2.r; refsum.r = z__1.r, refsum.i = z__1.i; i__4 = j + (kms + 1) * u_dim1; i__6 = j + (kms + 1) * u_dim1; z__1.r = u[i__6].r - refsum.r, z__1.i = u[i__6].i - refsum.i; u[i__4].r = z__1.r, u[i__4].i = z__1.i; i__4 = j + (kms + 2) * u_dim1; i__6 = j + (kms + 2) * u_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 2]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = u[i__6].r - z__2.r, z__1.i = u[i__6].i - z__2.i; u[i__4].r = z__1.r, u[i__4].i = z__1.i; i__4 = j + (kms + 3) * u_dim1; i__6 = j + (kms + 3) * u_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 3]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = u[i__6].r - z__2.r, z__1.i = u[i__6].i - z__2.i; u[i__4].r = z__1.r, u[i__4].i = z__1.i; /* L60: */ } } else if (*wantz) { /* ==== U is not accumulated, so update Z . now by multiplying by reflections . from the right. ==== */ i__7 = *ihiz; for (j = *iloz; j <= i__7; ++j) { i__4 = m * v_dim1 + 1; i__6 = j + (k + 1) * z_dim1; i__8 = m * v_dim1 + 2; i__9 = j + (k + 2) * z_dim1; z__4.r = v[i__8].r * z__[i__9].r - v[i__8].i * z__[i__9].i, z__4.i = v[i__8].r * z__[ i__9].i + v[i__8].i * z__[i__9].r; z__3.r = z__[i__6].r + z__4.r, z__3.i = z__[i__6] .i + z__4.i; i__10 = m * v_dim1 + 3; i__11 = j + (k + 3) * z_dim1; z__5.r = v[i__10].r * z__[i__11].r - v[i__10].i * z__[i__11].i, z__5.i = v[i__10].r * z__[ i__11].i + v[i__10].i * z__[i__11].r; z__2.r = z__3.r + z__5.r, z__2.i = z__3.i + z__5.i; z__1.r = v[i__4].r * z__2.r - v[i__4].i * z__2.i, z__1.i = v[i__4].r * z__2.i + v[i__4].i * z__2.r; refsum.r = z__1.r, refsum.i = z__1.i; i__4 = j + (k + 1) * z_dim1; i__6 = j + (k + 1) * z_dim1; z__1.r = z__[i__6].r - refsum.r, z__1.i = z__[ i__6].i - refsum.i; z__[i__4].r = z__1.r, z__[i__4].i = z__1.i; i__4 = j + (k + 2) * z_dim1; i__6 = j + (k + 2) * z_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 2]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = z__[i__6].r - z__2.r, z__1.i = z__[i__6] .i - z__2.i; z__[i__4].r = z__1.r, z__[i__4].i = z__1.i; i__4 = j + (k + 3) * z_dim1; i__6 = j + (k + 3) * z_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 3]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = z__[i__6].r - z__2.r, z__1.i = z__[i__6] .i - z__2.i; z__[i__4].r = z__1.r, z__[i__4].i = z__1.i; /* L70: */ } } } /* L80: */ } /* ==== Special case: 2-by-2 reflection (if needed) ==== */ k = krcol + (m22 - 1) * 3; i__5 = m22 * v_dim1 + 1; if (bmp22 && (v[i__5].r != 0. || v[i__5].i != 0.)) { /* Computing MIN */ i__7 = *kbot, i__4 = k + 3; i__5 = min(i__7,i__4); for (j = jtop; j <= i__5; ++j) { i__7 = m22 * v_dim1 + 1; i__4 = j + (k + 1) * h_dim1; i__6 = m22 * v_dim1 + 2; i__8 = j + (k + 2) * h_dim1; z__3.r = v[i__6].r * h__[i__8].r - v[i__6].i * h__[i__8] .i, z__3.i = v[i__6].r * h__[i__8].i + v[i__6].i * h__[i__8].r; z__2.r = h__[i__4].r + z__3.r, z__2.i = h__[i__4].i + z__3.i; z__1.r = v[i__7].r * z__2.r - v[i__7].i * z__2.i, z__1.i = v[i__7].r * z__2.i + v[i__7].i * z__2.r; refsum.r = z__1.r, refsum.i = z__1.i; i__7 = j + (k + 1) * h_dim1; i__4 = j + (k + 1) * h_dim1; z__1.r = h__[i__4].r - refsum.r, z__1.i = h__[i__4].i - refsum.i; h__[i__7].r = z__1.r, h__[i__7].i = z__1.i; i__7 = j + (k + 2) * h_dim1; i__4 = j + (k + 2) * h_dim1; d_cnjg(&z__3, &v[m22 * v_dim1 + 2]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = h__[i__4].r - z__2.r, z__1.i = h__[i__4].i - z__2.i; h__[i__7].r = z__1.r, h__[i__7].i = z__1.i; /* L90: */ } if (accum) { kms = k - incol; /* Computing MAX */ i__5 = 1, i__7 = *ktop - incol; i__4 = kdu; for (j = max(i__5,i__7); j <= i__4; ++j) { i__5 = m22 * v_dim1 + 1; i__7 = j + (kms + 1) * u_dim1; i__6 = m22 * v_dim1 + 2; i__8 = j + (kms + 2) * u_dim1; z__3.r = v[i__6].r * u[i__8].r - v[i__6].i * u[i__8] .i, z__3.i = v[i__6].r * u[i__8].i + v[i__6] .i * u[i__8].r; z__2.r = u[i__7].r + z__3.r, z__2.i = u[i__7].i + z__3.i; z__1.r = v[i__5].r * z__2.r - v[i__5].i * z__2.i, z__1.i = v[i__5].r * z__2.i + v[i__5].i * z__2.r; refsum.r = z__1.r, refsum.i = z__1.i; i__5 = j + (kms + 1) * u_dim1; i__7 = j + (kms + 1) * u_dim1; z__1.r = u[i__7].r - refsum.r, z__1.i = u[i__7].i - refsum.i; u[i__5].r = z__1.r, u[i__5].i = z__1.i; i__5 = j + (kms + 2) * u_dim1; i__7 = j + (kms + 2) * u_dim1; d_cnjg(&z__3, &v[m22 * v_dim1 + 2]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = u[i__7].r - z__2.r, z__1.i = u[i__7].i - z__2.i; u[i__5].r = z__1.r, u[i__5].i = z__1.i; /* L100: */ } } else if (*wantz) { i__4 = *ihiz; for (j = *iloz; j <= i__4; ++j) { i__5 = m22 * v_dim1 + 1; i__7 = j + (k + 1) * z_dim1; i__6 = m22 * v_dim1 + 2; i__8 = j + (k + 2) * z_dim1; z__3.r = v[i__6].r * z__[i__8].r - v[i__6].i * z__[ i__8].i, z__3.i = v[i__6].r * z__[i__8].i + v[ i__6].i * z__[i__8].r; z__2.r = z__[i__7].r + z__3.r, z__2.i = z__[i__7].i + z__3.i; z__1.r = v[i__5].r * z__2.r - v[i__5].i * z__2.i, z__1.i = v[i__5].r * z__2.i + v[i__5].i * z__2.r; refsum.r = z__1.r, refsum.i = z__1.i; i__5 = j + (k + 1) * z_dim1; i__7 = j + (k + 1) * z_dim1; z__1.r = z__[i__7].r - refsum.r, z__1.i = z__[i__7].i - refsum.i; z__[i__5].r = z__1.r, z__[i__5].i = z__1.i; i__5 = j + (k + 2) * z_dim1; i__7 = j + (k + 2) * z_dim1; d_cnjg(&z__3, &v[m22 * v_dim1 + 2]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = z__[i__7].r - z__2.r, z__1.i = z__[i__7].i - z__2.i; z__[i__5].r = z__1.r, z__[i__5].i = z__1.i; /* L110: */ } } } /* ==== Vigilant deflation check ==== */ mstart = mtop; if (krcol + (mstart - 1) * 3 < *ktop) { ++mstart; } mend = mbot; if (bmp22) { ++mend; } if (krcol == *kbot - 2) { ++mend; } i__4 = mend; for (m = mstart; m <= i__4; ++m) { /* Computing MIN */ i__5 = *kbot - 1, i__7 = krcol + (m - 1) * 3; k = min(i__5,i__7); /* ==== The following convergence test requires that . the tradition small-compared-to-nearby-diagonals . criterion and the Ahues & Tisseur (LAWN 122, 1997) . criteria both be satisfied. The latter improves . accuracy in some examples. Falling back on an . alternate convergence criterion when TST1 or TST2 . is zero (as done here) is traditional but probably . unnecessary. ==== */ i__5 = k + 1 + k * h_dim1; if (h__[i__5].r != 0. || h__[i__5].i != 0.) { i__5 = k + k * h_dim1; i__7 = k + 1 + (k + 1) * h_dim1; tst1 = (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(& h__[k + k * h_dim1]), abs(d__2)) + ((d__3 = h__[ i__7].r, abs(d__3)) + (d__4 = d_imag(&h__[k + 1 + (k + 1) * h_dim1]), abs(d__4))); if (tst1 == 0.) { if (k >= *ktop + 1) { i__5 = k + (k - 1) * h_dim1; tst1 += (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + (k - 1) * h_dim1]), abs( d__2)); } if (k >= *ktop + 2) { i__5 = k + (k - 2) * h_dim1; tst1 += (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + (k - 2) * h_dim1]), abs( d__2)); } if (k >= *ktop + 3) { i__5 = k + (k - 3) * h_dim1; tst1 += (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + (k - 3) * h_dim1]), abs( d__2)); } if (k <= *kbot - 2) { i__5 = k + 2 + (k + 1) * h_dim1; tst1 += (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 2 + (k + 1) * h_dim1]), abs(d__2)); } if (k <= *kbot - 3) { i__5 = k + 3 + (k + 1) * h_dim1; tst1 += (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 3 + (k + 1) * h_dim1]), abs(d__2)); } if (k <= *kbot - 4) { i__5 = k + 4 + (k + 1) * h_dim1; tst1 += (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 4 + (k + 1) * h_dim1]), abs(d__2)); } } i__5 = k + 1 + k * h_dim1; /* Computing MAX */ d__3 = smlnum, d__4 = ulp * tst1; if ((d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[ k + 1 + k * h_dim1]), abs(d__2)) <= max(d__3,d__4) ) { /* Computing MAX */ i__5 = k + 1 + k * h_dim1; i__7 = k + (k + 1) * h_dim1; d__5 = (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 1 + k * h_dim1]), abs(d__2)), d__6 = (d__3 = h__[i__7].r, abs(d__3)) + ( d__4 = d_imag(&h__[k + (k + 1) * h_dim1]), abs(d__4)); h12 = max(d__5,d__6); /* Computing MIN */ i__5 = k + 1 + k * h_dim1; i__7 = k + (k + 1) * h_dim1; d__5 = (d__1 = h__[i__5].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 1 + k * h_dim1]), abs(d__2)), d__6 = (d__3 = h__[i__7].r, abs(d__3)) + ( d__4 = d_imag(&h__[k + (k + 1) * h_dim1]), abs(d__4)); h21 = min(d__5,d__6); i__5 = k + k * h_dim1; i__7 = k + 1 + (k + 1) * h_dim1; z__2.r = h__[i__5].r - h__[i__7].r, z__2.i = h__[i__5] .i - h__[i__7].i; z__1.r = z__2.r, z__1.i = z__2.i; /* Computing MAX */ i__6 = k + 1 + (k + 1) * h_dim1; d__5 = (d__1 = h__[i__6].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 1 + (k + 1) * h_dim1]), abs( d__2)), d__6 = (d__3 = z__1.r, abs(d__3)) + ( d__4 = d_imag(&z__1), abs(d__4)); h11 = max(d__5,d__6); i__5 = k + k * h_dim1; i__7 = k + 1 + (k + 1) * h_dim1; z__2.r = h__[i__5].r - h__[i__7].r, z__2.i = h__[i__5] .i - h__[i__7].i; z__1.r = z__2.r, z__1.i = z__2.i; /* Computing MIN */ i__6 = k + 1 + (k + 1) * h_dim1; d__5 = (d__1 = h__[i__6].r, abs(d__1)) + (d__2 = d_imag(&h__[k + 1 + (k + 1) * h_dim1]), abs( d__2)), d__6 = (d__3 = z__1.r, abs(d__3)) + ( d__4 = d_imag(&z__1), abs(d__4)); h22 = min(d__5,d__6); scl = h11 + h12; tst2 = h22 * (h11 / scl); /* Computing MAX */ d__1 = smlnum, d__2 = ulp * tst2; if (tst2 == 0. || h21 * (h12 / scl) <= max(d__1,d__2)) { i__5 = k + 1 + k * h_dim1; h__[i__5].r = 0., h__[i__5].i = 0.; } } } /* L120: */ } /* ==== Fill in the last row of each bulge. ==== Computing MIN */ i__4 = nbmps, i__5 = (*kbot - krcol - 1) / 3; mend = min(i__4,i__5); i__4 = mend; for (m = mtop; m <= i__4; ++m) { k = krcol + (m - 1) * 3; i__5 = m * v_dim1 + 1; i__7 = m * v_dim1 + 3; z__2.r = v[i__5].r * v[i__7].r - v[i__5].i * v[i__7].i, z__2.i = v[i__5].r * v[i__7].i + v[i__5].i * v[i__7] .r; i__6 = k + 4 + (k + 3) * h_dim1; z__1.r = z__2.r * h__[i__6].r - z__2.i * h__[i__6].i, z__1.i = z__2.r * h__[i__6].i + z__2.i * h__[i__6].r; refsum.r = z__1.r, refsum.i = z__1.i; i__5 = k + 4 + (k + 1) * h_dim1; z__1.r = -refsum.r, z__1.i = -refsum.i; h__[i__5].r = z__1.r, h__[i__5].i = z__1.i; i__5 = k + 4 + (k + 2) * h_dim1; z__2.r = -refsum.r, z__2.i = -refsum.i; d_cnjg(&z__3, &v[m * v_dim1 + 2]); z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i = z__2.r * z__3.i + z__2.i * z__3.r; h__[i__5].r = z__1.r, h__[i__5].i = z__1.i; i__5 = k + 4 + (k + 3) * h_dim1; i__7 = k + 4 + (k + 3) * h_dim1; d_cnjg(&z__3, &v[m * v_dim1 + 3]); z__2.r = refsum.r * z__3.r - refsum.i * z__3.i, z__2.i = refsum.r * z__3.i + refsum.i * z__3.r; z__1.r = h__[i__7].r - z__2.r, z__1.i = h__[i__7].i - z__2.i; h__[i__5].r = z__1.r, h__[i__5].i = z__1.i; /* L130: */ } /* ==== End of near-the-diagonal bulge chase. ==== L140: */ } /* ==== Use U (if accumulated) to update far-from-diagonal . entries in H. If required, use U to update Z as . well. ==== */ if (accum) { if (*wantt) { jtop = 1; jbot = *n; } else { jtop = *ktop; jbot = *kbot; } if (! blk22 || incol < *ktop || ndcol > *kbot || ns <= 2) { /* ==== Updates not exploiting the 2-by-2 block . structure of U. K1 and NU keep track of . the location and size of U in the special . cases of introducing bulges and chasing . bulges off the bottom. In these special . cases and in case the number of shifts . is NS = 2, there is no 2-by-2 block . structure to exploit. ==== Computing MAX */ i__3 = 1, i__4 = *ktop - incol; k1 = max(i__3,i__4); /* Computing MAX */ i__3 = 0, i__4 = ndcol - *kbot; nu = kdu - max(i__3,i__4) - k1 + 1; /* ==== Horizontal Multiply ==== */ i__3 = jbot; i__4 = *nh; for (jcol = min(ndcol,*kbot) + 1; i__4 < 0 ? jcol >= i__3 : jcol <= i__3; jcol += i__4) { /* Computing MIN */ i__5 = *nh, i__7 = jbot - jcol + 1; jlen = min(i__5,i__7); zgemm_("C", "N", &nu, &jlen, &nu, &c_b57, &u[k1 + k1 * u_dim1], ldu, &h__[incol + k1 + jcol * h_dim1], ldh, &c_b56, &wh[wh_offset], ldwh); zlacpy_("ALL", &nu, &jlen, &wh[wh_offset], ldwh, &h__[ incol + k1 + jcol * h_dim1], ldh); /* L150: */ } /* ==== Vertical multiply ==== */ i__4 = max(*ktop,incol) - 1; i__3 = *nv; for (jrow = jtop; i__3 < 0 ? jrow >= i__4 : jrow <= i__4; jrow += i__3) { /* Computing MIN */ i__5 = *nv, i__7 = max(*ktop,incol) - jrow; jlen = min(i__5,i__7); zgemm_("N", "N", &jlen, &nu, &nu, &c_b57, &h__[jrow + ( incol + k1) * h_dim1], ldh, &u[k1 + k1 * u_dim1], ldu, &c_b56, &wv[wv_offset], ldwv); zlacpy_("ALL", &jlen, &nu, &wv[wv_offset], ldwv, &h__[ jrow + (incol + k1) * h_dim1], ldh); /* L160: */ } /* ==== Z multiply (also vertical) ==== */ if (*wantz) { i__3 = *ihiz; i__4 = *nv; for (jrow = *iloz; i__4 < 0 ? jrow >= i__3 : jrow <= i__3; jrow += i__4) { /* Computing MIN */ i__5 = *nv, i__7 = *ihiz - jrow + 1; jlen = min(i__5,i__7); zgemm_("N", "N", &jlen, &nu, &nu, &c_b57, &z__[jrow + (incol + k1) * z_dim1], ldz, &u[k1 + k1 * u_dim1], ldu, &c_b56, &wv[wv_offset], ldwv); zlacpy_("ALL", &jlen, &nu, &wv[wv_offset], ldwv, &z__[ jrow + (incol + k1) * z_dim1], ldz) ; /* L170: */ } } } else { /* ==== Updates exploiting U's 2-by-2 block structure. . (I2, I4, J2, J4 are the last rows and columns . of the blocks.) ==== */ i2 = (kdu + 1) / 2; i4 = kdu; j2 = i4 - i2; j4 = kdu; /* ==== KZS and KNZ deal with the band of zeros . along the diagonal of one of the triangular . blocks. ==== */ kzs = j4 - j2 - (ns + 1); knz = ns + 1; /* ==== Horizontal multiply ==== */ i__4 = jbot; i__3 = *nh; for (jcol = min(ndcol,*kbot) + 1; i__3 < 0 ? jcol >= i__4 : jcol <= i__4; jcol += i__3) { /* Computing MIN */ i__5 = *nh, i__7 = jbot - jcol + 1; jlen = min(i__5,i__7); /* ==== Copy bottom of H to top+KZS of scratch ==== (The first KZS rows get multiplied by zero.) ==== */ zlacpy_("ALL", &knz, &jlen, &h__[incol + 1 + j2 + jcol * h_dim1], ldh, &wh[kzs + 1 + wh_dim1], ldwh); /* ==== Multiply by U21' ==== */ zlaset_("ALL", &kzs, &jlen, &c_b56, &c_b56, &wh[wh_offset] , ldwh); ztrmm_("L", "U", "C", "N", &knz, &jlen, &c_b57, &u[j2 + 1 + (kzs + 1) * u_dim1], ldu, &wh[kzs + 1 + wh_dim1] , ldwh); /* ==== Multiply top of H by U11' ==== */ zgemm_("C", "N", &i2, &jlen, &j2, &c_b57, &u[u_offset], ldu, &h__[incol + 1 + jcol * h_dim1], ldh, &c_b57, &wh[wh_offset], ldwh); /* ==== Copy top of H to bottom of WH ==== */ zlacpy_("ALL", &j2, &jlen, &h__[incol + 1 + jcol * h_dim1] , ldh, &wh[i2 + 1 + wh_dim1], ldwh); /* ==== Multiply by U21' ==== */ ztrmm_("L", "L", "C", "N", &j2, &jlen, &c_b57, &u[(i2 + 1) * u_dim1 + 1], ldu, &wh[i2 + 1 + wh_dim1], ldwh); /* ==== Multiply by U22 ==== */ i__5 = i4 - i2; i__7 = j4 - j2; zgemm_("C", "N", &i__5, &jlen, &i__7, &c_b57, &u[j2 + 1 + (i2 + 1) * u_dim1], ldu, &h__[incol + 1 + j2 + jcol * h_dim1], ldh, &c_b57, &wh[i2 + 1 + wh_dim1] , ldwh); /* ==== Copy it back ==== */ zlacpy_("ALL", &kdu, &jlen, &wh[wh_offset], ldwh, &h__[ incol + 1 + jcol * h_dim1], ldh); /* L180: */ } /* ==== Vertical multiply ==== */ i__3 = max(incol,*ktop) - 1; i__4 = *nv; for (jrow = jtop; i__4 < 0 ? jrow >= i__3 : jrow <= i__3; jrow += i__4) { /* Computing MIN */ i__5 = *nv, i__7 = max(incol,*ktop) - jrow; jlen = min(i__5,i__7); /* ==== Copy right of H to scratch (the first KZS . columns get multiplied by zero) ==== */ zlacpy_("ALL", &jlen, &knz, &h__[jrow + (incol + 1 + j2) * h_dim1], ldh, &wv[(kzs + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U21 ==== */ zlaset_("ALL", &jlen, &kzs, &c_b56, &c_b56, &wv[wv_offset] , ldwv); ztrmm_("R", "U", "N", "N", &jlen, &knz, &c_b57, &u[j2 + 1 + (kzs + 1) * u_dim1], ldu, &wv[(kzs + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U11 ==== */ zgemm_("N", "N", &jlen, &i2, &j2, &c_b57, &h__[jrow + ( incol + 1) * h_dim1], ldh, &u[u_offset], ldu, & c_b57, &wv[wv_offset], ldwv) ; /* ==== Copy left of H to right of scratch ==== */ zlacpy_("ALL", &jlen, &j2, &h__[jrow + (incol + 1) * h_dim1], ldh, &wv[(i2 + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U21 ==== */ i__5 = i4 - i2; ztrmm_("R", "L", "N", "N", &jlen, &i__5, &c_b57, &u[(i2 + 1) * u_dim1 + 1], ldu, &wv[(i2 + 1) * wv_dim1 + 1] , ldwv); /* ==== Multiply by U22 ==== */ i__5 = i4 - i2; i__7 = j4 - j2; zgemm_("N", "N", &jlen, &i__5, &i__7, &c_b57, &h__[jrow + (incol + 1 + j2) * h_dim1], ldh, &u[j2 + 1 + (i2 + 1) * u_dim1], ldu, &c_b57, &wv[(i2 + 1) * wv_dim1 + 1], ldwv); /* ==== Copy it back ==== */ zlacpy_("ALL", &jlen, &kdu, &wv[wv_offset], ldwv, &h__[ jrow + (incol + 1) * h_dim1], ldh); /* L190: */ } /* ==== Multiply Z (also vertical) ==== */ if (*wantz) { i__4 = *ihiz; i__3 = *nv; for (jrow = *iloz; i__3 < 0 ? jrow >= i__4 : jrow <= i__4; jrow += i__3) { /* Computing MIN */ i__5 = *nv, i__7 = *ihiz - jrow + 1; jlen = min(i__5,i__7); /* ==== Copy right of Z to left of scratch (first . KZS columns get multiplied by zero) ==== */ zlacpy_("ALL", &jlen, &knz, &z__[jrow + (incol + 1 + j2) * z_dim1], ldz, &wv[(kzs + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U12 ==== */ zlaset_("ALL", &jlen, &kzs, &c_b56, &c_b56, &wv[ wv_offset], ldwv); ztrmm_("R", "U", "N", "N", &jlen, &knz, &c_b57, &u[j2 + 1 + (kzs + 1) * u_dim1], ldu, &wv[(kzs + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U11 ==== */ zgemm_("N", "N", &jlen, &i2, &j2, &c_b57, &z__[jrow + (incol + 1) * z_dim1], ldz, &u[u_offset], ldu, &c_b57, &wv[wv_offset], ldwv); /* ==== Copy left of Z to right of scratch ==== */ zlacpy_("ALL", &jlen, &j2, &z__[jrow + (incol + 1) * z_dim1], ldz, &wv[(i2 + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U21 ==== */ i__5 = i4 - i2; ztrmm_("R", "L", "N", "N", &jlen, &i__5, &c_b57, &u[( i2 + 1) * u_dim1 + 1], ldu, &wv[(i2 + 1) * wv_dim1 + 1], ldwv); /* ==== Multiply by U22 ==== */ i__5 = i4 - i2; i__7 = j4 - j2; zgemm_("N", "N", &jlen, &i__5, &i__7, &c_b57, &z__[ jrow + (incol + 1 + j2) * z_dim1], ldz, &u[j2 + 1 + (i2 + 1) * u_dim1], ldu, &c_b57, &wv[( i2 + 1) * wv_dim1 + 1], ldwv); /* ==== Copy the result back to Z ==== */ zlacpy_("ALL", &jlen, &kdu, &wv[wv_offset], ldwv, & z__[jrow + (incol + 1) * z_dim1], ldz); /* L200: */ } } } } /* L210: */ } /* ==== End of ZLAQR5 ==== */ return 0; } /* zlaqr5_ */ /* Subroutine */ int zlarcm_(integer *m, integer *n, doublereal *a, integer * lda, doublecomplex *b, integer *ldb, doublecomplex *c__, integer *ldc, doublereal *rwork) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1; doublecomplex z__1; /* Builtin functions */ double d_imag(doublecomplex *); /* Local variables */ static integer i__, j, l; extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLARCM performs a very simple matrix-matrix multiplication: C := A * B, where A is M by M and real; B is M by N and complex; C is M by N and complex. Arguments ========= M (input) INTEGER The number of rows of the matrix A and of the matrix C. M >= 0. N (input) INTEGER The number of columns and rows of the matrix B and the number of columns of the matrix C. N >= 0. A (input) DOUBLE PRECISION array, dimension (LDA, M) A contains the M by M matrix A. LDA (input) INTEGER The leading dimension of the array A. LDA >=max(1,M). B (input) DOUBLE PRECISION array, dimension (LDB, N) B contains the M by N matrix B. LDB (input) INTEGER The leading dimension of the array B. LDB >=max(1,M). C (input) COMPLEX*16 array, dimension (LDC, N) C contains the M by N matrix C. LDC (input) INTEGER The leading dimension of the array C. LDC >=max(1,M). RWORK (workspace) DOUBLE PRECISION array, dimension (2*M*N) ===================================================================== Quick return if possible. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --rwork; /* Function Body */ if (*m == 0 || *n == 0) { return 0; } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; rwork[(j - 1) * *m + i__] = b[i__3].r; /* L10: */ } /* L20: */ } l = *m * *n + 1; dgemm_("N", "N", m, n, m, &c_b1034, &a[a_offset], lda, &rwork[1], m, & c_b328, &rwork[l], m); i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * c_dim1; i__4 = l + (j - 1) * *m + i__ - 1; c__[i__3].r = rwork[i__4], c__[i__3].i = 0.; /* L30: */ } /* L40: */ } i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { rwork[(j - 1) * *m + i__] = d_imag(&b[i__ + j * b_dim1]); /* L50: */ } /* L60: */ } dgemm_("N", "N", m, n, m, &c_b1034, &a[a_offset], lda, &rwork[1], m, & c_b328, &rwork[l], m); i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * c_dim1; i__4 = i__ + j * c_dim1; d__1 = c__[i__4].r; i__5 = l + (j - 1) * *m + i__ - 1; z__1.r = d__1, z__1.i = rwork[i__5]; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L70: */ } /* L80: */ } return 0; /* End of ZLARCM */ } /* zlarcm_ */ /* Subroutine */ int zlarf_(char *side, integer *m, integer *n, doublecomplex *v, integer *incv, doublecomplex *tau, doublecomplex *c__, integer * ldc, doublecomplex *work) { /* System generated locals */ integer c_dim1, c_offset, i__1; doublecomplex z__1; /* Local variables */ static integer i__; static logical applyleft; extern logical lsame_(char *, char *); static integer lastc; extern /* Subroutine */ int zgerc_(integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lastv; extern integer ilazlc_(integer *, integer *, doublecomplex *, integer *), ilazlr_(integer *, integer *, doublecomplex *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLARF applies a complex elementary reflector H to a complex M-by-N matrix C, from either the left or the right. H is represented in the form H = I - tau * v * v' where tau is a complex scalar and v is a complex vector. If tau = 0, then H is taken to be the unit matrix. To apply H' (the conjugate transpose of H), supply conjg(tau) instead tau. Arguments ========= SIDE (input) CHARACTER*1 = 'L': form H * C = 'R': form C * H M (input) INTEGER The number of rows of the matrix C. N (input) INTEGER The number of columns of the matrix C. V (input) COMPLEX*16 array, dimension (1 + (M-1)*abs(INCV)) if SIDE = 'L' or (1 + (N-1)*abs(INCV)) if SIDE = 'R' The vector v in the representation of H. V is not used if TAU = 0. INCV (input) INTEGER The increment between elements of v. INCV <> 0. TAU (input) COMPLEX*16 The value tau in the representation of H. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX*16 array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R' ===================================================================== */ /* Parameter adjustments */ --v; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ applyleft = lsame_(side, "L"); lastv = 0; lastc = 0; if (tau->r != 0. || tau->i != 0.) { /* Set up variables for scanning V. LASTV begins pointing to the end of V. */ if (applyleft) { lastv = *m; } else { lastv = *n; } if (*incv > 0) { i__ = (lastv - 1) * *incv + 1; } else { i__ = 1; } /* Look for the last non-zero row in V. */ for(;;) { /* while(complicated condition) */ i__1 = i__; if (!(lastv > 0 && (v[i__1].r == 0. && v[i__1].i == 0.))) break; --lastv; i__ -= *incv; } if (applyleft) { /* Scan for the last non-zero column in C(1:lastv,:). */ lastc = ilazlc_(&lastv, n, &c__[c_offset], ldc); } else { /* Scan for the last non-zero row in C(:,1:lastv). */ lastc = ilazlr_(m, &lastv, &c__[c_offset], ldc); } } /* Note that lastc.eq.0 renders the BLAS operations null; no special case is needed at this level. */ if (applyleft) { /* Form H * C */ if (lastv > 0) { /* w(1:lastc,1) := C(1:lastv,1:lastc)' * v(1:lastv,1) */ zgemv_("Conjugate transpose", &lastv, &lastc, &c_b57, &c__[ c_offset], ldc, &v[1], incv, &c_b56, &work[1], &c__1); /* C(1:lastv,1:lastc) := C(...) - v(1:lastv,1) * w(1:lastc,1)' */ z__1.r = -tau->r, z__1.i = -tau->i; zgerc_(&lastv, &lastc, &z__1, &v[1], incv, &work[1], &c__1, &c__[ c_offset], ldc); } } else { /* Form C * H */ if (lastv > 0) { /* w(1:lastc,1) := C(1:lastc,1:lastv) * v(1:lastv,1) */ zgemv_("No transpose", &lastc, &lastv, &c_b57, &c__[c_offset], ldc, &v[1], incv, &c_b56, &work[1], &c__1); /* C(1:lastc,1:lastv) := C(...) - w(1:lastc,1) * v(1:lastv,1)' */ z__1.r = -tau->r, z__1.i = -tau->i; zgerc_(&lastc, &lastv, &z__1, &work[1], &c__1, &v[1], incv, &c__[ c_offset], ldc); } } return 0; /* End of ZLARF */ } /* zlarf_ */ /* Subroutine */ int zlarfb_(char *side, char *trans, char *direct, char * storev, integer *m, integer *n, integer *k, doublecomplex *v, integer *ldv, doublecomplex *t, integer *ldt, doublecomplex *c__, integer * ldc, doublecomplex *work, integer *ldwork) { /* System generated locals */ integer c_dim1, c_offset, t_dim1, t_offset, v_dim1, v_offset, work_dim1, work_offset, i__1, i__2, i__3, i__4, i__5; doublecomplex z__1, z__2; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j; extern logical lsame_(char *, char *); static integer lastc; extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lastv; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), ztrmm_(char *, char *, char *, char * , integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *); extern integer ilazlc_(integer *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int zlacgv_(integer *, doublecomplex *, integer *) ; extern integer ilazlr_(integer *, integer *, doublecomplex *, integer *); static char transt[1]; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLARFB applies a complex block reflector H or its transpose H' to a complex M-by-N matrix C, from either the left or the right. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply H or H' from the Left = 'R': apply H or H' from the Right TRANS (input) CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H' (Conjugate transpose) DIRECT (input) CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV (input) CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise = 'R': Rowwise M (input) INTEGER The number of rows of the matrix C. N (input) INTEGER The number of columns of the matrix C. K (input) INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). V (input) COMPLEX*16 array, dimension (LDV,K) if STOREV = 'C' (LDV,M) if STOREV = 'R' and SIDE = 'L' (LDV,N) if STOREV = 'R' and SIDE = 'R' The matrix V. See further details. LDV (input) INTEGER The leading dimension of the array V. If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M); if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N); if STOREV = 'R', LDV >= K. T (input) COMPLEX*16 array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. LDT (input) INTEGER The leading dimension of the array T. LDT >= K. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by H*C or H'*C or C*H or C*H'. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX*16 array, dimension (LDWORK,K) LDWORK (input) INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M). ===================================================================== Quick return if possible */ /* Parameter adjustments */ v_dim1 = *ldv; v_offset = 1 + v_dim1; v -= v_offset; t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; work_dim1 = *ldwork; work_offset = 1 + work_dim1; work -= work_offset; /* Function Body */ if (*m <= 0 || *n <= 0) { return 0; } if (lsame_(trans, "N")) { *(unsigned char *)transt = 'C'; } else { *(unsigned char *)transt = 'N'; } if (lsame_(storev, "C")) { if (lsame_(direct, "F")) { /* Let V = ( V1 ) (first K rows) ( V2 ) where V1 is unit lower triangular. */ if (lsame_(side, "L")) { /* Form H * C or H' * C where C = ( C1 ) ( C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlr_(m, k, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlc_(&lastv, n, &c__[c_offset], ldc); /* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) W := C1' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1], &c__1); zlacgv_(&lastc, &work[j * work_dim1 + 1], &c__1); /* L10: */ } /* W := W * V1 */ ztrmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, & c_b57, &v[v_offset], ldv, &work[work_offset], ldwork); if (lastv > *k) { /* W := W + C2'*V2 */ i__1 = lastv - *k; zgemm_("Conjugate transpose", "No transpose", &lastc, k, & i__1, &c_b57, &c__[*k + 1 + c_dim1], ldc, &v[*k + 1 + v_dim1], ldv, &c_b57, &work[work_offset], ldwork); } /* W := W * T' or W * T */ ztrmm_("Right", "Upper", transt, "Non-unit", &lastc, k, & c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - V * W' */ if (*m > *k) { /* C2 := C2 - V2 * W' */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", &i__1, & lastc, k, &z__1, &v[*k + 1 + v_dim1], ldv, &work[ work_offset], ldwork, &c_b57, &c__[*k + 1 + c_dim1], ldc); } /* W := W * V1' */ ztrmm_("Right", "Lower", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[v_offset], ldv, &work[ work_offset], ldwork); /* C1 := C1 - W' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = j + i__ * c_dim1; i__4 = j + i__ * c_dim1; d_cnjg(&z__2, &work[i__ + j * work_dim1]); z__1.r = c__[i__4].r - z__2.r, z__1.i = c__[i__4].i - z__2.i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L20: */ } /* L30: */ } } else if (lsame_(side, "R")) { /* Form C * H or C * H' where C = ( C1 C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlr_(n, k, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlr_(m, &lastv, &c__[c_offset], ldc); /* W := C * V = (C1*V1 + C2*V2) (stored in WORK) W := C1 */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[j * c_dim1 + 1], &c__1, &work[j * work_dim1 + 1], &c__1); /* L40: */ } /* W := W * V1 */ ztrmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, & c_b57, &v[v_offset], ldv, &work[work_offset], ldwork); if (lastv > *k) { /* W := W + C2 * V2 */ i__1 = lastv - *k; zgemm_("No transpose", "No transpose", &lastc, k, &i__1, & c_b57, &c__[(*k + 1) * c_dim1 + 1], ldc, &v[*k + 1 + v_dim1], ldv, &c_b57, &work[work_offset], ldwork); } /* W := W * T or W * T' */ ztrmm_("Right", "Upper", trans, "Non-unit", &lastc, k, &c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - W * V' */ if (lastv > *k) { /* C2 := C2 - W * V2' */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", &lastc, & i__1, k, &z__1, &work[work_offset], ldwork, &v[*k + 1 + v_dim1], ldv, &c_b57, &c__[(*k + 1) * c_dim1 + 1], ldc); } /* W := W * V1' */ ztrmm_("Right", "Lower", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[v_offset], ldv, &work[ work_offset], ldwork); /* C1 := C1 - W */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * c_dim1; i__4 = i__ + j * c_dim1; i__5 = i__ + j * work_dim1; z__1.r = c__[i__4].r - work[i__5].r, z__1.i = c__[ i__4].i - work[i__5].i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L50: */ } /* L60: */ } } } else { /* Let V = ( V1 ) ( V2 ) (last K rows) where V2 is unit upper triangular. */ if (lsame_(side, "L")) { /* Form H * C or H' * C where C = ( C1 ) ( C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlr_(m, k, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlc_(&lastv, n, &c__[c_offset], ldc); /* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) W := C2' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[lastv - *k + j + c_dim1], ldc, &work[ j * work_dim1 + 1], &c__1); zlacgv_(&lastc, &work[j * work_dim1 + 1], &c__1); /* L70: */ } /* W := W * V2 */ ztrmm_("Right", "Upper", "No transpose", "Unit", &lastc, k, & c_b57, &v[lastv - *k + 1 + v_dim1], ldv, &work[ work_offset], ldwork); if (lastv > *k) { /* W := W + C1'*V1 */ i__1 = lastv - *k; zgemm_("Conjugate transpose", "No transpose", &lastc, k, & i__1, &c_b57, &c__[c_offset], ldc, &v[v_offset], ldv, &c_b57, &work[work_offset], ldwork); } /* W := W * T' or W * T */ ztrmm_("Right", "Lower", transt, "Non-unit", &lastc, k, & c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - V * W' */ if (lastv > *k) { /* C1 := C1 - V1 * W' */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", &i__1, & lastc, k, &z__1, &v[v_offset], ldv, &work[ work_offset], ldwork, &c_b57, &c__[c_offset], ldc); } /* W := W * V2' */ ztrmm_("Right", "Upper", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[lastv - *k + 1 + v_dim1], ldv, & work[work_offset], ldwork); /* C2 := C2 - W' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = lastv - *k + j + i__ * c_dim1; i__4 = lastv - *k + j + i__ * c_dim1; d_cnjg(&z__2, &work[i__ + j * work_dim1]); z__1.r = c__[i__4].r - z__2.r, z__1.i = c__[i__4].i - z__2.i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L80: */ } /* L90: */ } } else if (lsame_(side, "R")) { /* Form C * H or C * H' where C = ( C1 C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlr_(n, k, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlr_(m, &lastv, &c__[c_offset], ldc); /* W := C * V = (C1*V1 + C2*V2) (stored in WORK) W := C2 */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[(lastv - *k + j) * c_dim1 + 1], &c__1, &work[j * work_dim1 + 1], &c__1); /* L100: */ } /* W := W * V2 */ ztrmm_("Right", "Upper", "No transpose", "Unit", &lastc, k, & c_b57, &v[lastv - *k + 1 + v_dim1], ldv, &work[ work_offset], ldwork); if (lastv > *k) { /* W := W + C1 * V1 */ i__1 = lastv - *k; zgemm_("No transpose", "No transpose", &lastc, k, &i__1, & c_b57, &c__[c_offset], ldc, &v[v_offset], ldv, & c_b57, &work[work_offset], ldwork); } /* W := W * T or W * T' */ ztrmm_("Right", "Lower", trans, "Non-unit", &lastc, k, &c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - W * V' */ if (lastv > *k) { /* C1 := C1 - W * V1' */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", &lastc, & i__1, k, &z__1, &work[work_offset], ldwork, &v[ v_offset], ldv, &c_b57, &c__[c_offset], ldc); } /* W := W * V2' */ ztrmm_("Right", "Upper", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[lastv - *k + 1 + v_dim1], ldv, & work[work_offset], ldwork); /* C2 := C2 - W */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + (lastv - *k + j) * c_dim1; i__4 = i__ + (lastv - *k + j) * c_dim1; i__5 = i__ + j * work_dim1; z__1.r = c__[i__4].r - work[i__5].r, z__1.i = c__[ i__4].i - work[i__5].i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L110: */ } /* L120: */ } } } } else if (lsame_(storev, "R")) { if (lsame_(direct, "F")) { /* Let V = ( V1 V2 ) (V1: first K columns) where V1 is unit upper triangular. */ if (lsame_(side, "L")) { /* Form H * C or H' * C where C = ( C1 ) ( C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlc_(k, m, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlc_(&lastv, n, &c__[c_offset], ldc); /* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) W := C1' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1], &c__1); zlacgv_(&lastc, &work[j * work_dim1 + 1], &c__1); /* L130: */ } /* W := W * V1' */ ztrmm_("Right", "Upper", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[v_offset], ldv, &work[ work_offset], ldwork); if (lastv > *k) { /* W := W + C2'*V2' */ i__1 = lastv - *k; zgemm_("Conjugate transpose", "Conjugate transpose", & lastc, k, &i__1, &c_b57, &c__[*k + 1 + c_dim1], ldc, &v[(*k + 1) * v_dim1 + 1], ldv, &c_b57, & work[work_offset], ldwork) ; } /* W := W * T' or W * T */ ztrmm_("Right", "Upper", transt, "Non-unit", &lastc, k, & c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - V' * W' */ if (lastv > *k) { /* C2 := C2 - V2' * W' */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("Conjugate transpose", "Conjugate transpose", & i__1, &lastc, k, &z__1, &v[(*k + 1) * v_dim1 + 1], ldv, &work[work_offset], ldwork, &c_b57, &c__[*k + 1 + c_dim1], ldc); } /* W := W * V1 */ ztrmm_("Right", "Upper", "No transpose", "Unit", &lastc, k, & c_b57, &v[v_offset], ldv, &work[work_offset], ldwork); /* C1 := C1 - W' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = j + i__ * c_dim1; i__4 = j + i__ * c_dim1; d_cnjg(&z__2, &work[i__ + j * work_dim1]); z__1.r = c__[i__4].r - z__2.r, z__1.i = c__[i__4].i - z__2.i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L140: */ } /* L150: */ } } else if (lsame_(side, "R")) { /* Form C * H or C * H' where C = ( C1 C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlc_(k, n, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlr_(m, &lastv, &c__[c_offset], ldc); /* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) W := C1 */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[j * c_dim1 + 1], &c__1, &work[j * work_dim1 + 1], &c__1); /* L160: */ } /* W := W * V1' */ ztrmm_("Right", "Upper", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[v_offset], ldv, &work[ work_offset], ldwork); if (lastv > *k) { /* W := W + C2 * V2' */ i__1 = lastv - *k; zgemm_("No transpose", "Conjugate transpose", &lastc, k, & i__1, &c_b57, &c__[(*k + 1) * c_dim1 + 1], ldc, & v[(*k + 1) * v_dim1 + 1], ldv, &c_b57, &work[ work_offset], ldwork); } /* W := W * T or W * T' */ ztrmm_("Right", "Upper", trans, "Non-unit", &lastc, k, &c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - W * V */ if (lastv > *k) { /* C2 := C2 - W * V2 */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "No transpose", &lastc, &i__1, k, & z__1, &work[work_offset], ldwork, &v[(*k + 1) * v_dim1 + 1], ldv, &c_b57, &c__[(*k + 1) * c_dim1 + 1], ldc); } /* W := W * V1 */ ztrmm_("Right", "Upper", "No transpose", "Unit", &lastc, k, & c_b57, &v[v_offset], ldv, &work[work_offset], ldwork); /* C1 := C1 - W */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * c_dim1; i__4 = i__ + j * c_dim1; i__5 = i__ + j * work_dim1; z__1.r = c__[i__4].r - work[i__5].r, z__1.i = c__[ i__4].i - work[i__5].i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L170: */ } /* L180: */ } } } else { /* Let V = ( V1 V2 ) (V2: last K columns) where V2 is unit lower triangular. */ if (lsame_(side, "L")) { /* Form H * C or H' * C where C = ( C1 ) ( C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlc_(k, m, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlc_(&lastv, n, &c__[c_offset], ldc); /* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) W := C2' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[lastv - *k + j + c_dim1], ldc, &work[ j * work_dim1 + 1], &c__1); zlacgv_(&lastc, &work[j * work_dim1 + 1], &c__1); /* L190: */ } /* W := W * V2' */ ztrmm_("Right", "Lower", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[(lastv - *k + 1) * v_dim1 + 1], ldv, &work[work_offset], ldwork); if (lastv > *k) { /* W := W + C1'*V1' */ i__1 = lastv - *k; zgemm_("Conjugate transpose", "Conjugate transpose", & lastc, k, &i__1, &c_b57, &c__[c_offset], ldc, &v[ v_offset], ldv, &c_b57, &work[work_offset], ldwork); } /* W := W * T' or W * T */ ztrmm_("Right", "Lower", transt, "Non-unit", &lastc, k, & c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - V' * W' */ if (lastv > *k) { /* C1 := C1 - V1' * W' */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("Conjugate transpose", "Conjugate transpose", & i__1, &lastc, k, &z__1, &v[v_offset], ldv, &work[ work_offset], ldwork, &c_b57, &c__[c_offset], ldc); } /* W := W * V2 */ ztrmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, & c_b57, &v[(lastv - *k + 1) * v_dim1 + 1], ldv, &work[ work_offset], ldwork); /* C2 := C2 - W' */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = lastv - *k + j + i__ * c_dim1; i__4 = lastv - *k + j + i__ * c_dim1; d_cnjg(&z__2, &work[i__ + j * work_dim1]); z__1.r = c__[i__4].r - z__2.r, z__1.i = c__[i__4].i - z__2.i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L200: */ } /* L210: */ } } else if (lsame_(side, "R")) { /* Form C * H or C * H' where C = ( C1 C2 ) Computing MAX */ i__1 = *k, i__2 = ilazlc_(k, n, &v[v_offset], ldv); lastv = max(i__1,i__2); lastc = ilazlr_(m, &lastv, &c__[c_offset], ldc); /* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) W := C2 */ i__1 = *k; for (j = 1; j <= i__1; ++j) { zcopy_(&lastc, &c__[(lastv - *k + j) * c_dim1 + 1], &c__1, &work[j * work_dim1 + 1], &c__1); /* L220: */ } /* W := W * V2' */ ztrmm_("Right", "Lower", "Conjugate transpose", "Unit", & lastc, k, &c_b57, &v[(lastv - *k + 1) * v_dim1 + 1], ldv, &work[work_offset], ldwork); if (lastv > *k) { /* W := W + C1 * V1' */ i__1 = lastv - *k; zgemm_("No transpose", "Conjugate transpose", &lastc, k, & i__1, &c_b57, &c__[c_offset], ldc, &v[v_offset], ldv, &c_b57, &work[work_offset], ldwork); } /* W := W * T or W * T' */ ztrmm_("Right", "Lower", trans, "Non-unit", &lastc, k, &c_b57, &t[t_offset], ldt, &work[work_offset], ldwork); /* C := C - W * V */ if (lastv > *k) { /* C1 := C1 - W * V1 */ i__1 = lastv - *k; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "No transpose", &lastc, &i__1, k, & z__1, &work[work_offset], ldwork, &v[v_offset], ldv, &c_b57, &c__[c_offset], ldc); } /* W := W * V2 */ ztrmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, & c_b57, &v[(lastv - *k + 1) * v_dim1 + 1], ldv, &work[ work_offset], ldwork); /* C1 := C1 - W */ i__1 = *k; for (j = 1; j <= i__1; ++j) { i__2 = lastc; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + (lastv - *k + j) * c_dim1; i__4 = i__ + (lastv - *k + j) * c_dim1; i__5 = i__ + j * work_dim1; z__1.r = c__[i__4].r - work[i__5].r, z__1.i = c__[ i__4].i - work[i__5].i; c__[i__3].r = z__1.r, c__[i__3].i = z__1.i; /* L230: */ } /* L240: */ } } } } return 0; /* End of ZLARFB */ } /* zlarfb_ */ /* Subroutine */ int zlarfg_(integer *n, doublecomplex *alpha, doublecomplex * x, integer *incx, doublecomplex *tau) { /* System generated locals */ integer i__1; doublereal d__1, d__2; doublecomplex z__1, z__2; /* Builtin functions */ double d_imag(doublecomplex *), d_sign(doublereal *, doublereal *); /* Local variables */ static integer j, knt; static doublereal beta, alphi, alphr; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *); static doublereal xnorm; extern doublereal dlapy3_(doublereal *, doublereal *, doublereal *), dznrm2_(integer *, doublecomplex *, integer *), dlamch_(char *); static doublereal safmin; extern /* Subroutine */ int zdscal_(integer *, doublereal *, doublecomplex *, integer *); static doublereal rsafmn; extern /* Double Complex */ VOID zladiv_(doublecomplex *, doublecomplex *, doublecomplex *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLARFG generates a complex elementary reflector H of order n, such that H' * ( alpha ) = ( beta ), H' * H = I. ( x ) ( 0 ) where alpha and beta are scalars, with beta real, and x is an (n-1)-element complex vector. H is represented in the form H = I - tau * ( 1 ) * ( 1 v' ) , ( v ) where tau is a complex scalar and v is a complex (n-1)-element vector. Note that H is not hermitian. If the elements of x are all zero and alpha is real, then tau = 0 and H is taken to be the unit matrix. Otherwise 1 <= real(tau) <= 2 and abs(tau-1) <= 1 . Arguments ========= N (input) INTEGER The order of the elementary reflector. ALPHA (input/output) COMPLEX*16 On entry, the value alpha. On exit, it is overwritten with the value beta. X (input/output) COMPLEX*16 array, dimension (1+(N-2)*abs(INCX)) On entry, the vector x. On exit, it is overwritten with the vector v. INCX (input) INTEGER The increment between elements of X. INCX > 0. TAU (output) COMPLEX*16 The value tau. ===================================================================== */ /* Parameter adjustments */ --x; /* Function Body */ if (*n <= 0) { tau->r = 0., tau->i = 0.; return 0; } i__1 = *n - 1; xnorm = dznrm2_(&i__1, &x[1], incx); alphr = alpha->r; alphi = d_imag(alpha); if (xnorm == 0. && alphi == 0.) { /* H = I */ tau->r = 0., tau->i = 0.; } else { /* general case */ d__1 = dlapy3_(&alphr, &alphi, &xnorm); beta = -d_sign(&d__1, &alphr); safmin = SAFEMINIMUM / EPSILON; rsafmn = 1. / safmin; knt = 0; if (abs(beta) < safmin) { /* XNORM, BETA may be inaccurate; scale X and recompute them */ L10: ++knt; i__1 = *n - 1; zdscal_(&i__1, &rsafmn, &x[1], incx); beta *= rsafmn; alphi *= rsafmn; alphr *= rsafmn; if (abs(beta) < safmin) { goto L10; } /* New BETA is at most 1, at least SAFMIN */ i__1 = *n - 1; xnorm = dznrm2_(&i__1, &x[1], incx); z__1.r = alphr, z__1.i = alphi; alpha->r = z__1.r, alpha->i = z__1.i; d__1 = dlapy3_(&alphr, &alphi, &xnorm); beta = -d_sign(&d__1, &alphr); } d__1 = (beta - alphr) / beta; d__2 = -alphi / beta; z__1.r = d__1, z__1.i = d__2; tau->r = z__1.r, tau->i = z__1.i; z__2.r = alpha->r - beta, z__2.i = alpha->i; zladiv_(&z__1, &c_b57, &z__2); alpha->r = z__1.r, alpha->i = z__1.i; i__1 = *n - 1; zscal_(&i__1, alpha, &x[1], incx); /* If ALPHA is subnormal, it may lose relative accuracy */ i__1 = knt; for (j = 1; j <= i__1; ++j) { beta *= safmin; /* L20: */ } alpha->r = beta, alpha->i = 0.; } return 0; /* End of ZLARFG */ } /* zlarfg_ */ /* Subroutine */ int zlarft_(char *direct, char *storev, integer *n, integer * k, doublecomplex *v, integer *ldv, doublecomplex *tau, doublecomplex * t, integer *ldt) { /* System generated locals */ integer t_dim1, t_offset, v_dim1, v_offset, i__1, i__2, i__3, i__4; doublecomplex z__1; /* Local variables */ static integer i__, j, prevlastv; static doublecomplex vii; extern logical lsame_(char *, char *); extern /* Subroutine */ int zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lastv; extern /* Subroutine */ int ztrmv_(char *, char *, char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlacgv_(integer *, doublecomplex *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLARFT forms the triangular factor T of a complex block reflector H of order n, which is defined as a product of k elementary reflectors. If DIRECT = 'F', H = H(1) H(2) . . . H(k) and T is upper triangular; If DIRECT = 'B', H = H(k) . . . H(2) H(1) and T is lower triangular. If STOREV = 'C', the vector which defines the elementary reflector H(i) is stored in the i-th column of the array V, and H = I - V * T * V' If STOREV = 'R', the vector which defines the elementary reflector H(i) is stored in the i-th row of the array V, and H = I - V' * T * V Arguments ========= DIRECT (input) CHARACTER*1 Specifies the order in which the elementary reflectors are multiplied to form the block reflector: = 'F': H = H(1) H(2) . . . H(k) (Forward) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV (input) CHARACTER*1 Specifies how the vectors which define the elementary reflectors are stored (see also Further Details): = 'C': columnwise = 'R': rowwise N (input) INTEGER The order of the block reflector H. N >= 0. K (input) INTEGER The order of the triangular factor T (= the number of elementary reflectors). K >= 1. V (input/output) COMPLEX*16 array, dimension (LDV,K) if STOREV = 'C' (LDV,N) if STOREV = 'R' The matrix V. See further details. LDV (input) INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= max(1,N); if STOREV = 'R', LDV >= K. TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i). T (output) COMPLEX*16 array, dimension (LDT,K) The k by k triangular factor T of the block reflector. If DIRECT = 'F', T is upper triangular; if DIRECT = 'B', T is lower triangular. The rest of the array is not used. LDT (input) INTEGER The leading dimension of the array T. LDT >= K. Further Details =============== The shape of the matrix V and the storage of the vectors which define the H(i) is best illustrated by the following example with n = 5 and k = 3. The elements equal to 1 are not stored; the corresponding array elements are modified but restored on exit. The rest of the array is not used. DIRECT = 'F' and STOREV = 'C': DIRECT = 'F' and STOREV = 'R': V = ( 1 ) V = ( 1 v1 v1 v1 v1 ) ( v1 1 ) ( 1 v2 v2 v2 ) ( v1 v2 1 ) ( 1 v3 v3 ) ( v1 v2 v3 ) ( v1 v2 v3 ) DIRECT = 'B' and STOREV = 'C': DIRECT = 'B' and STOREV = 'R': V = ( v1 v2 v3 ) V = ( v1 v1 1 ) ( v1 v2 v3 ) ( v2 v2 v2 1 ) ( 1 v2 v3 ) ( v3 v3 v3 v3 1 ) ( 1 v3 ) ( 1 ) ===================================================================== Quick return if possible */ /* Parameter adjustments */ v_dim1 = *ldv; v_offset = 1 + v_dim1; v -= v_offset; --tau; t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; /* Function Body */ if (*n == 0) { return 0; } if (lsame_(direct, "F")) { prevlastv = *n; i__1 = *k; for (i__ = 1; i__ <= i__1; ++i__) { prevlastv = max(prevlastv,i__); i__2 = i__; if (tau[i__2].r == 0. && tau[i__2].i == 0.) { /* H(i) = I */ i__2 = i__; for (j = 1; j <= i__2; ++j) { i__3 = j + i__ * t_dim1; t[i__3].r = 0., t[i__3].i = 0.; /* L10: */ } } else { /* general case */ i__2 = i__ + i__ * v_dim1; vii.r = v[i__2].r, vii.i = v[i__2].i; i__2 = i__ + i__ * v_dim1; v[i__2].r = 1., v[i__2].i = 0.; if (lsame_(storev, "C")) { /* Skip any trailing zeros. */ i__2 = i__ + 1; for (lastv = *n; lastv >= i__2; --lastv) { i__3 = lastv + i__ * v_dim1; if (v[i__3].r != 0. || v[i__3].i != 0.) { goto L15; } } L15: j = min(lastv,prevlastv); /* T(1:i-1,i) := - tau(i) * V(i:j,1:i-1)' * V(i:j,i) */ i__2 = j - i__ + 1; i__3 = i__ - 1; i__4 = i__; z__1.r = -tau[i__4].r, z__1.i = -tau[i__4].i; zgemv_("Conjugate transpose", &i__2, &i__3, &z__1, &v[i__ + v_dim1], ldv, &v[i__ + i__ * v_dim1], &c__1, & c_b56, &t[i__ * t_dim1 + 1], &c__1); } else { /* Skip any trailing zeros. */ i__2 = i__ + 1; for (lastv = *n; lastv >= i__2; --lastv) { i__3 = i__ + lastv * v_dim1; if (v[i__3].r != 0. || v[i__3].i != 0.) { goto L16; } } L16: j = min(lastv,prevlastv); /* T(1:i-1,i) := - tau(i) * V(1:i-1,i:j) * V(i,i:j)' */ if (i__ < j) { i__2 = j - i__; zlacgv_(&i__2, &v[i__ + (i__ + 1) * v_dim1], ldv); } i__2 = i__ - 1; i__3 = j - i__ + 1; i__4 = i__; z__1.r = -tau[i__4].r, z__1.i = -tau[i__4].i; zgemv_("No transpose", &i__2, &i__3, &z__1, &v[i__ * v_dim1 + 1], ldv, &v[i__ + i__ * v_dim1], ldv, & c_b56, &t[i__ * t_dim1 + 1], &c__1); if (i__ < j) { i__2 = j - i__; zlacgv_(&i__2, &v[i__ + (i__ + 1) * v_dim1], ldv); } } i__2 = i__ + i__ * v_dim1; v[i__2].r = vii.r, v[i__2].i = vii.i; /* T(1:i-1,i) := T(1:i-1,1:i-1) * T(1:i-1,i) */ i__2 = i__ - 1; ztrmv_("Upper", "No transpose", "Non-unit", &i__2, &t[ t_offset], ldt, &t[i__ * t_dim1 + 1], &c__1); i__2 = i__ + i__ * t_dim1; i__3 = i__; t[i__2].r = tau[i__3].r, t[i__2].i = tau[i__3].i; if (i__ > 1) { prevlastv = max(prevlastv,lastv); } else { prevlastv = lastv; } } /* L20: */ } } else { prevlastv = 1; for (i__ = *k; i__ >= 1; --i__) { i__1 = i__; if (tau[i__1].r == 0. && tau[i__1].i == 0.) { /* H(i) = I */ i__1 = *k; for (j = i__; j <= i__1; ++j) { i__2 = j + i__ * t_dim1; t[i__2].r = 0., t[i__2].i = 0.; /* L30: */ } } else { /* general case */ if (i__ < *k) { if (lsame_(storev, "C")) { i__1 = *n - *k + i__ + i__ * v_dim1; vii.r = v[i__1].r, vii.i = v[i__1].i; i__1 = *n - *k + i__ + i__ * v_dim1; v[i__1].r = 1., v[i__1].i = 0.; /* Skip any leading zeros. */ i__1 = i__ - 1; for (lastv = 1; lastv <= i__1; ++lastv) { i__2 = lastv + i__ * v_dim1; if (v[i__2].r != 0. || v[i__2].i != 0.) { goto L35; } } L35: j = max(lastv,prevlastv); /* T(i+1:k,i) := - tau(i) * V(j:n-k+i,i+1:k)' * V(j:n-k+i,i) */ i__1 = *n - *k + i__ - j + 1; i__2 = *k - i__; i__3 = i__; z__1.r = -tau[i__3].r, z__1.i = -tau[i__3].i; zgemv_("Conjugate transpose", &i__1, &i__2, &z__1, &v[ j + (i__ + 1) * v_dim1], ldv, &v[j + i__ * v_dim1], &c__1, &c_b56, &t[i__ + 1 + i__ * t_dim1], &c__1); i__1 = *n - *k + i__ + i__ * v_dim1; v[i__1].r = vii.r, v[i__1].i = vii.i; } else { i__1 = i__ + (*n - *k + i__) * v_dim1; vii.r = v[i__1].r, vii.i = v[i__1].i; i__1 = i__ + (*n - *k + i__) * v_dim1; v[i__1].r = 1., v[i__1].i = 0.; /* Skip any leading zeros. */ i__1 = i__ - 1; for (lastv = 1; lastv <= i__1; ++lastv) { i__2 = i__ + lastv * v_dim1; if (v[i__2].r != 0. || v[i__2].i != 0.) { goto L36; } } L36: j = max(lastv,prevlastv); /* T(i+1:k,i) := - tau(i) * V(i+1:k,j:n-k+i) * V(i,j:n-k+i)' */ i__1 = *n - *k + i__ - 1 - j + 1; zlacgv_(&i__1, &v[i__ + j * v_dim1], ldv); i__1 = *k - i__; i__2 = *n - *k + i__ - j + 1; i__3 = i__; z__1.r = -tau[i__3].r, z__1.i = -tau[i__3].i; zgemv_("No transpose", &i__1, &i__2, &z__1, &v[i__ + 1 + j * v_dim1], ldv, &v[i__ + j * v_dim1], ldv, &c_b56, &t[i__ + 1 + i__ * t_dim1], & c__1); i__1 = *n - *k + i__ - 1 - j + 1; zlacgv_(&i__1, &v[i__ + j * v_dim1], ldv); i__1 = i__ + (*n - *k + i__) * v_dim1; v[i__1].r = vii.r, v[i__1].i = vii.i; } /* T(i+1:k,i) := T(i+1:k,i+1:k) * T(i+1:k,i) */ i__1 = *k - i__; ztrmv_("Lower", "No transpose", "Non-unit", &i__1, &t[i__ + 1 + (i__ + 1) * t_dim1], ldt, &t[i__ + 1 + i__ * t_dim1], &c__1) ; if (i__ > 1) { prevlastv = min(prevlastv,lastv); } else { prevlastv = lastv; } } i__1 = i__ + i__ * t_dim1; i__2 = i__; t[i__1].r = tau[i__2].r, t[i__1].i = tau[i__2].i; } /* L40: */ } } return 0; /* End of ZLARFT */ } /* zlarft_ */ /* Subroutine */ int zlartg_(doublecomplex *f, doublecomplex *g, doublereal * cs, doublecomplex *sn, doublecomplex *r__) { /* System generated locals */ integer i__1; doublereal d__1, d__2, d__3, d__4, d__5, d__6, d__7, d__8, d__9, d__10; doublecomplex z__1, z__2, z__3; /* Builtin functions */ double log(doublereal), pow_di(doublereal *, integer *), d_imag( doublecomplex *), sqrt(doublereal); void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static doublereal d__; static integer i__; static doublereal f2, g2; static doublecomplex ff; static doublereal di, dr; static doublecomplex fs, gs; static doublereal f2s, g2s, eps, scale; static integer count; static doublereal safmn2; extern doublereal dlapy2_(doublereal *, doublereal *); static doublereal safmx2; static doublereal safmin; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLARTG generates a plane rotation so that [ CS SN ] [ F ] [ R ] [ __ ] . [ ] = [ ] where CS**2 + |SN|**2 = 1. [ -SN CS ] [ G ] [ 0 ] This is a faster version of the BLAS1 routine ZROTG, except for the following differences: F and G are unchanged on return. If G=0, then CS=1 and SN=0. If F=0, then CS=0 and SN is chosen so that R is real. Arguments ========= F (input) COMPLEX*16 The first component of vector to be rotated. G (input) COMPLEX*16 The second component of vector to be rotated. CS (output) DOUBLE PRECISION The cosine of the rotation. SN (output) COMPLEX*16 The sine of the rotation. R (output) COMPLEX*16 The nonzero component of the rotated vector. Further Details ======= ======= 3-5-96 - Modified with a new algorithm by W. Kahan and J. Demmel This version has a few statements commented out for thread safety (machine parameters are computed on each entry). 10 feb 03, SJH. ===================================================================== LOGICAL FIRST SAVE FIRST, SAFMX2, SAFMIN, SAFMN2 DATA FIRST / .TRUE. / IF( FIRST ) THEN */ safmin = SAFEMINIMUM; eps = EPSILON; d__1 = BASE; i__1 = (integer) (log(safmin / eps) / log(BASE) / 2.); safmn2 = pow_di(&d__1, &i__1); safmx2 = 1. / safmn2; /* FIRST = .FALSE. END IF Computing MAX Computing MAX */ d__7 = (d__1 = f->r, abs(d__1)), d__8 = (d__2 = d_imag(f), abs(d__2)); /* Computing MAX */ d__9 = (d__3 = g->r, abs(d__3)), d__10 = (d__4 = d_imag(g), abs(d__4)); d__5 = max(d__7,d__8), d__6 = max(d__9,d__10); scale = max(d__5,d__6); fs.r = f->r, fs.i = f->i; gs.r = g->r, gs.i = g->i; count = 0; if (scale >= safmx2) { L10: ++count; z__1.r = safmn2 * fs.r, z__1.i = safmn2 * fs.i; fs.r = z__1.r, fs.i = z__1.i; z__1.r = safmn2 * gs.r, z__1.i = safmn2 * gs.i; gs.r = z__1.r, gs.i = z__1.i; scale *= safmn2; if (scale >= safmx2) { goto L10; } } else if (scale <= safmn2) { if (g->r == 0. && g->i == 0.) { *cs = 1.; sn->r = 0., sn->i = 0.; r__->r = f->r, r__->i = f->i; return 0; } L20: --count; z__1.r = safmx2 * fs.r, z__1.i = safmx2 * fs.i; fs.r = z__1.r, fs.i = z__1.i; z__1.r = safmx2 * gs.r, z__1.i = safmx2 * gs.i; gs.r = z__1.r, gs.i = z__1.i; scale *= safmx2; if (scale <= safmn2) { goto L20; } } /* Computing 2nd power */ d__1 = fs.r; /* Computing 2nd power */ d__2 = d_imag(&fs); f2 = d__1 * d__1 + d__2 * d__2; /* Computing 2nd power */ d__1 = gs.r; /* Computing 2nd power */ d__2 = d_imag(&gs); g2 = d__1 * d__1 + d__2 * d__2; if (f2 <= max(g2,1.) * safmin) { /* This is a rare case: F is very small. */ if (f->r == 0. && f->i == 0.) { *cs = 0.; d__2 = g->r; d__3 = d_imag(g); d__1 = dlapy2_(&d__2, &d__3); r__->r = d__1, r__->i = 0.; /* Do complex/real division explicitly with two real divisions */ d__1 = gs.r; d__2 = d_imag(&gs); d__ = dlapy2_(&d__1, &d__2); d__1 = gs.r / d__; d__2 = -d_imag(&gs) / d__; z__1.r = d__1, z__1.i = d__2; sn->r = z__1.r, sn->i = z__1.i; return 0; } d__1 = fs.r; d__2 = d_imag(&fs); f2s = dlapy2_(&d__1, &d__2); /* G2 and G2S are accurate G2 is at least SAFMIN, and G2S is at least SAFMN2 */ g2s = sqrt(g2); /* Error in CS from underflow in F2S is at most UNFL / SAFMN2 .lt. sqrt(UNFL*EPS) .lt. EPS If MAX(G2,ONE)=G2, then F2 .lt. G2*SAFMIN, and so CS .lt. sqrt(SAFMIN) If MAX(G2,ONE)=ONE, then F2 .lt. SAFMIN and so CS .lt. sqrt(SAFMIN)/SAFMN2 = sqrt(EPS) Therefore, CS = F2S/G2S / sqrt( 1 + (F2S/G2S)**2 ) = F2S/G2S */ *cs = f2s / g2s; /* Make sure abs(FF) = 1 Do complex/real division explicitly with 2 real divisions Computing MAX */ d__3 = (d__1 = f->r, abs(d__1)), d__4 = (d__2 = d_imag(f), abs(d__2)); if (max(d__3,d__4) > 1.) { d__1 = f->r; d__2 = d_imag(f); d__ = dlapy2_(&d__1, &d__2); d__1 = f->r / d__; d__2 = d_imag(f) / d__; z__1.r = d__1, z__1.i = d__2; ff.r = z__1.r, ff.i = z__1.i; } else { dr = safmx2 * f->r; di = safmx2 * d_imag(f); d__ = dlapy2_(&dr, &di); d__1 = dr / d__; d__2 = di / d__; z__1.r = d__1, z__1.i = d__2; ff.r = z__1.r, ff.i = z__1.i; } d__1 = gs.r / g2s; d__2 = -d_imag(&gs) / g2s; z__2.r = d__1, z__2.i = d__2; z__1.r = ff.r * z__2.r - ff.i * z__2.i, z__1.i = ff.r * z__2.i + ff.i * z__2.r; sn->r = z__1.r, sn->i = z__1.i; z__2.r = *cs * f->r, z__2.i = *cs * f->i; z__3.r = sn->r * g->r - sn->i * g->i, z__3.i = sn->r * g->i + sn->i * g->r; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; r__->r = z__1.r, r__->i = z__1.i; } else { /* This is the most common case. Neither F2 nor F2/G2 are less than SAFMIN F2S cannot overflow, and it is accurate */ f2s = sqrt(g2 / f2 + 1.); /* Do the F2S(real)*FS(complex) multiply with two real multiplies */ d__1 = f2s * fs.r; d__2 = f2s * d_imag(&fs); z__1.r = d__1, z__1.i = d__2; r__->r = z__1.r, r__->i = z__1.i; *cs = 1. / f2s; d__ = f2 + g2; /* Do complex/real division explicitly with two real divisions */ d__1 = r__->r / d__; d__2 = d_imag(r__) / d__; z__1.r = d__1, z__1.i = d__2; sn->r = z__1.r, sn->i = z__1.i; d_cnjg(&z__2, &gs); z__1.r = sn->r * z__2.r - sn->i * z__2.i, z__1.i = sn->r * z__2.i + sn->i * z__2.r; sn->r = z__1.r, sn->i = z__1.i; if (count != 0) { if (count > 0) { i__1 = count; for (i__ = 1; i__ <= i__1; ++i__) { z__1.r = safmx2 * r__->r, z__1.i = safmx2 * r__->i; r__->r = z__1.r, r__->i = z__1.i; /* L30: */ } } else { i__1 = -count; for (i__ = 1; i__ <= i__1; ++i__) { z__1.r = safmn2 * r__->r, z__1.i = safmn2 * r__->i; r__->r = z__1.r, r__->i = z__1.i; /* L40: */ } } } } return 0; /* End of ZLARTG */ } /* zlartg_ */ /* Subroutine */ int zlascl_(char *type__, integer *kl, integer *ku, doublereal *cfrom, doublereal *cto, integer *m, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5; doublecomplex z__1; /* Local variables */ static integer i__, j, k1, k2, k3, k4; static doublereal mul, cto1; static logical done; static doublereal ctoc; extern logical lsame_(char *, char *); static integer itype; static doublereal cfrom1; static doublereal cfromc; extern logical disnan_(doublereal *); extern /* Subroutine */ int xerbla_(char *, integer *); static doublereal bignum, smlnum; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLASCL multiplies the M by N complex matrix A by the real scalar CTO/CFROM. This is done without over/underflow as long as the final result CTO*A(I,J)/CFROM does not over/underflow. TYPE specifies that A may be full, upper triangular, lower triangular, upper Hessenberg, or banded. Arguments ========= TYPE (input) CHARACTER*1 TYPE indices the storage type of the input matrix. = 'G': A is a full matrix. = 'L': A is a lower triangular matrix. = 'U': A is an upper triangular matrix. = 'H': A is an upper Hessenberg matrix. = 'B': A is a symmetric band matrix with lower bandwidth KL and upper bandwidth KU and with the only the lower half stored. = 'Q': A is a symmetric band matrix with lower bandwidth KL and upper bandwidth KU and with the only the upper half stored. = 'Z': A is a band matrix with lower bandwidth KL and upper bandwidth KU. KL (input) INTEGER The lower bandwidth of A. Referenced only if TYPE = 'B', 'Q' or 'Z'. KU (input) INTEGER The upper bandwidth of A. Referenced only if TYPE = 'B', 'Q' or 'Z'. CFROM (input) DOUBLE PRECISION CTO (input) DOUBLE PRECISION The matrix A is multiplied by CTO/CFROM. A(I,J) is computed without over/underflow if the final result CTO*A(I,J)/CFROM can be represented without over/underflow. CFROM must be nonzero. M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) The matrix to be multiplied by CTO/CFROM. See TYPE for the storage type. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). INFO (output) INTEGER 0 - successful exit <0 - if INFO = -i, the i-th argument had an illegal value. ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; if (lsame_(type__, "G")) { itype = 0; } else if (lsame_(type__, "L")) { itype = 1; } else if (lsame_(type__, "U")) { itype = 2; } else if (lsame_(type__, "H")) { itype = 3; } else if (lsame_(type__, "B")) { itype = 4; } else if (lsame_(type__, "Q")) { itype = 5; } else if (lsame_(type__, "Z")) { itype = 6; } else { itype = -1; } if (itype == -1) { *info = -1; } else if (*cfrom == 0. || disnan_(cfrom)) { *info = -4; } else if (disnan_(cto)) { *info = -5; } else if (*m < 0) { *info = -6; } else if (*n < 0 || itype == 4 && *n != *m || itype == 5 && *n != *m) { *info = -7; } else if (itype <= 3 && *lda < max(1,*m)) { *info = -9; } else if (itype >= 4) { /* Computing MAX */ i__1 = *m - 1; if (*kl < 0 || *kl > max(i__1,0)) { *info = -2; } else /* if(complicated condition) */ { /* Computing MAX */ i__1 = *n - 1; if (*ku < 0 || *ku > max(i__1,0) || (itype == 4 || itype == 5) && *kl != *ku) { *info = -3; } else if (itype == 4 && *lda < *kl + 1 || itype == 5 && *lda < * ku + 1 || itype == 6 && *lda < (*kl << 1) + *ku + 1) { *info = -9; } } } if (*info != 0) { i__1 = -(*info); xerbla_("ZLASCL", &i__1); return 0; } /* Quick return if possible */ if (*n == 0 || *m == 0) { return 0; } /* Get machine parameters */ smlnum = SAFEMINIMUM; bignum = 1. / smlnum; cfromc = *cfrom; ctoc = *cto; L10: cfrom1 = cfromc * smlnum; if (cfrom1 == cfromc) { /* CFROMC is an inf. Multiply by a correctly signed zero for finite CTOC, or a NaN if CTOC is infinite. */ mul = ctoc / cfromc; done = TRUE_; cto1 = ctoc; } else { cto1 = ctoc / bignum; if (cto1 == ctoc) { /* CTOC is either 0 or an inf. In both cases, CTOC itself serves as the correct multiplication factor. */ mul = ctoc; done = TRUE_; cfromc = 1.; } else if (abs(cfrom1) > abs(ctoc) && ctoc != 0.) { mul = smlnum; done = FALSE_; cfromc = cfrom1; } else if (abs(cto1) > abs(cfromc)) { mul = bignum; done = FALSE_; ctoc = cto1; } else { mul = ctoc / cfromc; done = TRUE_; } } if (itype == 0) { /* Full matrix */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L20: */ } /* L30: */ } } else if (itype == 1) { /* Lower triangular matrix */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = j; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L40: */ } /* L50: */ } } else if (itype == 2) { /* Upper triangular matrix */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = min(j,*m); for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L60: */ } /* L70: */ } } else if (itype == 3) { /* Upper Hessenberg matrix */ i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MIN */ i__3 = j + 1; i__2 = min(i__3,*m); for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L80: */ } /* L90: */ } } else if (itype == 4) { /* Lower half of a symmetric band matrix */ k3 = *kl + 1; k4 = *n + 1; i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MIN */ i__3 = k3, i__4 = k4 - j; i__2 = min(i__3,i__4); for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L100: */ } /* L110: */ } } else if (itype == 5) { /* Upper half of a symmetric band matrix */ k1 = *ku + 2; k3 = *ku + 1; i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__2 = k1 - j; i__3 = k3; for (i__ = max(i__2,1); i__ <= i__3; ++i__) { i__2 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L120: */ } /* L130: */ } } else if (itype == 6) { /* Band matrix */ k1 = *kl + *ku + 2; k2 = *kl + 1; k3 = (*kl << 1) + *ku + 1; k4 = *kl + *ku + 1 + *m; i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__3 = k1 - j; /* Computing MIN */ i__4 = k3, i__5 = k4 - j; i__2 = min(i__4,i__5); for (i__ = max(i__3,k2); i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + j * a_dim1; z__1.r = mul * a[i__4].r, z__1.i = mul * a[i__4].i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L140: */ } /* L150: */ } } if (! done) { goto L10; } return 0; /* End of ZLASCL */ } /* zlascl_ */ /* Subroutine */ int zlaset_(char *uplo, integer *m, integer *n, doublecomplex *alpha, doublecomplex *beta, doublecomplex *a, integer * lda) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; /* Local variables */ static integer i__, j; extern logical lsame_(char *, char *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLASET initializes a 2-D array A to BETA on the diagonal and ALPHA on the offdiagonals. Arguments ========= UPLO (input) CHARACTER*1 Specifies the part of the matrix A to be set. = 'U': Upper triangular part is set. The lower triangle is unchanged. = 'L': Lower triangular part is set. The upper triangle is unchanged. Otherwise: All of the matrix A is set. M (input) INTEGER On entry, M specifies the number of rows of A. N (input) INTEGER On entry, N specifies the number of columns of A. ALPHA (input) COMPLEX*16 All the offdiagonal array elements are set to ALPHA. BETA (input) COMPLEX*16 All the diagonal array elements are set to BETA. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the m by n matrix A. On exit, A(i,j) = ALPHA, 1 <= i <= m, 1 <= j <= n, i.ne.j; A(i,i) = BETA , 1 <= i <= min(m,n) LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). ===================================================================== */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ if (lsame_(uplo, "U")) { /* Set the diagonal to BETA and the strictly upper triangular part of the array to ALPHA. */ i__1 = *n; for (j = 2; j <= i__1; ++j) { /* Computing MIN */ i__3 = j - 1; i__2 = min(i__3,*m); for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = alpha->r, a[i__3].i = alpha->i; /* L10: */ } /* L20: */ } i__1 = min(*n,*m); for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * a_dim1; a[i__2].r = beta->r, a[i__2].i = beta->i; /* L30: */ } } else if (lsame_(uplo, "L")) { /* Set the diagonal to BETA and the strictly lower triangular part of the array to ALPHA. */ i__1 = min(*m,*n); for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = j + 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = alpha->r, a[i__3].i = alpha->i; /* L40: */ } /* L50: */ } i__1 = min(*n,*m); for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * a_dim1; a[i__2].r = beta->r, a[i__2].i = beta->i; /* L60: */ } } else { /* Set the array to BETA on the diagonal and ALPHA on the offdiagonal. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = alpha->r, a[i__3].i = alpha->i; /* L70: */ } /* L80: */ } i__1 = min(*m,*n); for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * a_dim1; a[i__2].r = beta->r, a[i__2].i = beta->i; /* L90: */ } } return 0; /* End of ZLASET */ } /* zlaset_ */ /* Subroutine */ int zlasr_(char *side, char *pivot, char *direct, integer *m, integer *n, doublereal *c__, doublereal *s, doublecomplex *a, integer *lda) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; doublecomplex z__1, z__2, z__3; /* Local variables */ static integer i__, j, info; static doublecomplex temp; extern logical lsame_(char *, char *); static doublereal ctemp, stemp; extern /* Subroutine */ int xerbla_(char *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLASR applies a sequence of real plane rotations to a complex matrix A, from either the left or the right. When SIDE = 'L', the transformation takes the form A := P*A and when SIDE = 'R', the transformation takes the form A := A*P**T where P is an orthogonal matrix consisting of a sequence of z plane rotations, with z = M when SIDE = 'L' and z = N when SIDE = 'R', and P**T is the transpose of P. When DIRECT = 'F' (Forward sequence), then P = P(z-1) * ... * P(2) * P(1) and when DIRECT = 'B' (Backward sequence), then P = P(1) * P(2) * ... * P(z-1) where P(k) is a plane rotation matrix defined by the 2-by-2 rotation R(k) = ( c(k) s(k) ) = ( -s(k) c(k) ). When PIVOT = 'V' (Variable pivot), the rotation is performed for the plane (k,k+1), i.e., P(k) has the form P(k) = ( 1 ) ( ... ) ( 1 ) ( c(k) s(k) ) ( -s(k) c(k) ) ( 1 ) ( ... ) ( 1 ) where R(k) appears as a rank-2 modification to the identity matrix in rows and columns k and k+1. When PIVOT = 'T' (Top pivot), the rotation is performed for the plane (1,k+1), so P(k) has the form P(k) = ( c(k) s(k) ) ( 1 ) ( ... ) ( 1 ) ( -s(k) c(k) ) ( 1 ) ( ... ) ( 1 ) where R(k) appears in rows and columns 1 and k+1. Similarly, when PIVOT = 'B' (Bottom pivot), the rotation is performed for the plane (k,z), giving P(k) the form P(k) = ( 1 ) ( ... ) ( 1 ) ( c(k) s(k) ) ( 1 ) ( ... ) ( 1 ) ( -s(k) c(k) ) where R(k) appears in rows and columns k and z. The rotations are performed without ever forming P(k) explicitly. Arguments ========= SIDE (input) CHARACTER*1 Specifies whether the plane rotation matrix P is applied to A on the left or the right. = 'L': Left, compute A := P*A = 'R': Right, compute A:= A*P**T PIVOT (input) CHARACTER*1 Specifies the plane for which P(k) is a plane rotation matrix. = 'V': Variable pivot, the plane (k,k+1) = 'T': Top pivot, the plane (1,k+1) = 'B': Bottom pivot, the plane (k,z) DIRECT (input) CHARACTER*1 Specifies whether P is a forward or backward sequence of plane rotations. = 'F': Forward, P = P(z-1)*...*P(2)*P(1) = 'B': Backward, P = P(1)*P(2)*...*P(z-1) M (input) INTEGER The number of rows of the matrix A. If m <= 1, an immediate return is effected. N (input) INTEGER The number of columns of the matrix A. If n <= 1, an immediate return is effected. C (input) DOUBLE PRECISION array, dimension (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' The cosines c(k) of the plane rotations. S (input) DOUBLE PRECISION array, dimension (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' The sines s(k) of the plane rotations. The 2-by-2 plane rotation part of the matrix P(k), R(k), has the form R(k) = ( c(k) s(k) ) ( -s(k) c(k) ). A (input/output) COMPLEX*16 array, dimension (LDA,N) The M-by-N matrix A. On exit, A is overwritten by P*A if SIDE = 'R' or by A*P**T if SIDE = 'L'. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M). ===================================================================== Test the input parameters */ /* Parameter adjustments */ --c__; --s; a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ info = 0; if (! (lsame_(side, "L") || lsame_(side, "R"))) { info = 1; } else if (! (lsame_(pivot, "V") || lsame_(pivot, "T") || lsame_(pivot, "B"))) { info = 2; } else if (! (lsame_(direct, "F") || lsame_(direct, "B"))) { info = 3; } else if (*m < 0) { info = 4; } else if (*n < 0) { info = 5; } else if (*lda < max(1,*m)) { info = 9; } if (info != 0) { xerbla_("ZLASR ", &info); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } if (lsame_(side, "L")) { /* Form P * A */ if (lsame_(pivot, "V")) { if (lsame_(direct, "F")) { i__1 = *m - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = j + 1 + i__ * a_dim1; temp.r = a[i__3].r, temp.i = a[i__3].i; i__3 = j + 1 + i__ * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__4 = j + i__ * a_dim1; z__3.r = stemp * a[i__4].r, z__3.i = stemp * a[ i__4].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; i__3 = j + i__ * a_dim1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__4 = j + i__ * a_dim1; z__3.r = ctemp * a[i__4].r, z__3.i = ctemp * a[ i__4].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L10: */ } } /* L20: */ } } else if (lsame_(direct, "B")) { for (j = *m - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = j + 1 + i__ * a_dim1; temp.r = a[i__2].r, temp.i = a[i__2].i; i__2 = j + 1 + i__ * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__3 = j + i__ * a_dim1; z__3.r = stemp * a[i__3].r, z__3.i = stemp * a[ i__3].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = j + i__ * a_dim1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__3 = j + i__ * a_dim1; z__3.r = ctemp * a[i__3].r, z__3.i = ctemp * a[ i__3].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L30: */ } } /* L40: */ } } } else if (lsame_(pivot, "T")) { if (lsame_(direct, "F")) { i__1 = *m; for (j = 2; j <= i__1; ++j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1. || stemp != 0.) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = j + i__ * a_dim1; temp.r = a[i__3].r, temp.i = a[i__3].i; i__3 = j + i__ * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__4 = i__ * a_dim1 + 1; z__3.r = stemp * a[i__4].r, z__3.i = stemp * a[ i__4].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; i__3 = i__ * a_dim1 + 1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__4 = i__ * a_dim1 + 1; z__3.r = ctemp * a[i__4].r, z__3.i = ctemp * a[ i__4].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L50: */ } } /* L60: */ } } else if (lsame_(direct, "B")) { for (j = *m; j >= 2; --j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1. || stemp != 0.) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = j + i__ * a_dim1; temp.r = a[i__2].r, temp.i = a[i__2].i; i__2 = j + i__ * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__3 = i__ * a_dim1 + 1; z__3.r = stemp * a[i__3].r, z__3.i = stemp * a[ i__3].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = i__ * a_dim1 + 1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__3 = i__ * a_dim1 + 1; z__3.r = ctemp * a[i__3].r, z__3.i = ctemp * a[ i__3].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L70: */ } } /* L80: */ } } } else if (lsame_(pivot, "B")) { if (lsame_(direct, "F")) { i__1 = *m - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = j + i__ * a_dim1; temp.r = a[i__3].r, temp.i = a[i__3].i; i__3 = j + i__ * a_dim1; i__4 = *m + i__ * a_dim1; z__2.r = stemp * a[i__4].r, z__2.i = stemp * a[ i__4].i; z__3.r = ctemp * temp.r, z__3.i = ctemp * temp.i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; i__3 = *m + i__ * a_dim1; i__4 = *m + i__ * a_dim1; z__2.r = ctemp * a[i__4].r, z__2.i = ctemp * a[ i__4].i; z__3.r = stemp * temp.r, z__3.i = stemp * temp.i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L90: */ } } /* L100: */ } } else if (lsame_(direct, "B")) { for (j = *m - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = j + i__ * a_dim1; temp.r = a[i__2].r, temp.i = a[i__2].i; i__2 = j + i__ * a_dim1; i__3 = *m + i__ * a_dim1; z__2.r = stemp * a[i__3].r, z__2.i = stemp * a[ i__3].i; z__3.r = ctemp * temp.r, z__3.i = ctemp * temp.i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = *m + i__ * a_dim1; i__3 = *m + i__ * a_dim1; z__2.r = ctemp * a[i__3].r, z__2.i = ctemp * a[ i__3].i; z__3.r = stemp * temp.r, z__3.i = stemp * temp.i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L110: */ } } /* L120: */ } } } } else if (lsame_(side, "R")) { /* Form A * P' */ if (lsame_(pivot, "V")) { if (lsame_(direct, "F")) { i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + (j + 1) * a_dim1; temp.r = a[i__3].r, temp.i = a[i__3].i; i__3 = i__ + (j + 1) * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__4 = i__ + j * a_dim1; z__3.r = stemp * a[i__4].r, z__3.i = stemp * a[ i__4].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; i__3 = i__ + j * a_dim1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__4 = i__ + j * a_dim1; z__3.r = ctemp * a[i__4].r, z__3.i = ctemp * a[ i__4].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L130: */ } } /* L140: */ } } else if (lsame_(direct, "B")) { for (j = *n - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + (j + 1) * a_dim1; temp.r = a[i__2].r, temp.i = a[i__2].i; i__2 = i__ + (j + 1) * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__3 = i__ + j * a_dim1; z__3.r = stemp * a[i__3].r, z__3.i = stemp * a[ i__3].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = i__ + j * a_dim1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__3 = i__ + j * a_dim1; z__3.r = ctemp * a[i__3].r, z__3.i = ctemp * a[ i__3].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L150: */ } } /* L160: */ } } } else if (lsame_(pivot, "T")) { if (lsame_(direct, "F")) { i__1 = *n; for (j = 2; j <= i__1; ++j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1. || stemp != 0.) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; temp.r = a[i__3].r, temp.i = a[i__3].i; i__3 = i__ + j * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__4 = i__ + a_dim1; z__3.r = stemp * a[i__4].r, z__3.i = stemp * a[ i__4].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; i__3 = i__ + a_dim1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__4 = i__ + a_dim1; z__3.r = ctemp * a[i__4].r, z__3.i = ctemp * a[ i__4].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L170: */ } } /* L180: */ } } else if (lsame_(direct, "B")) { for (j = *n; j >= 2; --j) { ctemp = c__[j - 1]; stemp = s[j - 1]; if (ctemp != 1. || stemp != 0.) { i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + j * a_dim1; temp.r = a[i__2].r, temp.i = a[i__2].i; i__2 = i__ + j * a_dim1; z__2.r = ctemp * temp.r, z__2.i = ctemp * temp.i; i__3 = i__ + a_dim1; z__3.r = stemp * a[i__3].r, z__3.i = stemp * a[ i__3].i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = i__ + a_dim1; z__2.r = stemp * temp.r, z__2.i = stemp * temp.i; i__3 = i__ + a_dim1; z__3.r = ctemp * a[i__3].r, z__3.i = ctemp * a[ i__3].i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L190: */ } } /* L200: */ } } } else if (lsame_(pivot, "B")) { if (lsame_(direct, "F")) { i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__2 = *m; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; temp.r = a[i__3].r, temp.i = a[i__3].i; i__3 = i__ + j * a_dim1; i__4 = i__ + *n * a_dim1; z__2.r = stemp * a[i__4].r, z__2.i = stemp * a[ i__4].i; z__3.r = ctemp * temp.r, z__3.i = ctemp * temp.i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; i__3 = i__ + *n * a_dim1; i__4 = i__ + *n * a_dim1; z__2.r = ctemp * a[i__4].r, z__2.i = ctemp * a[ i__4].i; z__3.r = stemp * temp.r, z__3.i = stemp * temp.i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__3].r = z__1.r, a[i__3].i = z__1.i; /* L210: */ } } /* L220: */ } } else if (lsame_(direct, "B")) { for (j = *n - 1; j >= 1; --j) { ctemp = c__[j]; stemp = s[j]; if (ctemp != 1. || stemp != 0.) { i__1 = *m; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + j * a_dim1; temp.r = a[i__2].r, temp.i = a[i__2].i; i__2 = i__ + j * a_dim1; i__3 = i__ + *n * a_dim1; z__2.r = stemp * a[i__3].r, z__2.i = stemp * a[ i__3].i; z__3.r = ctemp * temp.r, z__3.i = ctemp * temp.i; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = i__ + *n * a_dim1; i__3 = i__ + *n * a_dim1; z__2.r = ctemp * a[i__3].r, z__2.i = ctemp * a[ i__3].i; z__3.r = stemp * temp.r, z__3.i = stemp * temp.i; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; a[i__2].r = z__1.r, a[i__2].i = z__1.i; /* L230: */ } } /* L240: */ } } } } return 0; /* End of ZLASR */ } /* zlasr_ */ /* Subroutine */ int zlassq_(integer *n, doublecomplex *x, integer *incx, doublereal *scale, doublereal *sumsq) { /* System generated locals */ integer i__1, i__2, i__3; doublereal d__1; /* Builtin functions */ double d_imag(doublecomplex *); /* Local variables */ static integer ix; static doublereal temp1; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLASSQ returns the values scl and ssq such that ( scl**2 )*ssq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, where x( i ) = abs( X( 1 + ( i - 1 )*INCX ) ). The value of sumsq is assumed to be at least unity and the value of ssq will then satisfy 1.0 .le. ssq .le. ( sumsq + 2*n ). scale is assumed to be non-negative and scl returns the value scl = max( scale, abs( real( x( i ) ) ), abs( aimag( x( i ) ) ) ), i scale and sumsq must be supplied in SCALE and SUMSQ respectively. SCALE and SUMSQ are overwritten by scl and ssq respectively. The routine makes only one pass through the vector X. Arguments ========= N (input) INTEGER The number of elements to be used from the vector X. X (input) COMPLEX*16 array, dimension (N) The vector x as described above. x( i ) = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n. INCX (input) INTEGER The increment between successive values of the vector X. INCX > 0. SCALE (input/output) DOUBLE PRECISION On entry, the value scale in the equation above. On exit, SCALE is overwritten with the value scl . SUMSQ (input/output) DOUBLE PRECISION On entry, the value sumsq in the equation above. On exit, SUMSQ is overwritten with the value ssq . ===================================================================== */ /* Parameter adjustments */ --x; /* Function Body */ if (*n > 0) { i__1 = (*n - 1) * *incx + 1; i__2 = *incx; for (ix = 1; i__2 < 0 ? ix >= i__1 : ix <= i__1; ix += i__2) { i__3 = ix; if (x[i__3].r != 0.) { i__3 = ix; temp1 = (d__1 = x[i__3].r, abs(d__1)); if (*scale < temp1) { /* Computing 2nd power */ d__1 = *scale / temp1; *sumsq = *sumsq * (d__1 * d__1) + 1; *scale = temp1; } else { /* Computing 2nd power */ d__1 = temp1 / *scale; *sumsq += d__1 * d__1; } } if (d_imag(&x[ix]) != 0.) { temp1 = (d__1 = d_imag(&x[ix]), abs(d__1)); if (*scale < temp1) { /* Computing 2nd power */ d__1 = *scale / temp1; *sumsq = *sumsq * (d__1 * d__1) + 1; *scale = temp1; } else { /* Computing 2nd power */ d__1 = temp1 / *scale; *sumsq += d__1 * d__1; } } /* L10: */ } } return 0; /* End of ZLASSQ */ } /* zlassq_ */ /* Subroutine */ int zlaswp_(integer *n, doublecomplex *a, integer *lda, integer *k1, integer *k2, integer *ipiv, integer *incx) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6; /* Local variables */ static integer i__, j, k, i1, i2, n32, ip, ix, ix0, inc; static doublecomplex temp; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLASWP performs a series of row interchanges on the matrix A. One row interchange is initiated for each of rows K1 through K2 of A. Arguments ========= N (input) INTEGER The number of columns of the matrix A. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the matrix of column dimension N to which the row interchanges will be applied. On exit, the permuted matrix. LDA (input) INTEGER The leading dimension of the array A. K1 (input) INTEGER The first element of IPIV for which a row interchange will be done. K2 (input) INTEGER The last element of IPIV for which a row interchange will be done. IPIV (input) INTEGER array, dimension (K2*abs(INCX)) The vector of pivot indices. Only the elements in positions K1 through K2 of IPIV are accessed. IPIV(K) = L implies rows K and L are to be interchanged. INCX (input) INTEGER The increment between successive values of IPIV. If IPIV is negative, the pivots are applied in reverse order. Further Details =============== Modified by R. C. Whaley, Computer Science Dept., Univ. of Tenn., Knoxville, USA ===================================================================== Interchange row I with row IPIV(I) for each of rows K1 through K2. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --ipiv; /* Function Body */ if (*incx > 0) { ix0 = *k1; i1 = *k1; i2 = *k2; inc = 1; } else if (*incx < 0) { ix0 = (1 - *k2) * *incx + 1; i1 = *k2; i2 = *k1; inc = -1; } else { return 0; } n32 = *n / 32 << 5; if (n32 != 0) { i__1 = n32; for (j = 1; j <= i__1; j += 32) { ix = ix0; i__2 = i2; i__3 = inc; for (i__ = i1; i__3 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__3) { ip = ipiv[ix]; if (ip != i__) { i__4 = j + 31; for (k = j; k <= i__4; ++k) { i__5 = i__ + k * a_dim1; temp.r = a[i__5].r, temp.i = a[i__5].i; i__5 = i__ + k * a_dim1; i__6 = ip + k * a_dim1; a[i__5].r = a[i__6].r, a[i__5].i = a[i__6].i; i__5 = ip + k * a_dim1; a[i__5].r = temp.r, a[i__5].i = temp.i; /* L10: */ } } ix += *incx; /* L20: */ } /* L30: */ } } if (n32 != *n) { ++n32; ix = ix0; i__1 = i2; i__3 = inc; for (i__ = i1; i__3 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__3) { ip = ipiv[ix]; if (ip != i__) { i__2 = *n; for (k = n32; k <= i__2; ++k) { i__4 = i__ + k * a_dim1; temp.r = a[i__4].r, temp.i = a[i__4].i; i__4 = i__ + k * a_dim1; i__5 = ip + k * a_dim1; a[i__4].r = a[i__5].r, a[i__4].i = a[i__5].i; i__4 = ip + k * a_dim1; a[i__4].r = temp.r, a[i__4].i = temp.i; /* L40: */ } } ix += *incx; /* L50: */ } } return 0; /* End of ZLASWP */ } /* zlaswp_ */ /* Subroutine */ int zlatrd_(char *uplo, integer *n, integer *nb, doublecomplex *a, integer *lda, doublereal *e, doublecomplex *tau, doublecomplex *w, integer *ldw) { /* System generated locals */ integer a_dim1, a_offset, w_dim1, w_offset, i__1, i__2, i__3; doublereal d__1; doublecomplex z__1, z__2, z__3, z__4; /* Local variables */ static integer i__, iw; static doublecomplex alpha; extern logical lsame_(char *, char *); extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *); extern /* Double Complex */ VOID zdotc_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zhemv_(char *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), zlacgv_(integer *, doublecomplex *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLATRD reduces NB rows and columns of a complex Hermitian matrix A to Hermitian tridiagonal form by a unitary similarity transformation Q' * A * Q, and returns the matrices V and W which are needed to apply the transformation to the unreduced part of A. If UPLO = 'U', ZLATRD reduces the last NB rows and columns of a matrix, of which the upper triangle is supplied; if UPLO = 'L', ZLATRD reduces the first NB rows and columns of a matrix, of which the lower triangle is supplied. This is an auxiliary routine called by ZHETRD. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the upper or lower triangular part of the Hermitian matrix A is stored: = 'U': Upper triangular = 'L': Lower triangular N (input) INTEGER The order of the matrix A. NB (input) INTEGER The number of rows and columns to be reduced. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading n-by-n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n-by-n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit: if UPLO = 'U', the last NB columns have been reduced to tridiagonal form, with the diagonal elements overwriting the diagonal elements of A; the elements above the diagonal with the array TAU, represent the unitary matrix Q as a product of elementary reflectors; if UPLO = 'L', the first NB columns have been reduced to tridiagonal form, with the diagonal elements overwriting the diagonal elements of A; the elements below the diagonal with the array TAU, represent the unitary matrix Q as a product of elementary reflectors. See Further Details. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). E (output) DOUBLE PRECISION array, dimension (N-1) If UPLO = 'U', E(n-nb:n-1) contains the superdiagonal elements of the last NB columns of the reduced matrix; if UPLO = 'L', E(1:nb) contains the subdiagonal elements of the first NB columns of the reduced matrix. TAU (output) COMPLEX*16 array, dimension (N-1) The scalar factors of the elementary reflectors, stored in TAU(n-nb:n-1) if UPLO = 'U', and in TAU(1:nb) if UPLO = 'L'. See Further Details. W (output) COMPLEX*16 array, dimension (LDW,NB) The n-by-nb matrix W required to update the unreduced part of A. LDW (input) INTEGER The leading dimension of the array W. LDW >= max(1,N). Further Details =============== If UPLO = 'U', the matrix Q is represented as a product of elementary reflectors Q = H(n) H(n-1) . . . H(n-nb+1). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(i:n) = 0 and v(i-1) = 1; v(1:i-1) is stored on exit in A(1:i-1,i), and tau in TAU(i-1). If UPLO = 'L', the matrix Q is represented as a product of elementary reflectors Q = H(1) H(2) . . . H(nb). Each H(i) has the form H(i) = I - tau * v * v' where tau is a complex scalar, and v is a complex vector with v(1:i) = 0 and v(i+1) = 1; v(i+1:n) is stored on exit in A(i+1:n,i), and tau in TAU(i). The elements of the vectors v together form the n-by-nb matrix V which is needed, with W, to apply the transformation to the unreduced part of the matrix, using a Hermitian rank-2k update of the form: A := A - V*W' - W*V'. The contents of A on exit are illustrated by the following examples with n = 5 and nb = 2: if UPLO = 'U': if UPLO = 'L': ( a a a v4 v5 ) ( d ) ( a a v4 v5 ) ( 1 d ) ( a 1 v5 ) ( v1 1 a ) ( d 1 ) ( v1 v2 a a ) ( d ) ( v1 v2 a a a ) where d denotes a diagonal element of the reduced matrix, a denotes an element of the original matrix that is unchanged, and vi denotes an element of the vector defining H(i). ===================================================================== Quick return if possible */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --e; --tau; w_dim1 = *ldw; w_offset = 1 + w_dim1; w -= w_offset; /* Function Body */ if (*n <= 0) { return 0; } if (lsame_(uplo, "U")) { /* Reduce last NB columns of upper triangle */ i__1 = *n - *nb + 1; for (i__ = *n; i__ >= i__1; --i__) { iw = i__ - *n + *nb; if (i__ < *n) { /* Update A(1:i,i) */ i__2 = i__ + i__ * a_dim1; i__3 = i__ + i__ * a_dim1; d__1 = a[i__3].r; a[i__2].r = d__1, a[i__2].i = 0.; i__2 = *n - i__; zlacgv_(&i__2, &w[i__ + (iw + 1) * w_dim1], ldw); i__2 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__, &i__2, &z__1, &a[(i__ + 1) * a_dim1 + 1], lda, &w[i__ + (iw + 1) * w_dim1], ldw, & c_b57, &a[i__ * a_dim1 + 1], &c__1); i__2 = *n - i__; zlacgv_(&i__2, &w[i__ + (iw + 1) * w_dim1], ldw); i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); i__2 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__, &i__2, &z__1, &w[(iw + 1) * w_dim1 + 1], ldw, &a[i__ + (i__ + 1) * a_dim1], lda, & c_b57, &a[i__ * a_dim1 + 1], &c__1); i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); i__2 = i__ + i__ * a_dim1; i__3 = i__ + i__ * a_dim1; d__1 = a[i__3].r; a[i__2].r = d__1, a[i__2].i = 0.; } if (i__ > 1) { /* Generate elementary reflector H(i) to annihilate A(1:i-2,i) */ i__2 = i__ - 1 + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = i__ - 1; zlarfg_(&i__2, &alpha, &a[i__ * a_dim1 + 1], &c__1, &tau[i__ - 1]); i__2 = i__ - 1; e[i__2] = alpha.r; i__2 = i__ - 1 + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute W(1:i-1,i) */ i__2 = i__ - 1; zhemv_("Upper", &i__2, &c_b57, &a[a_offset], lda, &a[i__ * a_dim1 + 1], &c__1, &c_b56, &w[iw * w_dim1 + 1], & c__1); if (i__ < *n) { i__2 = i__ - 1; i__3 = *n - i__; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &w[( iw + 1) * w_dim1 + 1], ldw, &a[i__ * a_dim1 + 1], &c__1, &c_b56, &w[i__ + 1 + iw * w_dim1], &c__1); i__2 = i__ - 1; i__3 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[(i__ + 1) * a_dim1 + 1], lda, &w[i__ + 1 + iw * w_dim1], & c__1, &c_b57, &w[iw * w_dim1 + 1], &c__1); i__2 = i__ - 1; i__3 = *n - i__; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[( i__ + 1) * a_dim1 + 1], lda, &a[i__ * a_dim1 + 1], &c__1, &c_b56, &w[i__ + 1 + iw * w_dim1], &c__1); i__2 = i__ - 1; i__3 = *n - i__; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &w[(iw + 1) * w_dim1 + 1], ldw, &w[i__ + 1 + iw * w_dim1], & c__1, &c_b57, &w[iw * w_dim1 + 1], &c__1); } i__2 = i__ - 1; zscal_(&i__2, &tau[i__ - 1], &w[iw * w_dim1 + 1], &c__1); z__3.r = -.5, z__3.i = -0.; i__2 = i__ - 1; z__2.r = z__3.r * tau[i__2].r - z__3.i * tau[i__2].i, z__2.i = z__3.r * tau[i__2].i + z__3.i * tau[i__2].r; i__3 = i__ - 1; zdotc_(&z__4, &i__3, &w[iw * w_dim1 + 1], &c__1, &a[i__ * a_dim1 + 1], &c__1); z__1.r = z__2.r * z__4.r - z__2.i * z__4.i, z__1.i = z__2.r * z__4.i + z__2.i * z__4.r; alpha.r = z__1.r, alpha.i = z__1.i; i__2 = i__ - 1; zaxpy_(&i__2, &alpha, &a[i__ * a_dim1 + 1], &c__1, &w[iw * w_dim1 + 1], &c__1); } /* L10: */ } } else { /* Reduce first NB columns of lower triangle */ i__1 = *nb; for (i__ = 1; i__ <= i__1; ++i__) { /* Update A(i:n,i) */ i__2 = i__ + i__ * a_dim1; i__3 = i__ + i__ * a_dim1; d__1 = a[i__3].r; a[i__2].r = d__1, a[i__2].i = 0.; i__2 = i__ - 1; zlacgv_(&i__2, &w[i__ + w_dim1], ldw); i__2 = *n - i__ + 1; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[i__ + a_dim1], lda, &w[i__ + w_dim1], ldw, &c_b57, &a[i__ + i__ * a_dim1], & c__1); i__2 = i__ - 1; zlacgv_(&i__2, &w[i__ + w_dim1], ldw); i__2 = i__ - 1; zlacgv_(&i__2, &a[i__ + a_dim1], lda); i__2 = *n - i__ + 1; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &w[i__ + w_dim1], ldw, &a[i__ + a_dim1], lda, &c_b57, &a[i__ + i__ * a_dim1], & c__1); i__2 = i__ - 1; zlacgv_(&i__2, &a[i__ + a_dim1], lda); i__2 = i__ + i__ * a_dim1; i__3 = i__ + i__ * a_dim1; d__1 = a[i__3].r; a[i__2].r = d__1, a[i__2].i = 0.; if (i__ < *n) { /* Generate elementary reflector H(i) to annihilate A(i+2:n,i) */ i__2 = i__ + 1 + i__ * a_dim1; alpha.r = a[i__2].r, alpha.i = a[i__2].i; i__2 = *n - i__; /* Computing MIN */ i__3 = i__ + 2; zlarfg_(&i__2, &alpha, &a[min(i__3,*n) + i__ * a_dim1], &c__1, &tau[i__]); i__2 = i__; e[i__2] = alpha.r; i__2 = i__ + 1 + i__ * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* Compute W(i+1:n,i) */ i__2 = *n - i__; zhemv_("Lower", &i__2, &c_b57, &a[i__ + 1 + (i__ + 1) * a_dim1], lda, &a[i__ + 1 + i__ * a_dim1], &c__1, & c_b56, &w[i__ + 1 + i__ * w_dim1], &c__1); i__2 = *n - i__; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &w[i__ + 1 + w_dim1], ldw, &a[i__ + 1 + i__ * a_dim1], &c__1, & c_b56, &w[i__ * w_dim1 + 1], &c__1); i__2 = *n - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[i__ + 1 + a_dim1], lda, &w[i__ * w_dim1 + 1], &c__1, &c_b57, &w[ i__ + 1 + i__ * w_dim1], &c__1); i__2 = *n - i__; i__3 = i__ - 1; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[i__ + 1 + a_dim1], lda, &a[i__ + 1 + i__ * a_dim1], &c__1, & c_b56, &w[i__ * w_dim1 + 1], &c__1); i__2 = *n - i__; i__3 = i__ - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &w[i__ + 1 + w_dim1], ldw, &w[i__ * w_dim1 + 1], &c__1, &c_b57, &w[ i__ + 1 + i__ * w_dim1], &c__1); i__2 = *n - i__; zscal_(&i__2, &tau[i__], &w[i__ + 1 + i__ * w_dim1], &c__1); z__3.r = -.5, z__3.i = -0.; i__2 = i__; z__2.r = z__3.r * tau[i__2].r - z__3.i * tau[i__2].i, z__2.i = z__3.r * tau[i__2].i + z__3.i * tau[i__2].r; i__3 = *n - i__; zdotc_(&z__4, &i__3, &w[i__ + 1 + i__ * w_dim1], &c__1, &a[ i__ + 1 + i__ * a_dim1], &c__1); z__1.r = z__2.r * z__4.r - z__2.i * z__4.i, z__1.i = z__2.r * z__4.i + z__2.i * z__4.r; alpha.r = z__1.r, alpha.i = z__1.i; i__2 = *n - i__; zaxpy_(&i__2, &alpha, &a[i__ + 1 + i__ * a_dim1], &c__1, &w[ i__ + 1 + i__ * w_dim1], &c__1); } /* L20: */ } } return 0; /* End of ZLATRD */ } /* zlatrd_ */ /* Subroutine */ int zlatrs_(char *uplo, char *trans, char *diag, char * normin, integer *n, doublecomplex *a, integer *lda, doublecomplex *x, doublereal *scale, doublereal *cnorm, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1, d__2, d__3, d__4; doublecomplex z__1, z__2, z__3, z__4; /* Builtin functions */ double d_imag(doublecomplex *); void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j; static doublereal xj, rec, tjj; static integer jinc; static doublereal xbnd; static integer imax; static doublereal tmax; static doublecomplex tjjs; static doublereal xmax, grow; extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, integer *); extern logical lsame_(char *, char *); static doublereal tscal; static doublecomplex uscal; static integer jlast; static doublecomplex csumj; extern /* Double Complex */ VOID zdotc_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static logical upper; extern /* Double Complex */ VOID zdotu_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), ztrsv_( char *, char *, char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), dlabad_( doublereal *, doublereal *); extern integer idamax_(integer *, doublereal *, integer *); extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_( integer *, doublereal *, doublecomplex *, integer *); static doublereal bignum; extern integer izamax_(integer *, doublecomplex *, integer *); extern /* Double Complex */ VOID zladiv_(doublecomplex *, doublecomplex *, doublecomplex *); static logical notran; static integer jfirst; extern doublereal dzasum_(integer *, doublecomplex *, integer *); static doublereal smlnum; static logical nounit; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLATRS solves one of the triangular systems A * x = s*b, A**T * x = s*b, or A**H * x = s*b, with scaling to prevent overflow. Here A is an upper or lower triangular matrix, A**T denotes the transpose of A, A**H denotes the conjugate transpose of A, x and b are n-element vectors, and s is a scaling factor, usually less than or equal to 1, chosen so that the components of x will be less than the overflow threshold. If the unscaled problem will not cause overflow, the Level 2 BLAS routine ZTRSV is called. If the matrix A is singular (A(j,j) = 0 for some j), then s is set to 0 and a non-trivial solution to A*x = 0 is returned. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular TRANS (input) CHARACTER*1 Specifies the operation applied to A. = 'N': Solve A * x = s*b (No transpose) = 'T': Solve A**T * x = s*b (Transpose) = 'C': Solve A**H * x = s*b (Conjugate transpose) DIAG (input) CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular NORMIN (input) CHARACTER*1 Specifies whether CNORM has been set or not. = 'Y': CNORM contains the column norms on entry = 'N': CNORM is not set on entry. On exit, the norms will be computed and stored in CNORM. N (input) INTEGER The order of the matrix A. N >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) The triangular matrix A. If UPLO = 'U', the leading n by n upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. LDA (input) INTEGER The leading dimension of the array A. LDA >= max (1,N). X (input/output) COMPLEX*16 array, dimension (N) On entry, the right hand side b of the triangular system. On exit, X is overwritten by the solution vector x. SCALE (output) DOUBLE PRECISION The scaling factor s for the triangular system A * x = s*b, A**T * x = s*b, or A**H * x = s*b. If SCALE = 0, the matrix A is singular or badly scaled, and the vector x is an exact or approximate solution to A*x = 0. CNORM (input or output) DOUBLE PRECISION array, dimension (N) If NORMIN = 'Y', CNORM is an input argument and CNORM(j) contains the norm of the off-diagonal part of the j-th column of A. If TRANS = 'N', CNORM(j) must be greater than or equal to the infinity-norm, and if TRANS = 'T' or 'C', CNORM(j) must be greater than or equal to the 1-norm. If NORMIN = 'N', CNORM is an output argument and CNORM(j) returns the 1-norm of the offdiagonal part of the j-th column of A. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value Further Details ======= ======= A rough bound on x is computed; if that is less than overflow, ZTRSV is called, otherwise, specific code is used which checks for possible overflow or divide-by-zero at every operation. A columnwise scheme is used for solving A*x = b. The basic algorithm if A is lower triangular is x[1:n] := b[1:n] for j = 1, ..., n x(j) := x(j) / A(j,j) x[j+1:n] := x[j+1:n] - x(j) * A[j+1:n,j] end Define bounds on the components of x after j iterations of the loop: M(j) = bound on x[1:j] G(j) = bound on x[j+1:n] Initially, let M(0) = 0 and G(0) = max{x(i), i=1,...,n}. Then for iteration j+1 we have M(j+1) <= G(j) / | A(j+1,j+1) | G(j+1) <= G(j) + M(j+1) * | A[j+2:n,j+1] | <= G(j) ( 1 + CNORM(j+1) / | A(j+1,j+1) | ) where CNORM(j+1) is greater than or equal to the infinity-norm of column j+1 of A, not counting the diagonal. Hence G(j) <= G(0) product ( 1 + CNORM(i) / | A(i,i) | ) 1<=i<=j and |x(j)| <= ( G(0) / |A(j,j)| ) product ( 1 + CNORM(i) / |A(i,i)| ) 1<=i< j Since |x(j)| <= M(j), we use the Level 2 BLAS routine ZTRSV if the reciprocal of the largest M(j), j=1,..,n, is larger than max(underflow, 1/overflow). The bound on x(j) is also used to determine when a step in the columnwise method can be performed without fear of overflow. If the computed bound is greater than a large constant, x is scaled to prevent overflow, but if the bound overflows, x is set to 0, x(j) to 1, and scale to 0, and a non-trivial solution to A*x = 0 is found. Similarly, a row-wise scheme is used to solve A**T *x = b or A**H *x = b. The basic algorithm for A upper triangular is for j = 1, ..., n x(j) := ( b(j) - A[1:j-1,j]' * x[1:j-1] ) / A(j,j) end We simultaneously compute two bounds G(j) = bound on ( b(i) - A[1:i-1,i]' * x[1:i-1] ), 1<=i<=j M(j) = bound on x(i), 1<=i<=j The initial values are G(0) = 0, M(0) = max{b(i), i=1,..,n}, and we add the constraint G(j) >= G(j-1) and M(j) >= M(j-1) for j >= 1. Then the bound on x(j) is M(j) <= M(j-1) * ( 1 + CNORM(j) ) / | A(j,j) | <= M(0) * product ( ( 1 + CNORM(i) ) / |A(i,i)| ) 1<=i<=j and we can safely call ZTRSV if 1/M(n) and 1/G(n) are both greater than max(underflow, 1/overflow). ===================================================================== */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --x; --cnorm; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); notran = lsame_(trans, "N"); nounit = lsame_(diag, "N"); /* Test the input parameters. */ if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (! notran && ! lsame_(trans, "T") && ! lsame_(trans, "C")) { *info = -2; } else if (! nounit && ! lsame_(diag, "U")) { *info = -3; } else if (! lsame_(normin, "Y") && ! lsame_(normin, "N")) { *info = -4; } else if (*n < 0) { *info = -5; } else if (*lda < max(1,*n)) { *info = -7; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLATRS", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Determine machine dependent parameters to control overflow. */ smlnum = SAFEMINIMUM; bignum = 1. / smlnum; dlabad_(&smlnum, &bignum); smlnum /= PRECISION; bignum = 1. / smlnum; *scale = 1.; if (lsame_(normin, "N")) { /* Compute the 1-norm of each column, not including the diagonal. */ if (upper) { /* A is upper triangular. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = j - 1; cnorm[j] = dzasum_(&i__2, &a[j * a_dim1 + 1], &c__1); /* L10: */ } } else { /* A is lower triangular. */ i__1 = *n - 1; for (j = 1; j <= i__1; ++j) { i__2 = *n - j; cnorm[j] = dzasum_(&i__2, &a[j + 1 + j * a_dim1], &c__1); /* L20: */ } cnorm[*n] = 0.; } } /* Scale the column norms by TSCAL if the maximum element in CNORM is greater than BIGNUM/2. */ imax = idamax_(n, &cnorm[1], &c__1); tmax = cnorm[imax]; if (tmax <= bignum * .5) { tscal = 1.; } else { tscal = .5 / (smlnum * tmax); dscal_(n, &tscal, &cnorm[1], &c__1); } /* Compute a bound on the computed solution vector to see if the Level 2 BLAS routine ZTRSV can be used. */ xmax = 0.; i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__2 = j; d__3 = xmax, d__4 = (d__1 = x[i__2].r / 2., abs(d__1)) + (d__2 = d_imag(&x[j]) / 2., abs(d__2)); xmax = max(d__3,d__4); /* L30: */ } xbnd = xmax; if (notran) { /* Compute the growth in A * x = b. */ if (upper) { jfirst = *n; jlast = 1; jinc = -1; } else { jfirst = 1; jlast = *n; jinc = 1; } if (tscal != 1.) { grow = 0.; goto L60; } if (nounit) { /* A is non-unit triangular. Compute GROW = 1/G(j) and XBND = 1/M(j). Initially, G(0) = max{x(i), i=1,...,n}. */ grow = .5 / max(xbnd,smlnum); xbnd = grow; i__1 = jlast; i__2 = jinc; for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Exit the loop if the growth factor is too small. */ if (grow <= smlnum) { goto L60; } i__3 = j + j * a_dim1; tjjs.r = a[i__3].r, tjjs.i = a[i__3].i; tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs( d__2)); if (tjj >= smlnum) { /* M(j) = G(j-1) / abs(A(j,j)) Computing MIN */ d__1 = xbnd, d__2 = min(1.,tjj) * grow; xbnd = min(d__1,d__2); } else { /* M(j) could overflow, set XBND to 0. */ xbnd = 0.; } if (tjj + cnorm[j] >= smlnum) { /* G(j) = G(j-1)*( 1 + CNORM(j) / abs(A(j,j)) ) */ grow *= tjj / (tjj + cnorm[j]); } else { /* G(j) could overflow, set GROW to 0. */ grow = 0.; } /* L40: */ } grow = xbnd; } else { /* A is unit triangular. Compute GROW = 1/G(j), where G(0) = max{x(i), i=1,...,n}. Computing MIN */ d__1 = 1., d__2 = .5 / max(xbnd,smlnum); grow = min(d__1,d__2); i__2 = jlast; i__1 = jinc; for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) { /* Exit the loop if the growth factor is too small. */ if (grow <= smlnum) { goto L60; } /* G(j) = G(j-1)*( 1 + CNORM(j) ) */ grow *= 1. / (cnorm[j] + 1.); /* L50: */ } } L60: ; } else { /* Compute the growth in A**T * x = b or A**H * x = b. */ if (upper) { jfirst = 1; jlast = *n; jinc = 1; } else { jfirst = *n; jlast = 1; jinc = -1; } if (tscal != 1.) { grow = 0.; goto L90; } if (nounit) { /* A is non-unit triangular. Compute GROW = 1/G(j) and XBND = 1/M(j). Initially, M(0) = max{x(i), i=1,...,n}. */ grow = .5 / max(xbnd,smlnum); xbnd = grow; i__1 = jlast; i__2 = jinc; for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Exit the loop if the growth factor is too small. */ if (grow <= smlnum) { goto L90; } /* G(j) = max( G(j-1), M(j-1)*( 1 + CNORM(j) ) ) */ xj = cnorm[j] + 1.; /* Computing MIN */ d__1 = grow, d__2 = xbnd / xj; grow = min(d__1,d__2); i__3 = j + j * a_dim1; tjjs.r = a[i__3].r, tjjs.i = a[i__3].i; tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs( d__2)); if (tjj >= smlnum) { /* M(j) = M(j-1)*( 1 + CNORM(j) ) / abs(A(j,j)) */ if (xj > tjj) { xbnd *= tjj / xj; } } else { /* M(j) could overflow, set XBND to 0. */ xbnd = 0.; } /* L70: */ } grow = min(grow,xbnd); } else { /* A is unit triangular. Compute GROW = 1/G(j), where G(0) = max{x(i), i=1,...,n}. Computing MIN */ d__1 = 1., d__2 = .5 / max(xbnd,smlnum); grow = min(d__1,d__2); i__2 = jlast; i__1 = jinc; for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) { /* Exit the loop if the growth factor is too small. */ if (grow <= smlnum) { goto L90; } /* G(j) = ( 1 + CNORM(j) )*G(j-1) */ xj = cnorm[j] + 1.; grow /= xj; /* L80: */ } } L90: ; } if (grow * tscal > smlnum) { /* Use the Level 2 BLAS solve if the reciprocal of the bound on elements of X is not too small. */ ztrsv_(uplo, trans, diag, n, &a[a_offset], lda, &x[1], &c__1); } else { /* Use a Level 1 BLAS solve, scaling intermediate results. */ if (xmax > bignum * .5) { /* Scale X so that its components are less than or equal to BIGNUM in absolute value. */ *scale = bignum * .5 / xmax; zdscal_(n, scale, &x[1], &c__1); xmax = bignum; } else { xmax *= 2.; } if (notran) { /* Solve A * x = b */ i__1 = jlast; i__2 = jinc; for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Compute x(j) = b(j) / A(j,j), scaling x if necessary. */ i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); if (nounit) { i__3 = j + j * a_dim1; z__1.r = tscal * a[i__3].r, z__1.i = tscal * a[i__3].i; tjjs.r = z__1.r, tjjs.i = z__1.i; } else { tjjs.r = tscal, tjjs.i = 0.; if (tscal == 1.) { goto L110; } } tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs( d__2)); if (tjj > smlnum) { /* abs(A(j,j)) > SMLNUM: */ if (tjj < 1.) { if (xj > tjj * bignum) { /* Scale x by 1/b(j). */ rec = 1. / xj; zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } } i__3 = j; zladiv_(&z__1, &x[j], &tjjs); x[i__3].r = z__1.r, x[i__3].i = z__1.i; i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2)); } else if (tjj > 0.) { /* 0 < abs(A(j,j)) <= SMLNUM: */ if (xj > tjj * bignum) { /* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM to avoid overflow when dividing by A(j,j). */ rec = tjj * bignum / xj; if (cnorm[j] > 1.) { /* Scale by 1/CNORM(j) to avoid overflow when multiplying x(j) times column j. */ rec /= cnorm[j]; } zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } i__3 = j; zladiv_(&z__1, &x[j], &tjjs); x[i__3].r = z__1.r, x[i__3].i = z__1.i; i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2)); } else { /* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and scale = 0, and compute a solution to A*x = 0. */ i__3 = *n; for (i__ = 1; i__ <= i__3; ++i__) { i__4 = i__; x[i__4].r = 0., x[i__4].i = 0.; /* L100: */ } i__3 = j; x[i__3].r = 1., x[i__3].i = 0.; xj = 1.; *scale = 0.; xmax = 0.; } L110: /* Scale x if necessary to avoid overflow when adding a multiple of column j of A. */ if (xj > 1.) { rec = 1. / xj; if (cnorm[j] > (bignum - xmax) * rec) { /* Scale x by 1/(2*abs(x(j))). */ rec *= .5; zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; } } else if (xj * cnorm[j] > bignum - xmax) { /* Scale x by 1/2. */ zdscal_(n, &c_b2435, &x[1], &c__1); *scale *= .5; } if (upper) { if (j > 1) { /* Compute the update x(1:j-1) := x(1:j-1) - x(j) * A(1:j-1,j) */ i__3 = j - 1; i__4 = j; z__2.r = -x[i__4].r, z__2.i = -x[i__4].i; z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i; zaxpy_(&i__3, &z__1, &a[j * a_dim1 + 1], &c__1, &x[1], &c__1); i__3 = j - 1; i__ = izamax_(&i__3, &x[1], &c__1); i__3 = i__; xmax = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag( &x[i__]), abs(d__2)); } } else { if (j < *n) { /* Compute the update x(j+1:n) := x(j+1:n) - x(j) * A(j+1:n,j) */ i__3 = *n - j; i__4 = j; z__2.r = -x[i__4].r, z__2.i = -x[i__4].i; z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i; zaxpy_(&i__3, &z__1, &a[j + 1 + j * a_dim1], &c__1, & x[j + 1], &c__1); i__3 = *n - j; i__ = j + izamax_(&i__3, &x[j + 1], &c__1); i__3 = i__; xmax = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag( &x[i__]), abs(d__2)); } } /* L120: */ } } else if (lsame_(trans, "T")) { /* Solve A**T * x = b */ i__2 = jlast; i__1 = jinc; for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) { /* Compute x(j) = b(j) - sum A(k,j)*x(k). k<>j */ i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); uscal.r = tscal, uscal.i = 0.; rec = 1. / max(xmax,1.); if (cnorm[j] > (bignum - xj) * rec) { /* If x(j) could overflow, scale x by 1/(2*XMAX). */ rec *= .5; if (nounit) { i__3 = j + j * a_dim1; z__1.r = tscal * a[i__3].r, z__1.i = tscal * a[i__3] .i; tjjs.r = z__1.r, tjjs.i = z__1.i; } else { tjjs.r = tscal, tjjs.i = 0.; } tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2)); if (tjj > 1.) { /* Divide by A(j,j) when scaling x if A(j,j) > 1. Computing MIN */ d__1 = 1., d__2 = rec * tjj; rec = min(d__1,d__2); zladiv_(&z__1, &uscal, &tjjs); uscal.r = z__1.r, uscal.i = z__1.i; } if (rec < 1.) { zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } } csumj.r = 0., csumj.i = 0.; if (uscal.r == 1. && uscal.i == 0.) { /* If the scaling needed for A in the dot product is 1, call ZDOTU to perform the dot product. */ if (upper) { i__3 = j - 1; zdotu_(&z__1, &i__3, &a[j * a_dim1 + 1], &c__1, &x[1], &c__1); csumj.r = z__1.r, csumj.i = z__1.i; } else if (j < *n) { i__3 = *n - j; zdotu_(&z__1, &i__3, &a[j + 1 + j * a_dim1], &c__1, & x[j + 1], &c__1); csumj.r = z__1.r, csumj.i = z__1.i; } } else { /* Otherwise, use in-line code for the dot product. */ if (upper) { i__3 = j - 1; for (i__ = 1; i__ <= i__3; ++i__) { i__4 = i__ + j * a_dim1; z__3.r = a[i__4].r * uscal.r - a[i__4].i * uscal.i, z__3.i = a[i__4].r * uscal.i + a[ i__4].i * uscal.r; i__5 = i__; z__2.r = z__3.r * x[i__5].r - z__3.i * x[i__5].i, z__2.i = z__3.r * x[i__5].i + z__3.i * x[ i__5].r; z__1.r = csumj.r + z__2.r, z__1.i = csumj.i + z__2.i; csumj.r = z__1.r, csumj.i = z__1.i; /* L130: */ } } else if (j < *n) { i__3 = *n; for (i__ = j + 1; i__ <= i__3; ++i__) { i__4 = i__ + j * a_dim1; z__3.r = a[i__4].r * uscal.r - a[i__4].i * uscal.i, z__3.i = a[i__4].r * uscal.i + a[ i__4].i * uscal.r; i__5 = i__; z__2.r = z__3.r * x[i__5].r - z__3.i * x[i__5].i, z__2.i = z__3.r * x[i__5].i + z__3.i * x[ i__5].r; z__1.r = csumj.r + z__2.r, z__1.i = csumj.i + z__2.i; csumj.r = z__1.r, csumj.i = z__1.i; /* L140: */ } } } z__1.r = tscal, z__1.i = 0.; if (uscal.r == z__1.r && uscal.i == z__1.i) { /* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) was not used to scale the dotproduct. */ i__3 = j; i__4 = j; z__1.r = x[i__4].r - csumj.r, z__1.i = x[i__4].i - csumj.i; x[i__3].r = z__1.r, x[i__3].i = z__1.i; i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2)); if (nounit) { i__3 = j + j * a_dim1; z__1.r = tscal * a[i__3].r, z__1.i = tscal * a[i__3] .i; tjjs.r = z__1.r, tjjs.i = z__1.i; } else { tjjs.r = tscal, tjjs.i = 0.; if (tscal == 1.) { goto L160; } } /* Compute x(j) = x(j) / A(j,j), scaling if necessary. */ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2)); if (tjj > smlnum) { /* abs(A(j,j)) > SMLNUM: */ if (tjj < 1.) { if (xj > tjj * bignum) { /* Scale X by 1/abs(x(j)). */ rec = 1. / xj; zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } } i__3 = j; zladiv_(&z__1, &x[j], &tjjs); x[i__3].r = z__1.r, x[i__3].i = z__1.i; } else if (tjj > 0.) { /* 0 < abs(A(j,j)) <= SMLNUM: */ if (xj > tjj * bignum) { /* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */ rec = tjj * bignum / xj; zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } i__3 = j; zladiv_(&z__1, &x[j], &tjjs); x[i__3].r = z__1.r, x[i__3].i = z__1.i; } else { /* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and scale = 0 and compute a solution to A**T *x = 0. */ i__3 = *n; for (i__ = 1; i__ <= i__3; ++i__) { i__4 = i__; x[i__4].r = 0., x[i__4].i = 0.; /* L150: */ } i__3 = j; x[i__3].r = 1., x[i__3].i = 0.; *scale = 0.; xmax = 0.; } L160: ; } else { /* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot product has already been divided by 1/A(j,j). */ i__3 = j; zladiv_(&z__2, &x[j], &tjjs); z__1.r = z__2.r - csumj.r, z__1.i = z__2.i - csumj.i; x[i__3].r = z__1.r, x[i__3].i = z__1.i; } /* Computing MAX */ i__3 = j; d__3 = xmax, d__4 = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); xmax = max(d__3,d__4); /* L170: */ } } else { /* Solve A**H * x = b */ i__1 = jlast; i__2 = jinc; for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Compute x(j) = b(j) - sum A(k,j)*x(k). k<>j */ i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); uscal.r = tscal, uscal.i = 0.; rec = 1. / max(xmax,1.); if (cnorm[j] > (bignum - xj) * rec) { /* If x(j) could overflow, scale x by 1/(2*XMAX). */ rec *= .5; if (nounit) { d_cnjg(&z__2, &a[j + j * a_dim1]); z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i; tjjs.r = z__1.r, tjjs.i = z__1.i; } else { tjjs.r = tscal, tjjs.i = 0.; } tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2)); if (tjj > 1.) { /* Divide by A(j,j) when scaling x if A(j,j) > 1. Computing MIN */ d__1 = 1., d__2 = rec * tjj; rec = min(d__1,d__2); zladiv_(&z__1, &uscal, &tjjs); uscal.r = z__1.r, uscal.i = z__1.i; } if (rec < 1.) { zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } } csumj.r = 0., csumj.i = 0.; if (uscal.r == 1. && uscal.i == 0.) { /* If the scaling needed for A in the dot product is 1, call ZDOTC to perform the dot product. */ if (upper) { i__3 = j - 1; zdotc_(&z__1, &i__3, &a[j * a_dim1 + 1], &c__1, &x[1], &c__1); csumj.r = z__1.r, csumj.i = z__1.i; } else if (j < *n) { i__3 = *n - j; zdotc_(&z__1, &i__3, &a[j + 1 + j * a_dim1], &c__1, & x[j + 1], &c__1); csumj.r = z__1.r, csumj.i = z__1.i; } } else { /* Otherwise, use in-line code for the dot product. */ if (upper) { i__3 = j - 1; for (i__ = 1; i__ <= i__3; ++i__) { d_cnjg(&z__4, &a[i__ + j * a_dim1]); z__3.r = z__4.r * uscal.r - z__4.i * uscal.i, z__3.i = z__4.r * uscal.i + z__4.i * uscal.r; i__4 = i__; z__2.r = z__3.r * x[i__4].r - z__3.i * x[i__4].i, z__2.i = z__3.r * x[i__4].i + z__3.i * x[ i__4].r; z__1.r = csumj.r + z__2.r, z__1.i = csumj.i + z__2.i; csumj.r = z__1.r, csumj.i = z__1.i; /* L180: */ } } else if (j < *n) { i__3 = *n; for (i__ = j + 1; i__ <= i__3; ++i__) { d_cnjg(&z__4, &a[i__ + j * a_dim1]); z__3.r = z__4.r * uscal.r - z__4.i * uscal.i, z__3.i = z__4.r * uscal.i + z__4.i * uscal.r; i__4 = i__; z__2.r = z__3.r * x[i__4].r - z__3.i * x[i__4].i, z__2.i = z__3.r * x[i__4].i + z__3.i * x[ i__4].r; z__1.r = csumj.r + z__2.r, z__1.i = csumj.i + z__2.i; csumj.r = z__1.r, csumj.i = z__1.i; /* L190: */ } } } z__1.r = tscal, z__1.i = 0.; if (uscal.r == z__1.r && uscal.i == z__1.i) { /* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) was not used to scale the dotproduct. */ i__3 = j; i__4 = j; z__1.r = x[i__4].r - csumj.r, z__1.i = x[i__4].i - csumj.i; x[i__3].r = z__1.r, x[i__3].i = z__1.i; i__3 = j; xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2)); if (nounit) { d_cnjg(&z__2, &a[j + j * a_dim1]); z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i; tjjs.r = z__1.r, tjjs.i = z__1.i; } else { tjjs.r = tscal, tjjs.i = 0.; if (tscal == 1.) { goto L210; } } /* Compute x(j) = x(j) / A(j,j), scaling if necessary. */ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2)); if (tjj > smlnum) { /* abs(A(j,j)) > SMLNUM: */ if (tjj < 1.) { if (xj > tjj * bignum) { /* Scale X by 1/abs(x(j)). */ rec = 1. / xj; zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } } i__3 = j; zladiv_(&z__1, &x[j], &tjjs); x[i__3].r = z__1.r, x[i__3].i = z__1.i; } else if (tjj > 0.) { /* 0 < abs(A(j,j)) <= SMLNUM: */ if (xj > tjj * bignum) { /* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */ rec = tjj * bignum / xj; zdscal_(n, &rec, &x[1], &c__1); *scale *= rec; xmax *= rec; } i__3 = j; zladiv_(&z__1, &x[j], &tjjs); x[i__3].r = z__1.r, x[i__3].i = z__1.i; } else { /* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and scale = 0 and compute a solution to A**H *x = 0. */ i__3 = *n; for (i__ = 1; i__ <= i__3; ++i__) { i__4 = i__; x[i__4].r = 0., x[i__4].i = 0.; /* L200: */ } i__3 = j; x[i__3].r = 1., x[i__3].i = 0.; *scale = 0.; xmax = 0.; } L210: ; } else { /* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot product has already been divided by 1/A(j,j). */ i__3 = j; zladiv_(&z__2, &x[j], &tjjs); z__1.r = z__2.r - csumj.r, z__1.i = z__2.i - csumj.i; x[i__3].r = z__1.r, x[i__3].i = z__1.i; } /* Computing MAX */ i__3 = j; d__3 = xmax, d__4 = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); xmax = max(d__3,d__4); /* L220: */ } } *scale /= tscal; } /* Scale the column norms by 1/TSCAL for return. */ if (tscal != 1.) { d__1 = 1. / tscal; dscal_(n, &d__1, &cnorm[1], &c__1); } return 0; /* End of ZLATRS */ } /* zlatrs_ */ /* Subroutine */ int zlauu2_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublereal d__1; doublecomplex z__1; /* Local variables */ static integer i__; static doublereal aii; extern logical lsame_(char *, char *); extern /* Double Complex */ VOID zdotc_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static logical upper; extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_( integer *, doublereal *, doublecomplex *, integer *), zlacgv_( integer *, doublecomplex *, integer *); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLAUU2 computes the product U * U' or L' * L, where the triangular factor U or L is stored in the upper or lower triangular part of the array A. If UPLO = 'U' or 'u' then the upper triangle of the result is stored, overwriting the factor U in A. If UPLO = 'L' or 'l' then the lower triangle of the result is stored, overwriting the factor L in A. This is the unblocked form of the algorithm, calling Level 2 BLAS. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the triangular factor stored in the array A is upper or lower triangular: = 'U': Upper triangular = 'L': Lower triangular N (input) INTEGER The order of the triangular factor U or L. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the triangular factor U or L. On exit, if UPLO = 'U', the upper triangle of A is overwritten with the upper triangle of the product U * U'; if UPLO = 'L', the lower triangle of A is overwritten with the lower triangle of the product L' * L. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLAUU2", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } if (upper) { /* Compute the product U * U'. */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * a_dim1; aii = a[i__2].r; if (i__ < *n) { i__2 = i__ + i__ * a_dim1; i__3 = *n - i__; zdotc_(&z__1, &i__3, &a[i__ + (i__ + 1) * a_dim1], lda, &a[ i__ + (i__ + 1) * a_dim1], lda); d__1 = aii * aii + z__1.r; a[i__2].r = d__1, a[i__2].i = 0.; i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); i__2 = i__ - 1; i__3 = *n - i__; z__1.r = aii, z__1.i = 0.; zgemv_("No transpose", &i__2, &i__3, &c_b57, &a[(i__ + 1) * a_dim1 + 1], lda, &a[i__ + (i__ + 1) * a_dim1], lda, & z__1, &a[i__ * a_dim1 + 1], &c__1); i__2 = *n - i__; zlacgv_(&i__2, &a[i__ + (i__ + 1) * a_dim1], lda); } else { zdscal_(&i__, &aii, &a[i__ * a_dim1 + 1], &c__1); } /* L10: */ } } else { /* Compute the product L' * L. */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + i__ * a_dim1; aii = a[i__2].r; if (i__ < *n) { i__2 = i__ + i__ * a_dim1; i__3 = *n - i__; zdotc_(&z__1, &i__3, &a[i__ + 1 + i__ * a_dim1], &c__1, &a[ i__ + 1 + i__ * a_dim1], &c__1); d__1 = aii * aii + z__1.r; a[i__2].r = d__1, a[i__2].i = 0.; i__2 = i__ - 1; zlacgv_(&i__2, &a[i__ + a_dim1], lda); i__2 = *n - i__; i__3 = i__ - 1; z__1.r = aii, z__1.i = 0.; zgemv_("Conjugate transpose", &i__2, &i__3, &c_b57, &a[i__ + 1 + a_dim1], lda, &a[i__ + 1 + i__ * a_dim1], &c__1, & z__1, &a[i__ + a_dim1], lda); i__2 = i__ - 1; zlacgv_(&i__2, &a[i__ + a_dim1], lda); } else { zdscal_(&i__, &aii, &a[i__ + a_dim1], lda); } /* L20: */ } } return 0; /* End of ZLAUU2 */ } /* zlauu2_ */ /* Subroutine */ int zlauum_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, ib, nb; extern logical lsame_(char *, char *); extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zherk_(char *, char *, integer *, integer *, doublereal *, doublecomplex *, integer *, doublereal *, doublecomplex *, integer *); static logical upper; extern /* Subroutine */ int ztrmm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), zlauu2_(char *, integer *, doublecomplex *, integer *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZLAUUM computes the product U * U' or L' * L, where the triangular factor U or L is stored in the upper or lower triangular part of the array A. If UPLO = 'U' or 'u' then the upper triangle of the result is stored, overwriting the factor U in A. If UPLO = 'L' or 'l' then the lower triangle of the result is stored, overwriting the factor L in A. This is the blocked form of the algorithm, calling Level 3 BLAS. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the triangular factor stored in the array A is upper or lower triangular: = 'U': Upper triangular = 'L': Lower triangular N (input) INTEGER The order of the triangular factor U or L. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the triangular factor U or L. On exit, if UPLO = 'U', the upper triangle of A is overwritten with the upper triangle of the product U * U'; if UPLO = 'L', the lower triangle of A is overwritten with the lower triangle of the product L' * L. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZLAUUM", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Determine the block size for this environment. */ nb = ilaenv_(&c__1, "ZLAUUM", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, ( ftnlen)1); if (nb <= 1 || nb >= *n) { /* Use unblocked code */ zlauu2_(uplo, n, &a[a_offset], lda, info); } else { /* Use blocked code */ if (upper) { /* Compute the product U * U'. */ i__1 = *n; i__2 = nb; for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__3 = nb, i__4 = *n - i__ + 1; ib = min(i__3,i__4); i__3 = i__ - 1; ztrmm_("Right", "Upper", "Conjugate transpose", "Non-unit", & i__3, &ib, &c_b57, &a[i__ + i__ * a_dim1], lda, &a[ i__ * a_dim1 + 1], lda); zlauu2_("Upper", &ib, &a[i__ + i__ * a_dim1], lda, info); if (i__ + ib <= *n) { i__3 = i__ - 1; i__4 = *n - i__ - ib + 1; zgemm_("No transpose", "Conjugate transpose", &i__3, &ib, &i__4, &c_b57, &a[(i__ + ib) * a_dim1 + 1], lda, & a[i__ + (i__ + ib) * a_dim1], lda, &c_b57, &a[i__ * a_dim1 + 1], lda); i__3 = *n - i__ - ib + 1; zherk_("Upper", "No transpose", &ib, &i__3, &c_b1034, &a[ i__ + (i__ + ib) * a_dim1], lda, &c_b1034, &a[i__ + i__ * a_dim1], lda); } /* L10: */ } } else { /* Compute the product L' * L. */ i__2 = *n; i__1 = nb; for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) { /* Computing MIN */ i__3 = nb, i__4 = *n - i__ + 1; ib = min(i__3,i__4); i__3 = i__ - 1; ztrmm_("Left", "Lower", "Conjugate transpose", "Non-unit", & ib, &i__3, &c_b57, &a[i__ + i__ * a_dim1], lda, &a[ i__ + a_dim1], lda); zlauu2_("Lower", &ib, &a[i__ + i__ * a_dim1], lda, info); if (i__ + ib <= *n) { i__3 = i__ - 1; i__4 = *n - i__ - ib + 1; zgemm_("Conjugate transpose", "No transpose", &ib, &i__3, &i__4, &c_b57, &a[i__ + ib + i__ * a_dim1], lda, & a[i__ + ib + a_dim1], lda, &c_b57, &a[i__ + a_dim1], lda); i__3 = *n - i__ - ib + 1; zherk_("Lower", "Conjugate transpose", &ib, &i__3, & c_b1034, &a[i__ + ib + i__ * a_dim1], lda, & c_b1034, &a[i__ + i__ * a_dim1], lda); } /* L20: */ } } } return 0; /* End of ZLAUUM */ } /* zlauum_ */ /* Subroutine */ int zpotf2_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublereal d__1; doublecomplex z__1, z__2; /* Builtin functions */ double sqrt(doublereal); /* Local variables */ static integer j; static doublereal ajj; extern logical lsame_(char *, char *); extern /* Double Complex */ VOID zdotc_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); extern /* Subroutine */ int zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static logical upper; extern logical disnan_(doublereal *); extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_( integer *, doublereal *, doublecomplex *, integer *), zlacgv_( integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZPOTF2 computes the Cholesky factorization of a complex Hermitian positive definite matrix A. The factorization has the form A = U' * U , if UPLO = 'U', or A = L * L', if UPLO = 'L', where U is an upper triangular matrix and L is lower triangular. This is the unblocked version of the algorithm, calling Level 2 BLAS. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the upper or lower triangular part of the Hermitian matrix A is stored. = 'U': Upper triangular = 'L': Lower triangular N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading n by n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if INFO = 0, the factor U or L from the Cholesky factorization A = U'*U or A = L*L'. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value > 0: if INFO = k, the leading minor of order k is not positive definite, and the factorization could not be completed. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZPOTF2", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } if (upper) { /* Compute the Cholesky factorization A = U'*U. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Compute U(J,J) and test for non-positive-definiteness. */ i__2 = j + j * a_dim1; d__1 = a[i__2].r; i__3 = j - 1; zdotc_(&z__2, &i__3, &a[j * a_dim1 + 1], &c__1, &a[j * a_dim1 + 1] , &c__1); z__1.r = d__1 - z__2.r, z__1.i = -z__2.i; ajj = z__1.r; if (ajj <= 0. || disnan_(&ajj)) { i__2 = j + j * a_dim1; a[i__2].r = ajj, a[i__2].i = 0.; goto L30; } ajj = sqrt(ajj); i__2 = j + j * a_dim1; a[i__2].r = ajj, a[i__2].i = 0.; /* Compute elements J+1:N of row J. */ if (j < *n) { i__2 = j - 1; zlacgv_(&i__2, &a[j * a_dim1 + 1], &c__1); i__2 = j - 1; i__3 = *n - j; z__1.r = -1., z__1.i = -0.; zgemv_("Transpose", &i__2, &i__3, &z__1, &a[(j + 1) * a_dim1 + 1], lda, &a[j * a_dim1 + 1], &c__1, &c_b57, &a[j + ( j + 1) * a_dim1], lda); i__2 = j - 1; zlacgv_(&i__2, &a[j * a_dim1 + 1], &c__1); i__2 = *n - j; d__1 = 1. / ajj; zdscal_(&i__2, &d__1, &a[j + (j + 1) * a_dim1], lda); } /* L10: */ } } else { /* Compute the Cholesky factorization A = L*L'. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Compute L(J,J) and test for non-positive-definiteness. */ i__2 = j + j * a_dim1; d__1 = a[i__2].r; i__3 = j - 1; zdotc_(&z__2, &i__3, &a[j + a_dim1], lda, &a[j + a_dim1], lda); z__1.r = d__1 - z__2.r, z__1.i = -z__2.i; ajj = z__1.r; if (ajj <= 0. || disnan_(&ajj)) { i__2 = j + j * a_dim1; a[i__2].r = ajj, a[i__2].i = 0.; goto L30; } ajj = sqrt(ajj); i__2 = j + j * a_dim1; a[i__2].r = ajj, a[i__2].i = 0.; /* Compute elements J+1:N of column J. */ if (j < *n) { i__2 = j - 1; zlacgv_(&i__2, &a[j + a_dim1], lda); i__2 = *n - j; i__3 = j - 1; z__1.r = -1., z__1.i = -0.; zgemv_("No transpose", &i__2, &i__3, &z__1, &a[j + 1 + a_dim1] , lda, &a[j + a_dim1], lda, &c_b57, &a[j + 1 + j * a_dim1], &c__1); i__2 = j - 1; zlacgv_(&i__2, &a[j + a_dim1], lda); i__2 = *n - j; d__1 = 1. / ajj; zdscal_(&i__2, &d__1, &a[j + 1 + j * a_dim1], &c__1); } /* L20: */ } } goto L40; L30: *info = j; L40: return 0; /* End of ZPOTF2 */ } /* zpotf2_ */ /* Subroutine */ int zpotrf_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; doublecomplex z__1; /* Local variables */ static integer j, jb, nb; extern logical lsame_(char *, char *); extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), zherk_(char *, char *, integer *, integer *, doublereal *, doublecomplex *, integer *, doublereal *, doublecomplex *, integer *); static logical upper; extern /* Subroutine */ int ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), zpotf2_(char *, integer *, doublecomplex *, integer *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZPOTRF computes the Cholesky factorization of a complex Hermitian positive definite matrix A. The factorization has the form A = U**H * U, if UPLO = 'U', or A = L * L**H, if UPLO = 'L', where U is an upper triangular matrix and L is lower triangular. This is the block version of the algorithm, calling Level 3 BLAS. Arguments ========= UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the Hermitian matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if INFO = 0, the factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, the leading minor of order i is not positive definite, and the factorization could not be completed. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZPOTRF", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Determine the block size for this environment. */ nb = ilaenv_(&c__1, "ZPOTRF", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, ( ftnlen)1); if (nb <= 1 || nb >= *n) { /* Use unblocked code. */ zpotf2_(uplo, n, &a[a_offset], lda, info); } else { /* Use blocked code. */ if (upper) { /* Compute the Cholesky factorization A = U'*U. */ i__1 = *n; i__2 = nb; for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Update and factorize the current diagonal block and test for non-positive-definiteness. Computing MIN */ i__3 = nb, i__4 = *n - j + 1; jb = min(i__3,i__4); i__3 = j - 1; zherk_("Upper", "Conjugate transpose", &jb, &i__3, &c_b1276, & a[j * a_dim1 + 1], lda, &c_b1034, &a[j + j * a_dim1], lda); zpotf2_("Upper", &jb, &a[j + j * a_dim1], lda, info); if (*info != 0) { goto L30; } if (j + jb <= *n) { /* Compute the current block row. */ i__3 = *n - j - jb + 1; i__4 = j - 1; z__1.r = -1., z__1.i = -0.; zgemm_("Conjugate transpose", "No transpose", &jb, &i__3, &i__4, &z__1, &a[j * a_dim1 + 1], lda, &a[(j + jb) * a_dim1 + 1], lda, &c_b57, &a[j + (j + jb) * a_dim1], lda); i__3 = *n - j - jb + 1; ztrsm_("Left", "Upper", "Conjugate transpose", "Non-unit", &jb, &i__3, &c_b57, &a[j + j * a_dim1], lda, &a[ j + (j + jb) * a_dim1], lda); } /* L10: */ } } else { /* Compute the Cholesky factorization A = L*L'. */ i__2 = *n; i__1 = nb; for (j = 1; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) { /* Update and factorize the current diagonal block and test for non-positive-definiteness. Computing MIN */ i__3 = nb, i__4 = *n - j + 1; jb = min(i__3,i__4); i__3 = j - 1; zherk_("Lower", "No transpose", &jb, &i__3, &c_b1276, &a[j + a_dim1], lda, &c_b1034, &a[j + j * a_dim1], lda); zpotf2_("Lower", &jb, &a[j + j * a_dim1], lda, info); if (*info != 0) { goto L30; } if (j + jb <= *n) { /* Compute the current block column. */ i__3 = *n - j - jb + 1; i__4 = j - 1; z__1.r = -1., z__1.i = -0.; zgemm_("No transpose", "Conjugate transpose", &i__3, &jb, &i__4, &z__1, &a[j + jb + a_dim1], lda, &a[j + a_dim1], lda, &c_b57, &a[j + jb + j * a_dim1], lda); i__3 = *n - j - jb + 1; ztrsm_("Right", "Lower", "Conjugate transpose", "Non-unit" , &i__3, &jb, &c_b57, &a[j + j * a_dim1], lda, &a[ j + jb + j * a_dim1], lda); } /* L20: */ } } } goto L40; L30: *info = *info + j - 1; L40: return 0; /* End of ZPOTRF */ } /* zpotrf_ */ /* Subroutine */ int zpotri_(char *uplo, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1; /* Local variables */ extern logical lsame_(char *, char *); extern /* Subroutine */ int xerbla_(char *, integer *), zlauum_( char *, integer *, doublecomplex *, integer *, integer *), ztrtri_(char *, char *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZPOTRI computes the inverse of a complex Hermitian positive definite matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by ZPOTRF. Arguments ========= UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, as computed by ZPOTRF. On exit, the upper or lower triangle of the (Hermitian) inverse of A, overwriting the input factor U or L. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, the (i,i) element of the factor U or L is zero, and the inverse could not be computed. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*lda < max(1,*n)) { *info = -4; } if (*info != 0) { i__1 = -(*info); xerbla_("ZPOTRI", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Invert the triangular Cholesky factor U or L. */ ztrtri_(uplo, "Non-unit", n, &a[a_offset], lda, info); if (*info > 0) { return 0; } /* Form inv(U)*inv(U)' or inv(L)'*inv(L). */ zlauum_(uplo, n, &a[a_offset], lda, info); return 0; /* End of ZPOTRI */ } /* zpotri_ */ /* Subroutine */ int zpotrs_(char *uplo, integer *n, integer *nrhs, doublecomplex *a, integer *lda, doublecomplex *b, integer *ldb, integer *info) { /* System generated locals */ integer a_dim1, a_offset, b_dim1, b_offset, i__1; /* Local variables */ extern logical lsame_(char *, char *); static logical upper; extern /* Subroutine */ int ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZPOTRS solves a system of linear equations A*X = B with a Hermitian positive definite matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by ZPOTRF. Arguments ========= UPLO (input) CHARACTER*1 = 'U': Upper triangle of A is stored; = 'L': Lower triangle of A is stored. N (input) INTEGER The order of the matrix A. N >= 0. NRHS (input) INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. A (input) COMPLEX*16 array, dimension (LDA,N) The triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, as computed by ZPOTRF. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) On entry, the right hand side matrix B. On exit, the solution matrix X. LDB (input) INTEGER The leading dimension of the array B. LDB >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; b_dim1 = *ldb; b_offset = 1 + b_dim1; b -= b_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*nrhs < 0) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } else if (*ldb < max(1,*n)) { *info = -7; } if (*info != 0) { i__1 = -(*info); xerbla_("ZPOTRS", &i__1); return 0; } /* Quick return if possible */ if (*n == 0 || *nrhs == 0) { return 0; } if (upper) { /* Solve A*X = B where A = U'*U. Solve U'*X = B, overwriting B with X. */ ztrsm_("Left", "Upper", "Conjugate transpose", "Non-unit", n, nrhs, & c_b57, &a[a_offset], lda, &b[b_offset], ldb); /* Solve U*X = B, overwriting B with X. */ ztrsm_("Left", "Upper", "No transpose", "Non-unit", n, nrhs, &c_b57, & a[a_offset], lda, &b[b_offset], ldb); } else { /* Solve A*X = B where A = L*L'. Solve L*X = B, overwriting B with X. */ ztrsm_("Left", "Lower", "No transpose", "Non-unit", n, nrhs, &c_b57, & a[a_offset], lda, &b[b_offset], ldb); /* Solve L'*X = B, overwriting B with X. */ ztrsm_("Left", "Lower", "Conjugate transpose", "Non-unit", n, nrhs, & c_b57, &a[a_offset], lda, &b[b_offset], ldb); } return 0; /* End of ZPOTRS */ } /* zpotrs_ */ /* Subroutine */ int zrot_(integer *n, doublecomplex *cx, integer *incx, doublecomplex *cy, integer *incy, doublereal *c__, doublecomplex *s) { /* System generated locals */ integer i__1, i__2, i__3, i__4; doublecomplex z__1, z__2, z__3, z__4; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, ix, iy; static doublecomplex stemp; /* -- LAPACK auxiliary routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZROT applies a plane rotation, where the cos (C) is real and the sin (S) is complex, and the vectors CX and CY are complex. Arguments ========= N (input) INTEGER The number of elements in the vectors CX and CY. CX (input/output) COMPLEX*16 array, dimension (N) On input, the vector X. On output, CX is overwritten with C*X + S*Y. INCX (input) INTEGER The increment between successive values of CY. INCX <> 0. CY (input/output) COMPLEX*16 array, dimension (N) On input, the vector Y. On output, CY is overwritten with -CONJG(S)*X + C*Y. INCY (input) INTEGER The increment between successive values of CY. INCX <> 0. C (input) DOUBLE PRECISION S (input) COMPLEX*16 C and S define a rotation [ C S ] [ -conjg(S) C ] where C*C + S*CONJG(S) = 1.0. ===================================================================== */ /* Parameter adjustments */ --cy; --cx; /* Function Body */ if (*n <= 0) { return 0; } if (*incx == 1 && *incy == 1) { goto L20; } /* Code for unequal increments or equal increments not equal to 1 */ ix = 1; iy = 1; if (*incx < 0) { ix = (-(*n) + 1) * *incx + 1; } if (*incy < 0) { iy = (-(*n) + 1) * *incy + 1; } i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = ix; z__2.r = *c__ * cx[i__2].r, z__2.i = *c__ * cx[i__2].i; i__3 = iy; z__3.r = s->r * cy[i__3].r - s->i * cy[i__3].i, z__3.i = s->r * cy[ i__3].i + s->i * cy[i__3].r; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; stemp.r = z__1.r, stemp.i = z__1.i; i__2 = iy; i__3 = iy; z__2.r = *c__ * cy[i__3].r, z__2.i = *c__ * cy[i__3].i; d_cnjg(&z__4, s); i__4 = ix; z__3.r = z__4.r * cx[i__4].r - z__4.i * cx[i__4].i, z__3.i = z__4.r * cx[i__4].i + z__4.i * cx[i__4].r; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; cy[i__2].r = z__1.r, cy[i__2].i = z__1.i; i__2 = ix; cx[i__2].r = stemp.r, cx[i__2].i = stemp.i; ix += *incx; iy += *incy; /* L10: */ } return 0; /* Code for both increments equal to 1 */ L20: i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__; z__2.r = *c__ * cx[i__2].r, z__2.i = *c__ * cx[i__2].i; i__3 = i__; z__3.r = s->r * cy[i__3].r - s->i * cy[i__3].i, z__3.i = s->r * cy[ i__3].i + s->i * cy[i__3].r; z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; stemp.r = z__1.r, stemp.i = z__1.i; i__2 = i__; i__3 = i__; z__2.r = *c__ * cy[i__3].r, z__2.i = *c__ * cy[i__3].i; d_cnjg(&z__4, s); i__4 = i__; z__3.r = z__4.r * cx[i__4].r - z__4.i * cx[i__4].i, z__3.i = z__4.r * cx[i__4].i + z__4.i * cx[i__4].r; z__1.r = z__2.r - z__3.r, z__1.i = z__2.i - z__3.i; cy[i__2].r = z__1.r, cy[i__2].i = z__1.i; i__2 = i__; cx[i__2].r = stemp.r, cx[i__2].i = stemp.i; /* L30: */ } return 0; } /* zrot_ */ /* Subroutine */ int zstedc_(char *compz, integer *n, doublereal *d__, doublereal *e, doublecomplex *z__, integer *ldz, doublecomplex *work, integer *lwork, doublereal *rwork, integer *lrwork, integer *iwork, integer *liwork, integer *info) { /* System generated locals */ integer z_dim1, z_offset, i__1, i__2, i__3, i__4; doublereal d__1, d__2; /* Builtin functions */ double log(doublereal); integer pow_ii(integer *, integer *); double sqrt(doublereal); /* Local variables */ static integer i__, j, k, m; static doublereal p; static integer ii, ll, lgn; static doublereal eps, tiny; extern logical lsame_(char *, char *); static integer lwmin, start; extern /* Subroutine */ int zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), zlaed0_(integer *, integer *, doublereal *, doublereal *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, integer *, integer *); extern /* Subroutine */ int dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *), dstedc_(char *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, integer *, integer *, integer *), dlaset_( char *, integer *, integer *, doublereal *, doublereal *, doublereal *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static integer finish; extern doublereal dlanst_(char *, integer *, doublereal *, doublereal *); extern /* Subroutine */ int dsterf_(integer *, doublereal *, doublereal *, integer *), zlacrm_(integer *, integer *, doublecomplex *, integer *, doublereal *, integer *, doublecomplex *, integer *, doublereal *); static integer liwmin, icompz; extern /* Subroutine */ int dsteqr_(char *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *), zlacpy_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static doublereal orgnrm; static integer lrwmin; static logical lquery; static integer smlsiz; extern /* Subroutine */ int zsteqr_(char *, integer *, doublereal *, doublereal *, doublecomplex *, integer *, doublereal *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZSTEDC computes all eigenvalues and, optionally, eigenvectors of a symmetric tridiagonal matrix using the divide and conquer method. The eigenvectors of a full or band complex Hermitian matrix can also be found if ZHETRD or ZHPTRD or ZHBTRD has been used to reduce this matrix to tridiagonal form. This code makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. See DLAED3 for details. Arguments ========= COMPZ (input) CHARACTER*1 = 'N': Compute eigenvalues only. = 'I': Compute eigenvectors of tridiagonal matrix also. = 'V': Compute eigenvectors of original Hermitian matrix also. On entry, Z contains the unitary matrix used to reduce the original matrix to tridiagonal form. N (input) INTEGER The dimension of the symmetric tridiagonal matrix. N >= 0. D (input/output) DOUBLE PRECISION array, dimension (N) On entry, the diagonal elements of the tridiagonal matrix. On exit, if INFO = 0, the eigenvalues in ascending order. E (input/output) DOUBLE PRECISION array, dimension (N-1) On entry, the subdiagonal elements of the tridiagonal matrix. On exit, E has been destroyed. Z (input/output) COMPLEX*16 array, dimension (LDZ,N) On entry, if COMPZ = 'V', then Z contains the unitary matrix used in the reduction to tridiagonal form. On exit, if INFO = 0, then if COMPZ = 'V', Z contains the orthonormal eigenvectors of the original Hermitian matrix, and if COMPZ = 'I', Z contains the orthonormal eigenvectors of the symmetric tridiagonal matrix. If COMPZ = 'N', then Z is not referenced. LDZ (input) INTEGER The leading dimension of the array Z. LDZ >= 1. If eigenvectors are desired, then LDZ >= max(1,N). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If COMPZ = 'N' or 'I', or N <= 1, LWORK must be at least 1. If COMPZ = 'V' and N > 1, LWORK must be at least N*N. Note that for COMPZ = 'V', then if N is less than or equal to the minimum divide size, usually 25, then LWORK need only be 1. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. RWORK (workspace/output) DOUBLE PRECISION array, dimension (LRWORK) On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK. LRWORK (input) INTEGER The dimension of the array RWORK. If COMPZ = 'N' or N <= 1, LRWORK must be at least 1. If COMPZ = 'V' and N > 1, LRWORK must be at least 1 + 3*N + 2*N*lg N + 3*N**2 , where lg( N ) = smallest integer k such that 2**k >= N. If COMPZ = 'I' and N > 1, LRWORK must be at least 1 + 4*N + 2*N**2 . Note that for COMPZ = 'I' or 'V', then if N is less than or equal to the minimum divide size, usually 25, then LRWORK need only be max(1,2*(N-1)). If LRWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. IWORK (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. LIWORK (input) INTEGER The dimension of the array IWORK. If COMPZ = 'N' or N <= 1, LIWORK must be at least 1. If COMPZ = 'V' or N > 1, LIWORK must be at least 6 + 6*N + 5*N*lg N. If COMPZ = 'I' or N > 1, LIWORK must be at least 3 + 5*N . Note that for COMPZ = 'I' or 'V', then if N is less than or equal to the minimum divide size, usually 25, then LIWORK need only be 1. If LIWORK = -1, then a workspace query is assumed; the routine only calculates the optimal sizes of the WORK, RWORK and IWORK arrays, returns these values as the first entries of the WORK, RWORK and IWORK arrays, and no error message related to LWORK or LRWORK or LIWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: The algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). Further Details =============== Based on contributions by Jeff Rutter, Computer Science Division, University of California at Berkeley, USA ===================================================================== Test the input parameters. */ /* Parameter adjustments */ --d__; --e; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --work; --rwork; --iwork; /* Function Body */ *info = 0; lquery = *lwork == -1 || *lrwork == -1 || *liwork == -1; if (lsame_(compz, "N")) { icompz = 0; } else if (lsame_(compz, "V")) { icompz = 1; } else if (lsame_(compz, "I")) { icompz = 2; } else { icompz = -1; } if (icompz < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*ldz < 1 || icompz > 0 && *ldz < max(1,*n)) { *info = -6; } if (*info == 0) { /* Compute the workspace requirements */ smlsiz = ilaenv_(&c__9, "ZSTEDC", " ", &c__0, &c__0, &c__0, &c__0, ( ftnlen)6, (ftnlen)1); if (*n <= 1 || icompz == 0) { lwmin = 1; liwmin = 1; lrwmin = 1; } else if (*n <= smlsiz) { lwmin = 1; liwmin = 1; lrwmin = *n - 1 << 1; } else if (icompz == 1) { lgn = (integer) (log((doublereal) (*n)) / log(2.)); if (pow_ii(&c__2, &lgn) < *n) { ++lgn; } if (pow_ii(&c__2, &lgn) < *n) { ++lgn; } lwmin = *n * *n; /* Computing 2nd power */ i__1 = *n; lrwmin = *n * 3 + 1 + (*n << 1) * lgn + i__1 * i__1 * 3; liwmin = *n * 6 + 6 + *n * 5 * lgn; } else if (icompz == 2) { lwmin = 1; /* Computing 2nd power */ i__1 = *n; lrwmin = (*n << 2) + 1 + (i__1 * i__1 << 1); liwmin = *n * 5 + 3; } work[1].r = (doublereal) lwmin, work[1].i = 0.; rwork[1] = (doublereal) lrwmin; iwork[1] = liwmin; if (*lwork < lwmin && ! lquery) { *info = -8; } else if (*lrwork < lrwmin && ! lquery) { *info = -10; } else if (*liwork < liwmin && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("ZSTEDC", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } if (*n == 1) { if (icompz != 0) { i__1 = z_dim1 + 1; z__[i__1].r = 1., z__[i__1].i = 0.; } return 0; } /* If the following conditional clause is removed, then the routine will use the Divide and Conquer routine to compute only the eigenvalues, which requires (3N + 3N**2) real workspace and (2 + 5N + 2N lg(N)) integer workspace. Since on many architectures DSTERF is much faster than any other algorithm for finding eigenvalues only, it is used here as the default. If the conditional clause is removed, then information on the size of workspace needs to be changed. If COMPZ = 'N', use DSTERF to compute the eigenvalues. */ if (icompz == 0) { dsterf_(n, &d__[1], &e[1], info); goto L70; } /* If N is smaller than the minimum divide size (SMLSIZ+1), then solve the problem with another solver. */ if (*n <= smlsiz) { zsteqr_(compz, n, &d__[1], &e[1], &z__[z_offset], ldz, &rwork[1], info); } else { /* If COMPZ = 'I', we simply call DSTEDC instead. */ if (icompz == 2) { dlaset_("Full", n, n, &c_b328, &c_b1034, &rwork[1], n); ll = *n * *n + 1; i__1 = *lrwork - ll + 1; dstedc_("I", n, &d__[1], &e[1], &rwork[1], n, &rwork[ll], &i__1, & iwork[1], liwork, info); i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * z_dim1; i__4 = (j - 1) * *n + i__; z__[i__3].r = rwork[i__4], z__[i__3].i = 0.; /* L10: */ } /* L20: */ } goto L70; } /* From now on, only option left to be handled is COMPZ = 'V', i.e. ICOMPZ = 1. Scale. */ orgnrm = dlanst_("M", n, &d__[1], &e[1]); if (orgnrm == 0.) { goto L70; } eps = EPSILON; start = 1; /* while ( START <= N ) */ L30: if (start <= *n) { /* Let FINISH be the position of the next subdiagonal entry such that E( FINISH ) <= TINY or FINISH = N if no such subdiagonal exists. The matrix identified by the elements between START and FINISH constitutes an independent sub-problem. */ finish = start; L40: if (finish < *n) { tiny = eps * sqrt((d__1 = d__[finish], abs(d__1))) * sqrt(( d__2 = d__[finish + 1], abs(d__2))); if ((d__1 = e[finish], abs(d__1)) > tiny) { ++finish; goto L40; } } /* (Sub) Problem determined. Compute its size and solve it. */ m = finish - start + 1; if (m > smlsiz) { /* Scale. */ orgnrm = dlanst_("M", &m, &d__[start], &e[start]); dlascl_("G", &c__0, &c__0, &orgnrm, &c_b1034, &m, &c__1, &d__[ start], &m, info); i__1 = m - 1; i__2 = m - 1; dlascl_("G", &c__0, &c__0, &orgnrm, &c_b1034, &i__1, &c__1, & e[start], &i__2, info); zlaed0_(n, &m, &d__[start], &e[start], &z__[start * z_dim1 + 1], ldz, &work[1], n, &rwork[1], &iwork[1], info); if (*info > 0) { *info = (*info / (m + 1) + start - 1) * (*n + 1) + *info % (m + 1) + start - 1; goto L70; } /* Scale back. */ dlascl_("G", &c__0, &c__0, &c_b1034, &orgnrm, &m, &c__1, &d__[ start], &m, info); } else { dsteqr_("I", &m, &d__[start], &e[start], &rwork[1], &m, & rwork[m * m + 1], info); zlacrm_(n, &m, &z__[start * z_dim1 + 1], ldz, &rwork[1], &m, & work[1], n, &rwork[m * m + 1]); zlacpy_("A", n, &m, &work[1], n, &z__[start * z_dim1 + 1], ldz); if (*info > 0) { *info = start * (*n + 1) + finish; goto L70; } } start = finish + 1; goto L30; } /* endwhile If the problem split any number of times, then the eigenvalues will not be properly ordered. Here we permute the eigenvalues (and the associated eigenvectors) into ascending order. */ if (m != *n) { /* Use Selection Sort to minimize swaps of eigenvectors */ i__1 = *n; for (ii = 2; ii <= i__1; ++ii) { i__ = ii - 1; k = i__; p = d__[i__]; i__2 = *n; for (j = ii; j <= i__2; ++j) { if (d__[j] < p) { k = j; p = d__[j]; } /* L50: */ } if (k != i__) { d__[k] = d__[i__]; d__[i__] = p; zswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[k * z_dim1 + 1], &c__1); } /* L60: */ } } } L70: work[1].r = (doublereal) lwmin, work[1].i = 0.; rwork[1] = (doublereal) lrwmin; iwork[1] = liwmin; return 0; /* End of ZSTEDC */ } /* zstedc_ */ /* Subroutine */ int zsteqr_(char *compz, integer *n, doublereal *d__, doublereal *e, doublecomplex *z__, integer *ldz, doublereal *work, integer *info) { /* System generated locals */ integer z_dim1, z_offset, i__1, i__2; doublereal d__1, d__2; /* Builtin functions */ double sqrt(doublereal), d_sign(doublereal *, doublereal *); /* Local variables */ static doublereal b, c__, f, g; static integer i__, j, k, l, m; static doublereal p, r__, s; static integer l1, ii, mm, lm1, mm1, nm1; static doublereal rt1, rt2, eps; static integer lsv; static doublereal tst, eps2; static integer lend, jtot; extern /* Subroutine */ int dlae2_(doublereal *, doublereal *, doublereal *, doublereal *, doublereal *); extern logical lsame_(char *, char *); static doublereal anorm; extern /* Subroutine */ int zlasr_(char *, char *, char *, integer *, integer *, doublereal *, doublereal *, doublecomplex *, integer *), zswap_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), dlaev2_(doublereal *, doublereal *, doublereal *, doublereal *, doublereal *, doublereal *, doublereal *); static integer lendm1, lendp1; static integer iscale; extern /* Subroutine */ int dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *); static doublereal safmin; extern /* Subroutine */ int dlartg_(doublereal *, doublereal *, doublereal *, doublereal *, doublereal *); static doublereal safmax; extern /* Subroutine */ int xerbla_(char *, integer *); extern doublereal dlanst_(char *, integer *, doublereal *, doublereal *); extern /* Subroutine */ int dlasrt_(char *, integer *, doublereal *, integer *); static integer lendsv; static doublereal ssfmin; static integer nmaxit, icompz; static doublereal ssfmax; extern /* Subroutine */ int zlaset_(char *, integer *, integer *, doublecomplex *, doublecomplex *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZSTEQR computes all eigenvalues and, optionally, eigenvectors of a symmetric tridiagonal matrix using the implicit QL or QR method. The eigenvectors of a full or band complex Hermitian matrix can also be found if ZHETRD or ZHPTRD or ZHBTRD has been used to reduce this matrix to tridiagonal form. Arguments ========= COMPZ (input) CHARACTER*1 = 'N': Compute eigenvalues only. = 'V': Compute eigenvalues and eigenvectors of the original Hermitian matrix. On entry, Z must contain the unitary matrix used to reduce the original matrix to tridiagonal form. = 'I': Compute eigenvalues and eigenvectors of the tridiagonal matrix. Z is initialized to the identity matrix. N (input) INTEGER The order of the matrix. N >= 0. D (input/output) DOUBLE PRECISION array, dimension (N) On entry, the diagonal elements of the tridiagonal matrix. On exit, if INFO = 0, the eigenvalues in ascending order. E (input/output) DOUBLE PRECISION array, dimension (N-1) On entry, the (n-1) subdiagonal elements of the tridiagonal matrix. On exit, E has been destroyed. Z (input/output) COMPLEX*16 array, dimension (LDZ, N) On entry, if COMPZ = 'V', then Z contains the unitary matrix used in the reduction to tridiagonal form. On exit, if INFO = 0, then if COMPZ = 'V', Z contains the orthonormal eigenvectors of the original Hermitian matrix, and if COMPZ = 'I', Z contains the orthonormal eigenvectors of the symmetric tridiagonal matrix. If COMPZ = 'N', then Z is not referenced. LDZ (input) INTEGER The leading dimension of the array Z. LDZ >= 1, and if eigenvectors are desired, then LDZ >= max(1,N). WORK (workspace) DOUBLE PRECISION array, dimension (max(1,2*N-2)) If COMPZ = 'N', then WORK is not referenced. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: the algorithm has failed to find all the eigenvalues in a total of 30*N iterations; if INFO = i, then i elements of E have not converged to zero; on exit, D and E contain the elements of a symmetric tridiagonal matrix which is unitarily similar to the original matrix. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ --d__; --e; z_dim1 = *ldz; z_offset = 1 + z_dim1; z__ -= z_offset; --work; /* Function Body */ *info = 0; if (lsame_(compz, "N")) { icompz = 0; } else if (lsame_(compz, "V")) { icompz = 1; } else if (lsame_(compz, "I")) { icompz = 2; } else { icompz = -1; } if (icompz < 0) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*ldz < 1 || icompz > 0 && *ldz < max(1,*n)) { *info = -6; } if (*info != 0) { i__1 = -(*info); xerbla_("ZSTEQR", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } if (*n == 1) { if (icompz == 2) { i__1 = z_dim1 + 1; z__[i__1].r = 1., z__[i__1].i = 0.; } return 0; } /* Determine the unit roundoff and over/underflow thresholds. */ eps = EPSILON; /* Computing 2nd power */ d__1 = eps; eps2 = d__1 * d__1; safmin = SAFEMINIMUM; safmax = 1. / safmin; ssfmax = sqrt(safmax) / 3.; ssfmin = sqrt(safmin) / eps2; /* Compute the eigenvalues and eigenvectors of the tridiagonal matrix. */ if (icompz == 2) { zlaset_("Full", n, n, &c_b56, &c_b57, &z__[z_offset], ldz); } nmaxit = *n * 30; jtot = 0; /* Determine where the matrix splits and choose QL or QR iteration for each block, according to whether top or bottom diagonal element is smaller. */ l1 = 1; nm1 = *n - 1; L10: if (l1 > *n) { goto L160; } if (l1 > 1) { e[l1 - 1] = 0.; } if (l1 <= nm1) { i__1 = nm1; for (m = l1; m <= i__1; ++m) { tst = (d__1 = e[m], abs(d__1)); if (tst == 0.) { goto L30; } if (tst <= sqrt((d__1 = d__[m], abs(d__1))) * sqrt((d__2 = d__[m + 1], abs(d__2))) * eps) { e[m] = 0.; goto L30; } /* L20: */ } } m = *n; L30: l = l1; lsv = l; lend = m; lendsv = lend; l1 = m + 1; if (lend == l) { goto L10; } /* Scale submatrix in rows and columns L to LEND */ i__1 = lend - l + 1; anorm = dlanst_("I", &i__1, &d__[l], &e[l]); iscale = 0; if (anorm == 0.) { goto L10; } if (anorm > ssfmax) { iscale = 1; i__1 = lend - l + 1; dlascl_("G", &c__0, &c__0, &anorm, &ssfmax, &i__1, &c__1, &d__[l], n, info); i__1 = lend - l; dlascl_("G", &c__0, &c__0, &anorm, &ssfmax, &i__1, &c__1, &e[l], n, info); } else if (anorm < ssfmin) { iscale = 2; i__1 = lend - l + 1; dlascl_("G", &c__0, &c__0, &anorm, &ssfmin, &i__1, &c__1, &d__[l], n, info); i__1 = lend - l; dlascl_("G", &c__0, &c__0, &anorm, &ssfmin, &i__1, &c__1, &e[l], n, info); } /* Choose between QL and QR iteration */ if ((d__1 = d__[lend], abs(d__1)) < (d__2 = d__[l], abs(d__2))) { lend = lsv; l = lendsv; } if (lend > l) { /* QL Iteration Look for small subdiagonal element. */ L40: if (l != lend) { lendm1 = lend - 1; i__1 = lendm1; for (m = l; m <= i__1; ++m) { /* Computing 2nd power */ d__2 = (d__1 = e[m], abs(d__1)); tst = d__2 * d__2; if (tst <= eps2 * (d__1 = d__[m], abs(d__1)) * (d__2 = d__[m + 1], abs(d__2)) + safmin) { goto L60; } /* L50: */ } } m = lend; L60: if (m < lend) { e[m] = 0.; } p = d__[l]; if (m == l) { goto L80; } /* If remaining matrix is 2-by-2, use DLAE2 or SLAEV2 to compute its eigensystem. */ if (m == l + 1) { if (icompz > 0) { dlaev2_(&d__[l], &e[l], &d__[l + 1], &rt1, &rt2, &c__, &s); work[l] = c__; work[*n - 1 + l] = s; zlasr_("R", "V", "B", n, &c__2, &work[l], &work[*n - 1 + l], & z__[l * z_dim1 + 1], ldz); } else { dlae2_(&d__[l], &e[l], &d__[l + 1], &rt1, &rt2); } d__[l] = rt1; d__[l + 1] = rt2; e[l] = 0.; l += 2; if (l <= lend) { goto L40; } goto L140; } if (jtot == nmaxit) { goto L140; } ++jtot; /* Form shift. */ g = (d__[l + 1] - p) / (e[l] * 2.); r__ = dlapy2_(&g, &c_b1034); g = d__[m] - p + e[l] / (g + d_sign(&r__, &g)); s = 1.; c__ = 1.; p = 0.; /* Inner loop */ mm1 = m - 1; i__1 = l; for (i__ = mm1; i__ >= i__1; --i__) { f = s * e[i__]; b = c__ * e[i__]; dlartg_(&g, &f, &c__, &s, &r__); if (i__ != m - 1) { e[i__ + 1] = r__; } g = d__[i__ + 1] - p; r__ = (d__[i__] - g) * s + c__ * 2. * b; p = s * r__; d__[i__ + 1] = g + p; g = c__ * r__ - b; /* If eigenvectors are desired, then save rotations. */ if (icompz > 0) { work[i__] = c__; work[*n - 1 + i__] = -s; } /* L70: */ } /* If eigenvectors are desired, then apply saved rotations. */ if (icompz > 0) { mm = m - l + 1; zlasr_("R", "V", "B", n, &mm, &work[l], &work[*n - 1 + l], &z__[l * z_dim1 + 1], ldz); } d__[l] -= p; e[l] = g; goto L40; /* Eigenvalue found. */ L80: d__[l] = p; ++l; if (l <= lend) { goto L40; } goto L140; } else { /* QR Iteration Look for small superdiagonal element. */ L90: if (l != lend) { lendp1 = lend + 1; i__1 = lendp1; for (m = l; m >= i__1; --m) { /* Computing 2nd power */ d__2 = (d__1 = e[m - 1], abs(d__1)); tst = d__2 * d__2; if (tst <= eps2 * (d__1 = d__[m], abs(d__1)) * (d__2 = d__[m - 1], abs(d__2)) + safmin) { goto L110; } /* L100: */ } } m = lend; L110: if (m > lend) { e[m - 1] = 0.; } p = d__[l]; if (m == l) { goto L130; } /* If remaining matrix is 2-by-2, use DLAE2 or SLAEV2 to compute its eigensystem. */ if (m == l - 1) { if (icompz > 0) { dlaev2_(&d__[l - 1], &e[l - 1], &d__[l], &rt1, &rt2, &c__, &s) ; work[m] = c__; work[*n - 1 + m] = s; zlasr_("R", "V", "F", n, &c__2, &work[m], &work[*n - 1 + m], & z__[(l - 1) * z_dim1 + 1], ldz); } else { dlae2_(&d__[l - 1], &e[l - 1], &d__[l], &rt1, &rt2); } d__[l - 1] = rt1; d__[l] = rt2; e[l - 1] = 0.; l += -2; if (l >= lend) { goto L90; } goto L140; } if (jtot == nmaxit) { goto L140; } ++jtot; /* Form shift. */ g = (d__[l - 1] - p) / (e[l - 1] * 2.); r__ = dlapy2_(&g, &c_b1034); g = d__[m] - p + e[l - 1] / (g + d_sign(&r__, &g)); s = 1.; c__ = 1.; p = 0.; /* Inner loop */ lm1 = l - 1; i__1 = lm1; for (i__ = m; i__ <= i__1; ++i__) { f = s * e[i__]; b = c__ * e[i__]; dlartg_(&g, &f, &c__, &s, &r__); if (i__ != m) { e[i__ - 1] = r__; } g = d__[i__] - p; r__ = (d__[i__ + 1] - g) * s + c__ * 2. * b; p = s * r__; d__[i__] = g + p; g = c__ * r__ - b; /* If eigenvectors are desired, then save rotations. */ if (icompz > 0) { work[i__] = c__; work[*n - 1 + i__] = s; } /* L120: */ } /* If eigenvectors are desired, then apply saved rotations. */ if (icompz > 0) { mm = l - m + 1; zlasr_("R", "V", "F", n, &mm, &work[m], &work[*n - 1 + m], &z__[m * z_dim1 + 1], ldz); } d__[l] -= p; e[lm1] = g; goto L90; /* Eigenvalue found. */ L130: d__[l] = p; --l; if (l >= lend) { goto L90; } goto L140; } /* Undo scaling if necessary */ L140: if (iscale == 1) { i__1 = lendsv - lsv + 1; dlascl_("G", &c__0, &c__0, &ssfmax, &anorm, &i__1, &c__1, &d__[lsv], n, info); i__1 = lendsv - lsv; dlascl_("G", &c__0, &c__0, &ssfmax, &anorm, &i__1, &c__1, &e[lsv], n, info); } else if (iscale == 2) { i__1 = lendsv - lsv + 1; dlascl_("G", &c__0, &c__0, &ssfmin, &anorm, &i__1, &c__1, &d__[lsv], n, info); i__1 = lendsv - lsv; dlascl_("G", &c__0, &c__0, &ssfmin, &anorm, &i__1, &c__1, &e[lsv], n, info); } /* Check for no convergence to an eigenvalue after a total of N*MAXIT iterations. */ if (jtot == nmaxit) { i__1 = *n - 1; for (i__ = 1; i__ <= i__1; ++i__) { if (e[i__] != 0.) { ++(*info); } /* L150: */ } return 0; } goto L10; /* Order eigenvalues and eigenvectors. */ L160: if (icompz == 0) { /* Use Quick Sort */ dlasrt_("I", n, &d__[1], info); } else { /* Use Selection Sort to minimize swaps of eigenvectors */ i__1 = *n; for (ii = 2; ii <= i__1; ++ii) { i__ = ii - 1; k = i__; p = d__[i__]; i__2 = *n; for (j = ii; j <= i__2; ++j) { if (d__[j] < p) { k = j; p = d__[j]; } /* L170: */ } if (k != i__) { d__[k] = d__[i__]; d__[i__] = p; zswap_(n, &z__[i__ * z_dim1 + 1], &c__1, &z__[k * z_dim1 + 1], &c__1); } /* L180: */ } } return 0; /* End of ZSTEQR */ } /* zsteqr_ */ /* Subroutine */ int ztrevc_(char *side, char *howmny, logical *select, integer *n, doublecomplex *t, integer *ldt, doublecomplex *vl, integer *ldvl, doublecomplex *vr, integer *ldvr, integer *mm, integer *m, doublecomplex *work, doublereal *rwork, integer *info) { /* System generated locals */ integer t_dim1, t_offset, vl_dim1, vl_offset, vr_dim1, vr_offset, i__1, i__2, i__3, i__4, i__5; doublereal d__1, d__2, d__3; doublecomplex z__1, z__2; /* Builtin functions */ double d_imag(doublecomplex *); void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j, k, ii, ki, is; static doublereal ulp; static logical allv; static doublereal unfl, ovfl, smin; static logical over; static doublereal scale; extern logical lsame_(char *, char *); static doublereal remax; static logical leftv, bothv; extern /* Subroutine */ int zgemv_(char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static logical somev; extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), dlabad_(doublereal *, doublereal *); extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_( integer *, doublereal *, doublecomplex *, integer *); extern integer izamax_(integer *, doublecomplex *, integer *); static logical rightv; extern doublereal dzasum_(integer *, doublecomplex *, integer *); static doublereal smlnum; extern /* Subroutine */ int zlatrs_(char *, char *, char *, char *, integer *, doublecomplex *, integer *, doublecomplex *, doublereal *, doublereal *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZTREVC computes some or all of the right and/or left eigenvectors of a complex upper triangular matrix T. Matrices of this type are produced by the Schur factorization of a complex general matrix: A = Q*T*Q**H, as computed by ZHSEQR. The right eigenvector x and the left eigenvector y of T corresponding to an eigenvalue w are defined by: T*x = w*x, (y**H)*T = w*(y**H) where y**H denotes the conjugate transpose of the vector y. The eigenvalues are not input to this routine, but are read directly from the diagonal of T. This routine returns the matrices X and/or Y of right and left eigenvectors of T, or the products Q*X and/or Q*Y, where Q is an input matrix. If Q is the unitary factor that reduces a matrix A to Schur form T, then Q*X and Q*Y are the matrices of right and left eigenvectors of A. Arguments ========= SIDE (input) CHARACTER*1 = 'R': compute right eigenvectors only; = 'L': compute left eigenvectors only; = 'B': compute both right and left eigenvectors. HOWMNY (input) CHARACTER*1 = 'A': compute all right and/or left eigenvectors; = 'B': compute all right and/or left eigenvectors, backtransformed using the matrices supplied in VR and/or VL; = 'S': compute selected right and/or left eigenvectors, as indicated by the logical array SELECT. SELECT (input) LOGICAL array, dimension (N) If HOWMNY = 'S', SELECT specifies the eigenvectors to be computed. The eigenvector corresponding to the j-th eigenvalue is computed if SELECT(j) = .TRUE.. Not referenced if HOWMNY = 'A' or 'B'. N (input) INTEGER The order of the matrix T. N >= 0. T (input/output) COMPLEX*16 array, dimension (LDT,N) The upper triangular matrix T. T is modified, but restored on exit. LDT (input) INTEGER The leading dimension of the array T. LDT >= max(1,N). VL (input/output) COMPLEX*16 array, dimension (LDVL,MM) On entry, if SIDE = 'L' or 'B' and HOWMNY = 'B', VL must contain an N-by-N matrix Q (usually the unitary matrix Q of Schur vectors returned by ZHSEQR). On exit, if SIDE = 'L' or 'B', VL contains: if HOWMNY = 'A', the matrix Y of left eigenvectors of T; if HOWMNY = 'B', the matrix Q*Y; if HOWMNY = 'S', the left eigenvectors of T specified by SELECT, stored consecutively in the columns of VL, in the same order as their eigenvalues. Not referenced if SIDE = 'R'. LDVL (input) INTEGER The leading dimension of the array VL. LDVL >= 1, and if SIDE = 'L' or 'B', LDVL >= N. VR (input/output) COMPLEX*16 array, dimension (LDVR,MM) On entry, if SIDE = 'R' or 'B' and HOWMNY = 'B', VR must contain an N-by-N matrix Q (usually the unitary matrix Q of Schur vectors returned by ZHSEQR). On exit, if SIDE = 'R' or 'B', VR contains: if HOWMNY = 'A', the matrix X of right eigenvectors of T; if HOWMNY = 'B', the matrix Q*X; if HOWMNY = 'S', the right eigenvectors of T specified by SELECT, stored consecutively in the columns of VR, in the same order as their eigenvalues. Not referenced if SIDE = 'L'. LDVR (input) INTEGER The leading dimension of the array VR. LDVR >= 1, and if SIDE = 'R' or 'B'; LDVR >= N. MM (input) INTEGER The number of columns in the arrays VL and/or VR. MM >= M. M (output) INTEGER The number of columns in the arrays VL and/or VR actually used to store the eigenvectors. If HOWMNY = 'A' or 'B', M is set to N. Each selected eigenvector occupies one column. WORK (workspace) COMPLEX*16 array, dimension (2*N) RWORK (workspace) DOUBLE PRECISION array, dimension (N) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== The algorithm used in this program is basically backward (forward) substitution, with scaling to make the the code robust against possible overflow. Each eigenvector is normalized so that the element of largest magnitude has magnitude 1; here the magnitude of a complex number (x,y) is taken to be |x| + |y|. ===================================================================== Decode and test the input parameters */ /* Parameter adjustments */ --select; t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; vl_dim1 = *ldvl; vl_offset = 1 + vl_dim1; vl -= vl_offset; vr_dim1 = *ldvr; vr_offset = 1 + vr_dim1; vr -= vr_offset; --work; --rwork; /* Function Body */ bothv = lsame_(side, "B"); rightv = lsame_(side, "R") || bothv; leftv = lsame_(side, "L") || bothv; allv = lsame_(howmny, "A"); over = lsame_(howmny, "B"); somev = lsame_(howmny, "S"); /* Set M to the number of columns required to store the selected eigenvectors. */ if (somev) { *m = 0; i__1 = *n; for (j = 1; j <= i__1; ++j) { if (select[j]) { ++(*m); } /* L10: */ } } else { *m = *n; } *info = 0; if (! rightv && ! leftv) { *info = -1; } else if (! allv && ! over && ! somev) { *info = -2; } else if (*n < 0) { *info = -4; } else if (*ldt < max(1,*n)) { *info = -6; } else if (*ldvl < 1 || leftv && *ldvl < *n) { *info = -8; } else if (*ldvr < 1 || rightv && *ldvr < *n) { *info = -10; } else if (*mm < *m) { *info = -11; } if (*info != 0) { i__1 = -(*info); xerbla_("ZTREVC", &i__1); return 0; } /* Quick return if possible. */ if (*n == 0) { return 0; } /* Set the constants to control overflow. */ unfl = SAFEMINIMUM; ovfl = 1. / unfl; dlabad_(&unfl, &ovfl); ulp = PRECISION; smlnum = unfl * (*n / ulp); /* Store the diagonal elements of T in working array WORK. */ i__1 = *n; for (i__ = 1; i__ <= i__1; ++i__) { i__2 = i__ + *n; i__3 = i__ + i__ * t_dim1; work[i__2].r = t[i__3].r, work[i__2].i = t[i__3].i; /* L20: */ } /* Compute 1-norm of each column of strictly upper triangular part of T to control overflow in triangular solver. */ rwork[1] = 0.; i__1 = *n; for (j = 2; j <= i__1; ++j) { i__2 = j - 1; rwork[j] = dzasum_(&i__2, &t[j * t_dim1 + 1], &c__1); /* L30: */ } if (rightv) { /* Compute right eigenvectors. */ is = *m; for (ki = *n; ki >= 1; --ki) { if (somev) { if (! select[ki]) { goto L80; } } /* Computing MAX */ i__1 = ki + ki * t_dim1; d__3 = ulp * ((d__1 = t[i__1].r, abs(d__1)) + (d__2 = d_imag(&t[ ki + ki * t_dim1]), abs(d__2))); smin = max(d__3,smlnum); work[1].r = 1., work[1].i = 0.; /* Form right-hand side. */ i__1 = ki - 1; for (k = 1; k <= i__1; ++k) { i__2 = k; i__3 = k + ki * t_dim1; z__1.r = -t[i__3].r, z__1.i = -t[i__3].i; work[i__2].r = z__1.r, work[i__2].i = z__1.i; /* L40: */ } /* Solve the triangular system: (T(1:KI-1,1:KI-1) - T(KI,KI))*X = SCALE*WORK. */ i__1 = ki - 1; for (k = 1; k <= i__1; ++k) { i__2 = k + k * t_dim1; i__3 = k + k * t_dim1; i__4 = ki + ki * t_dim1; z__1.r = t[i__3].r - t[i__4].r, z__1.i = t[i__3].i - t[i__4] .i; t[i__2].r = z__1.r, t[i__2].i = z__1.i; i__2 = k + k * t_dim1; if ((d__1 = t[i__2].r, abs(d__1)) + (d__2 = d_imag(&t[k + k * t_dim1]), abs(d__2)) < smin) { i__3 = k + k * t_dim1; t[i__3].r = smin, t[i__3].i = 0.; } /* L50: */ } if (ki > 1) { i__1 = ki - 1; zlatrs_("Upper", "No transpose", "Non-unit", "Y", &i__1, &t[ t_offset], ldt, &work[1], &scale, &rwork[1], info); i__1 = ki; work[i__1].r = scale, work[i__1].i = 0.; } /* Copy the vector x or Q*x to VR and normalize. */ if (! over) { zcopy_(&ki, &work[1], &c__1, &vr[is * vr_dim1 + 1], &c__1); ii = izamax_(&ki, &vr[is * vr_dim1 + 1], &c__1); i__1 = ii + is * vr_dim1; remax = 1. / ((d__1 = vr[i__1].r, abs(d__1)) + (d__2 = d_imag( &vr[ii + is * vr_dim1]), abs(d__2))); zdscal_(&ki, &remax, &vr[is * vr_dim1 + 1], &c__1); i__1 = *n; for (k = ki + 1; k <= i__1; ++k) { i__2 = k + is * vr_dim1; vr[i__2].r = 0., vr[i__2].i = 0.; /* L60: */ } } else { if (ki > 1) { i__1 = ki - 1; z__1.r = scale, z__1.i = 0.; zgemv_("N", n, &i__1, &c_b57, &vr[vr_offset], ldvr, &work[ 1], &c__1, &z__1, &vr[ki * vr_dim1 + 1], &c__1); } ii = izamax_(n, &vr[ki * vr_dim1 + 1], &c__1); i__1 = ii + ki * vr_dim1; remax = 1. / ((d__1 = vr[i__1].r, abs(d__1)) + (d__2 = d_imag( &vr[ii + ki * vr_dim1]), abs(d__2))); zdscal_(n, &remax, &vr[ki * vr_dim1 + 1], &c__1); } /* Set back the original diagonal elements of T. */ i__1 = ki - 1; for (k = 1; k <= i__1; ++k) { i__2 = k + k * t_dim1; i__3 = k + *n; t[i__2].r = work[i__3].r, t[i__2].i = work[i__3].i; /* L70: */ } --is; L80: ; } } if (leftv) { /* Compute left eigenvectors. */ is = 1; i__1 = *n; for (ki = 1; ki <= i__1; ++ki) { if (somev) { if (! select[ki]) { goto L130; } } /* Computing MAX */ i__2 = ki + ki * t_dim1; d__3 = ulp * ((d__1 = t[i__2].r, abs(d__1)) + (d__2 = d_imag(&t[ ki + ki * t_dim1]), abs(d__2))); smin = max(d__3,smlnum); i__2 = *n; work[i__2].r = 1., work[i__2].i = 0.; /* Form right-hand side. */ i__2 = *n; for (k = ki + 1; k <= i__2; ++k) { i__3 = k; d_cnjg(&z__2, &t[ki + k * t_dim1]); z__1.r = -z__2.r, z__1.i = -z__2.i; work[i__3].r = z__1.r, work[i__3].i = z__1.i; /* L90: */ } /* Solve the triangular system: (T(KI+1:N,KI+1:N) - T(KI,KI))'*X = SCALE*WORK. */ i__2 = *n; for (k = ki + 1; k <= i__2; ++k) { i__3 = k + k * t_dim1; i__4 = k + k * t_dim1; i__5 = ki + ki * t_dim1; z__1.r = t[i__4].r - t[i__5].r, z__1.i = t[i__4].i - t[i__5] .i; t[i__3].r = z__1.r, t[i__3].i = z__1.i; i__3 = k + k * t_dim1; if ((d__1 = t[i__3].r, abs(d__1)) + (d__2 = d_imag(&t[k + k * t_dim1]), abs(d__2)) < smin) { i__4 = k + k * t_dim1; t[i__4].r = smin, t[i__4].i = 0.; } /* L100: */ } if (ki < *n) { i__2 = *n - ki; zlatrs_("Upper", "Conjugate transpose", "Non-unit", "Y", & i__2, &t[ki + 1 + (ki + 1) * t_dim1], ldt, &work[ki + 1], &scale, &rwork[1], info); i__2 = ki; work[i__2].r = scale, work[i__2].i = 0.; } /* Copy the vector x or Q*x to VL and normalize. */ if (! over) { i__2 = *n - ki + 1; zcopy_(&i__2, &work[ki], &c__1, &vl[ki + is * vl_dim1], &c__1) ; i__2 = *n - ki + 1; ii = izamax_(&i__2, &vl[ki + is * vl_dim1], &c__1) + ki - 1; i__2 = ii + is * vl_dim1; remax = 1. / ((d__1 = vl[i__2].r, abs(d__1)) + (d__2 = d_imag( &vl[ii + is * vl_dim1]), abs(d__2))); i__2 = *n - ki + 1; zdscal_(&i__2, &remax, &vl[ki + is * vl_dim1], &c__1); i__2 = ki - 1; for (k = 1; k <= i__2; ++k) { i__3 = k + is * vl_dim1; vl[i__3].r = 0., vl[i__3].i = 0.; /* L110: */ } } else { if (ki < *n) { i__2 = *n - ki; z__1.r = scale, z__1.i = 0.; zgemv_("N", n, &i__2, &c_b57, &vl[(ki + 1) * vl_dim1 + 1], ldvl, &work[ki + 1], &c__1, &z__1, &vl[ki * vl_dim1 + 1], &c__1); } ii = izamax_(n, &vl[ki * vl_dim1 + 1], &c__1); i__2 = ii + ki * vl_dim1; remax = 1. / ((d__1 = vl[i__2].r, abs(d__1)) + (d__2 = d_imag( &vl[ii + ki * vl_dim1]), abs(d__2))); zdscal_(n, &remax, &vl[ki * vl_dim1 + 1], &c__1); } /* Set back the original diagonal elements of T. */ i__2 = *n; for (k = ki + 1; k <= i__2; ++k) { i__3 = k + k * t_dim1; i__4 = k + *n; t[i__3].r = work[i__4].r, t[i__3].i = work[i__4].i; /* L120: */ } ++is; L130: ; } } return 0; /* End of ZTREVC */ } /* ztrevc_ */ /* Subroutine */ int ztrexc_(char *compq, integer *n, doublecomplex *t, integer *ldt, doublecomplex *q, integer *ldq, integer *ifst, integer * ilst, integer *info) { /* System generated locals */ integer q_dim1, q_offset, t_dim1, t_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer k, m1, m2, m3; static doublereal cs; static doublecomplex t11, t22, sn, temp; extern /* Subroutine */ int zrot_(integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublereal *, doublecomplex *); extern logical lsame_(char *, char *); static logical wantq; extern /* Subroutine */ int xerbla_(char *, integer *), zlartg_( doublecomplex *, doublecomplex *, doublereal *, doublecomplex *, doublecomplex *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZTREXC reorders the Schur factorization of a complex matrix A = Q*T*Q**H, so that the diagonal element of T with row index IFST is moved to row ILST. The Schur form T is reordered by a unitary similarity transformation Z**H*T*Z, and optionally the matrix Q of Schur vectors is updated by postmultplying it with Z. Arguments ========= COMPQ (input) CHARACTER*1 = 'V': update the matrix Q of Schur vectors; = 'N': do not update Q. N (input) INTEGER The order of the matrix T. N >= 0. T (input/output) COMPLEX*16 array, dimension (LDT,N) On entry, the upper triangular matrix T. On exit, the reordered upper triangular matrix. LDT (input) INTEGER The leading dimension of the array T. LDT >= max(1,N). Q (input/output) COMPLEX*16 array, dimension (LDQ,N) On entry, if COMPQ = 'V', the matrix Q of Schur vectors. On exit, if COMPQ = 'V', Q has been postmultiplied by the unitary transformation matrix Z which reorders T. If COMPQ = 'N', Q is not referenced. LDQ (input) INTEGER The leading dimension of the array Q. LDQ >= max(1,N). IFST (input) INTEGER ILST (input) INTEGER Specify the reordering of the diagonal elements of T: The element with row index IFST is moved to row ILST by a sequence of transpositions between adjacent elements. 1 <= IFST <= N; 1 <= ILST <= N. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Decode and test the input parameters. */ /* Parameter adjustments */ t_dim1 = *ldt; t_offset = 1 + t_dim1; t -= t_offset; q_dim1 = *ldq; q_offset = 1 + q_dim1; q -= q_offset; /* Function Body */ *info = 0; wantq = lsame_(compq, "V"); if (! lsame_(compq, "N") && ! wantq) { *info = -1; } else if (*n < 0) { *info = -2; } else if (*ldt < max(1,*n)) { *info = -4; } else if (*ldq < 1 || wantq && *ldq < max(1,*n)) { *info = -6; } else if (*ifst < 1 || *ifst > *n) { *info = -7; } else if (*ilst < 1 || *ilst > *n) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZTREXC", &i__1); return 0; } /* Quick return if possible */ if (*n == 1 || *ifst == *ilst) { return 0; } if (*ifst < *ilst) { /* Move the IFST-th diagonal element forward down the diagonal. */ m1 = 0; m2 = -1; m3 = 1; } else { /* Move the IFST-th diagonal element backward up the diagonal. */ m1 = -1; m2 = 0; m3 = -1; } i__1 = *ilst + m2; i__2 = m3; for (k = *ifst + m1; i__2 < 0 ? k >= i__1 : k <= i__1; k += i__2) { /* Interchange the k-th and (k+1)-th diagonal elements. */ i__3 = k + k * t_dim1; t11.r = t[i__3].r, t11.i = t[i__3].i; i__3 = k + 1 + (k + 1) * t_dim1; t22.r = t[i__3].r, t22.i = t[i__3].i; /* Determine the transformation to perform the interchange. */ z__1.r = t22.r - t11.r, z__1.i = t22.i - t11.i; zlartg_(&t[k + (k + 1) * t_dim1], &z__1, &cs, &sn, &temp); /* Apply transformation to the matrix T. */ if (k + 2 <= *n) { i__3 = *n - k - 1; zrot_(&i__3, &t[k + (k + 2) * t_dim1], ldt, &t[k + 1 + (k + 2) * t_dim1], ldt, &cs, &sn); } i__3 = k - 1; d_cnjg(&z__1, &sn); zrot_(&i__3, &t[k * t_dim1 + 1], &c__1, &t[(k + 1) * t_dim1 + 1], & c__1, &cs, &z__1); i__3 = k + k * t_dim1; t[i__3].r = t22.r, t[i__3].i = t22.i; i__3 = k + 1 + (k + 1) * t_dim1; t[i__3].r = t11.r, t[i__3].i = t11.i; if (wantq) { /* Accumulate transformation in the matrix Q. */ d_cnjg(&z__1, &sn); zrot_(n, &q[k * q_dim1 + 1], &c__1, &q[(k + 1) * q_dim1 + 1], & c__1, &cs, &z__1); } /* L10: */ } return 0; /* End of ZTREXC */ } /* ztrexc_ */ /* Subroutine */ int ztrti2_(char *uplo, char *diag, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2; doublecomplex z__1; /* Builtin functions */ void z_div(doublecomplex *, doublecomplex *, doublecomplex *); /* Local variables */ static integer j; static doublecomplex ajj; extern logical lsame_(char *, char *); extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *); static logical upper; extern /* Subroutine */ int ztrmv_(char *, char *, char *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); static logical nounit; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZTRTI2 computes the inverse of a complex upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm. Arguments ========= UPLO (input) CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG (input) CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the triangular matrix A. If UPLO = 'U', the leading n by n upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. On exit, the (triangular) inverse of the original matrix, in the same storage format. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); nounit = lsame_(diag, "N"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (! nounit && ! lsame_(diag, "U")) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } if (*info != 0) { i__1 = -(*info); xerbla_("ZTRTI2", &i__1); return 0; } if (upper) { /* Compute inverse of upper triangular matrix. */ i__1 = *n; for (j = 1; j <= i__1; ++j) { if (nounit) { i__2 = j + j * a_dim1; z_div(&z__1, &c_b57, &a[j + j * a_dim1]); a[i__2].r = z__1.r, a[i__2].i = z__1.i; i__2 = j + j * a_dim1; z__1.r = -a[i__2].r, z__1.i = -a[i__2].i; ajj.r = z__1.r, ajj.i = z__1.i; } else { z__1.r = -1., z__1.i = -0.; ajj.r = z__1.r, ajj.i = z__1.i; } /* Compute elements 1:j-1 of j-th column. */ i__2 = j - 1; ztrmv_("Upper", "No transpose", diag, &i__2, &a[a_offset], lda, & a[j * a_dim1 + 1], &c__1); i__2 = j - 1; zscal_(&i__2, &ajj, &a[j * a_dim1 + 1], &c__1); /* L10: */ } } else { /* Compute inverse of lower triangular matrix. */ for (j = *n; j >= 1; --j) { if (nounit) { i__1 = j + j * a_dim1; z_div(&z__1, &c_b57, &a[j + j * a_dim1]); a[i__1].r = z__1.r, a[i__1].i = z__1.i; i__1 = j + j * a_dim1; z__1.r = -a[i__1].r, z__1.i = -a[i__1].i; ajj.r = z__1.r, ajj.i = z__1.i; } else { z__1.r = -1., z__1.i = -0.; ajj.r = z__1.r, ajj.i = z__1.i; } if (j < *n) { /* Compute elements j+1:n of j-th column. */ i__1 = *n - j; ztrmv_("Lower", "No transpose", diag, &i__1, &a[j + 1 + (j + 1) * a_dim1], lda, &a[j + 1 + j * a_dim1], &c__1); i__1 = *n - j; zscal_(&i__1, &ajj, &a[j + 1 + j * a_dim1], &c__1); } /* L20: */ } } return 0; /* End of ZTRTI2 */ } /* ztrti2_ */ /* Subroutine */ int ztrtri_(char *uplo, char *diag, integer *n, doublecomplex *a, integer *lda, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, i__1, i__2, i__3[2], i__4, i__5; doublecomplex z__1; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer j, jb, nb, nn; extern logical lsame_(char *, char *); static logical upper; extern /* Subroutine */ int ztrmm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), ztrsm_(char *, char *, char *, char *, integer *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), ztrti2_(char *, char * , integer *, doublecomplex *, integer *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static logical nounit; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZTRTRI computes the inverse of a complex upper or lower triangular matrix A. This is the Level 3 BLAS version of the algorithm. Arguments ========= UPLO (input) CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular. DIAG (input) CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is unit triangular. N (input) INTEGER The order of the matrix A. N >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the triangular matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. On exit, the (triangular) inverse of the original matrix, in the same storage format. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, A(i,i) is exactly zero. The triangular matrix is singular and its inverse can not be computed. ===================================================================== Test the input parameters. */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; /* Function Body */ *info = 0; upper = lsame_(uplo, "U"); nounit = lsame_(diag, "N"); if (! upper && ! lsame_(uplo, "L")) { *info = -1; } else if (! nounit && ! lsame_(diag, "U")) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } if (*info != 0) { i__1 = -(*info); xerbla_("ZTRTRI", &i__1); return 0; } /* Quick return if possible */ if (*n == 0) { return 0; } /* Check for singularity if non-unit. */ if (nounit) { i__1 = *n; for (*info = 1; *info <= i__1; ++(*info)) { i__2 = *info + *info * a_dim1; if (a[i__2].r == 0. && a[i__2].i == 0.) { return 0; } /* L10: */ } *info = 0; } /* Determine the block size for this environment. Writing concatenation */ i__3[0] = 1, a__1[0] = uplo; i__3[1] = 1, a__1[1] = diag; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); nb = ilaenv_(&c__1, "ZTRTRI", ch__1, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, ( ftnlen)2); if (nb <= 1 || nb >= *n) { /* Use unblocked code */ ztrti2_(uplo, diag, n, &a[a_offset], lda, info); } else { /* Use blocked code */ if (upper) { /* Compute inverse of upper triangular matrix */ i__1 = *n; i__2 = nb; for (j = 1; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { /* Computing MIN */ i__4 = nb, i__5 = *n - j + 1; jb = min(i__4,i__5); /* Compute rows 1:j-1 of current block column */ i__4 = j - 1; ztrmm_("Left", "Upper", "No transpose", diag, &i__4, &jb, & c_b57, &a[a_offset], lda, &a[j * a_dim1 + 1], lda); i__4 = j - 1; z__1.r = -1., z__1.i = -0.; ztrsm_("Right", "Upper", "No transpose", diag, &i__4, &jb, & z__1, &a[j + j * a_dim1], lda, &a[j * a_dim1 + 1], lda); /* Compute inverse of current diagonal block */ ztrti2_("Upper", diag, &jb, &a[j + j * a_dim1], lda, info); /* L20: */ } } else { /* Compute inverse of lower triangular matrix */ nn = (*n - 1) / nb * nb + 1; i__2 = -nb; for (j = nn; i__2 < 0 ? j >= 1 : j <= 1; j += i__2) { /* Computing MIN */ i__1 = nb, i__4 = *n - j + 1; jb = min(i__1,i__4); if (j + jb <= *n) { /* Compute rows j+jb:n of current block column */ i__1 = *n - j - jb + 1; ztrmm_("Left", "Lower", "No transpose", diag, &i__1, &jb, &c_b57, &a[j + jb + (j + jb) * a_dim1], lda, &a[j + jb + j * a_dim1], lda); i__1 = *n - j - jb + 1; z__1.r = -1., z__1.i = -0.; ztrsm_("Right", "Lower", "No transpose", diag, &i__1, &jb, &z__1, &a[j + j * a_dim1], lda, &a[j + jb + j * a_dim1], lda); } /* Compute inverse of current diagonal block */ ztrti2_("Lower", diag, &jb, &a[j + j * a_dim1], lda, info); /* L30: */ } } } return 0; /* End of ZTRTRI */ } /* ztrtri_ */ /* Subroutine */ int zung2r_(integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublecomplex z__1; /* Local variables */ static integer i__, j, l; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *), zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNG2R generates an m by n complex matrix Q with orthonormal columns, which is defined as the first n columns of a product of k elementary reflectors of order m Q = H(1) H(2) . . . H(k) as returned by ZGEQRF. Arguments ========= M (input) INTEGER The number of rows of the matrix Q. M >= 0. N (input) INTEGER The number of columns of the matrix Q. M >= N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQRF in the first k columns of its array argument A. On exit, the m by n matrix Q. LDA (input) INTEGER The first dimension of the array A. LDA >= max(1,M). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQRF. WORK (workspace) COMPLEX*16 array, dimension (N) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < 0 || *n > *m) { *info = -2; } else if (*k < 0 || *k > *n) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNG2R", &i__1); return 0; } /* Quick return if possible */ if (*n <= 0) { return 0; } /* Initialise columns k+1:n to columns of the unit matrix */ i__1 = *n; for (j = *k + 1; j <= i__1; ++j) { i__2 = *m; for (l = 1; l <= i__2; ++l) { i__3 = l + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L10: */ } i__2 = j + j * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* L20: */ } for (i__ = *k; i__ >= 1; --i__) { /* Apply H(i) to A(i:m,i:n) from the left */ if (i__ < *n) { i__1 = i__ + i__ * a_dim1; a[i__1].r = 1., a[i__1].i = 0.; i__1 = *m - i__ + 1; i__2 = *n - i__; zlarf_("Left", &i__1, &i__2, &a[i__ + i__ * a_dim1], &c__1, &tau[ i__], &a[i__ + (i__ + 1) * a_dim1], lda, &work[1]); } if (i__ < *m) { i__1 = *m - i__; i__2 = i__; z__1.r = -tau[i__2].r, z__1.i = -tau[i__2].i; zscal_(&i__1, &z__1, &a[i__ + 1 + i__ * a_dim1], &c__1); } i__1 = i__ + i__ * a_dim1; i__2 = i__; z__1.r = 1. - tau[i__2].r, z__1.i = 0. - tau[i__2].i; a[i__1].r = z__1.r, a[i__1].i = z__1.i; /* Set A(1:i-1,i) to zero */ i__1 = i__ - 1; for (l = 1; l <= i__1; ++l) { i__2 = l + i__ * a_dim1; a[i__2].r = 0., a[i__2].i = 0.; /* L30: */ } /* L40: */ } return 0; /* End of ZUNG2R */ } /* zung2r_ */ /* Subroutine */ int zungbr_(char *vect, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; /* Local variables */ static integer i__, j, nb, mn; extern logical lsame_(char *, char *); static integer iinfo; static logical wantq; extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static integer lwkopt; static logical lquery; extern /* Subroutine */ int zunglq_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *), zungqr_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNGBR generates one of the complex unitary matrices Q or P**H determined by ZGEBRD when reducing a complex matrix A to bidiagonal form: A = Q * B * P**H. Q and P**H are defined as products of elementary reflectors H(i) or G(i) respectively. If VECT = 'Q', A is assumed to have been an M-by-K matrix, and Q is of order M: if m >= k, Q = H(1) H(2) . . . H(k) and ZUNGBR returns the first n columns of Q, where m >= n >= k; if m < k, Q = H(1) H(2) . . . H(m-1) and ZUNGBR returns Q as an M-by-M matrix. If VECT = 'P', A is assumed to have been a K-by-N matrix, and P**H is of order N: if k < n, P**H = G(k) . . . G(2) G(1) and ZUNGBR returns the first m rows of P**H, where n >= m >= k; if k >= n, P**H = G(n-1) . . . G(2) G(1) and ZUNGBR returns P**H as an N-by-N matrix. Arguments ========= VECT (input) CHARACTER*1 Specifies whether the matrix Q or the matrix P**H is required, as defined in the transformation applied by ZGEBRD: = 'Q': generate Q; = 'P': generate P**H. M (input) INTEGER The number of rows of the matrix Q or P**H to be returned. M >= 0. N (input) INTEGER The number of columns of the matrix Q or P**H to be returned. N >= 0. If VECT = 'Q', M >= N >= min(M,K); if VECT = 'P', N >= M >= min(N,K). K (input) INTEGER If VECT = 'Q', the number of columns in the original M-by-K matrix reduced by ZGEBRD. If VECT = 'P', the number of rows in the original K-by-N matrix reduced by ZGEBRD. K >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the vectors which define the elementary reflectors, as returned by ZGEBRD. On exit, the M-by-N matrix Q or P**H. LDA (input) INTEGER The leading dimension of the array A. LDA >= M. TAU (input) COMPLEX*16 array, dimension (min(M,K)) if VECT = 'Q' (min(N,K)) if VECT = 'P' TAU(i) must contain the scalar factor of the elementary reflector H(i) or G(i), which determines Q or P**H, as returned by ZGEBRD in its array argument TAUQ or TAUP. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= max(1,min(M,N)). For optimum performance LWORK >= min(M,N)*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; wantq = lsame_(vect, "Q"); mn = min(*m,*n); lquery = *lwork == -1; if (! wantq && ! lsame_(vect, "P")) { *info = -1; } else if (*m < 0) { *info = -2; } else if (*n < 0 || wantq && (*n > *m || *n < min(*m,*k)) || ! wantq && ( *m > *n || *m < min(*n,*k))) { *info = -3; } else if (*k < 0) { *info = -4; } else if (*lda < max(1,*m)) { *info = -6; } else if (*lwork < max(1,mn) && ! lquery) { *info = -9; } if (*info == 0) { if (wantq) { nb = ilaenv_(&c__1, "ZUNGQR", " ", m, n, k, &c_n1, (ftnlen)6, ( ftnlen)1); } else { nb = ilaenv_(&c__1, "ZUNGLQ", " ", m, n, k, &c_n1, (ftnlen)6, ( ftnlen)1); } lwkopt = max(1,mn) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNGBR", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { work[1].r = 1., work[1].i = 0.; return 0; } if (wantq) { /* Form Q, determined by a call to ZGEBRD to reduce an m-by-k matrix */ if (*m >= *k) { /* If m >= k, assume m >= n >= k */ zungqr_(m, n, k, &a[a_offset], lda, &tau[1], &work[1], lwork, & iinfo); } else { /* If m < k, assume m = n Shift the vectors which define the elementary reflectors one column to the right, and set the first row and column of Q to those of the unit matrix */ for (j = *m; j >= 2; --j) { i__1 = j * a_dim1 + 1; a[i__1].r = 0., a[i__1].i = 0.; i__1 = *m; for (i__ = j + 1; i__ <= i__1; ++i__) { i__2 = i__ + j * a_dim1; i__3 = i__ + (j - 1) * a_dim1; a[i__2].r = a[i__3].r, a[i__2].i = a[i__3].i; /* L10: */ } /* L20: */ } i__1 = a_dim1 + 1; a[i__1].r = 1., a[i__1].i = 0.; i__1 = *m; for (i__ = 2; i__ <= i__1; ++i__) { i__2 = i__ + a_dim1; a[i__2].r = 0., a[i__2].i = 0.; /* L30: */ } if (*m > 1) { /* Form Q(2:m,2:m) */ i__1 = *m - 1; i__2 = *m - 1; i__3 = *m - 1; zungqr_(&i__1, &i__2, &i__3, &a[(a_dim1 << 1) + 2], lda, &tau[ 1], &work[1], lwork, &iinfo); } } } else { /* Form P', determined by a call to ZGEBRD to reduce a k-by-n matrix */ if (*k < *n) { /* If k < n, assume k <= m <= n */ zunglq_(m, n, k, &a[a_offset], lda, &tau[1], &work[1], lwork, & iinfo); } else { /* If k >= n, assume m = n Shift the vectors which define the elementary reflectors one row downward, and set the first row and column of P' to those of the unit matrix */ i__1 = a_dim1 + 1; a[i__1].r = 1., a[i__1].i = 0.; i__1 = *n; for (i__ = 2; i__ <= i__1; ++i__) { i__2 = i__ + a_dim1; a[i__2].r = 0., a[i__2].i = 0.; /* L40: */ } i__1 = *n; for (j = 2; j <= i__1; ++j) { for (i__ = j - 1; i__ >= 2; --i__) { i__2 = i__ + j * a_dim1; i__3 = i__ - 1 + j * a_dim1; a[i__2].r = a[i__3].r, a[i__2].i = a[i__3].i; /* L50: */ } i__2 = j * a_dim1 + 1; a[i__2].r = 0., a[i__2].i = 0.; /* L60: */ } if (*n > 1) { /* Form P'(2:n,2:n) */ i__1 = *n - 1; i__2 = *n - 1; i__3 = *n - 1; zunglq_(&i__1, &i__2, &i__3, &a[(a_dim1 << 1) + 2], lda, &tau[ 1], &work[1], lwork, &iinfo); } } } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNGBR */ } /* zungbr_ */ /* Subroutine */ int zunghr_(integer *n, integer *ilo, integer *ihi, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, j, nb, nh, iinfo; extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static integer lwkopt; static logical lquery; extern /* Subroutine */ int zungqr_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNGHR generates a complex unitary matrix Q which is defined as the product of IHI-ILO elementary reflectors of order N, as returned by ZGEHRD: Q = H(ilo) H(ilo+1) . . . H(ihi-1). Arguments ========= N (input) INTEGER The order of the matrix Q. N >= 0. ILO (input) INTEGER IHI (input) INTEGER ILO and IHI must have the same values as in the previous call of ZGEHRD. Q is equal to the unit matrix except in the submatrix Q(ilo+1:ihi,ilo+1:ihi). 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the vectors which define the elementary reflectors, as returned by ZGEHRD. On exit, the N-by-N unitary matrix Q. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,N). TAU (input) COMPLEX*16 array, dimension (N-1) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEHRD. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= IHI-ILO. For optimum performance LWORK >= (IHI-ILO)*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; nh = *ihi - *ilo; lquery = *lwork == -1; if (*n < 0) { *info = -1; } else if (*ilo < 1 || *ilo > max(1,*n)) { *info = -2; } else if (*ihi < min(*ilo,*n) || *ihi > *n) { *info = -3; } else if (*lda < max(1,*n)) { *info = -5; } else if (*lwork < max(1,nh) && ! lquery) { *info = -8; } if (*info == 0) { nb = ilaenv_(&c__1, "ZUNGQR", " ", &nh, &nh, &nh, &c_n1, (ftnlen)6, ( ftnlen)1); lwkopt = max(1,nh) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNGHR", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*n == 0) { work[1].r = 1., work[1].i = 0.; return 0; } /* Shift the vectors which define the elementary reflectors one column to the right, and set the first ilo and the last n-ihi rows and columns to those of the unit matrix */ i__1 = *ilo + 1; for (j = *ihi; j >= i__1; --j) { i__2 = j - 1; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L10: */ } i__2 = *ihi; for (i__ = j + 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; i__4 = i__ + (j - 1) * a_dim1; a[i__3].r = a[i__4].r, a[i__3].i = a[i__4].i; /* L20: */ } i__2 = *n; for (i__ = *ihi + 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L30: */ } /* L40: */ } i__1 = *ilo; for (j = 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L50: */ } i__2 = j + j * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* L60: */ } i__1 = *n; for (j = *ihi + 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L70: */ } i__2 = j + j * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; /* L80: */ } if (nh > 0) { /* Generate Q(ilo+1:ihi,ilo+1:ihi) */ zungqr_(&nh, &nh, &nh, &a[*ilo + 1 + (*ilo + 1) * a_dim1], lda, &tau[* ilo], &work[1], lwork, &iinfo); } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNGHR */ } /* zunghr_ */ /* Subroutine */ int zungl2_(integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3; doublecomplex z__1, z__2; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, j, l; extern /* Subroutine */ int zscal_(integer *, doublecomplex *, doublecomplex *, integer *), zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *), zlacgv_(integer *, doublecomplex *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNGL2 generates an m-by-n complex matrix Q with orthonormal rows, which is defined as the first m rows of a product of k elementary reflectors of order n Q = H(k)' . . . H(2)' H(1)' as returned by ZGELQF. Arguments ========= M (input) INTEGER The number of rows of the matrix Q. M >= 0. N (input) INTEGER The number of columns of the matrix Q. N >= M. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGELQF in the first k rows of its array argument A. On exit, the m by n matrix Q. LDA (input) INTEGER The first dimension of the array A. LDA >= max(1,M). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGELQF. WORK (workspace) COMPLEX*16 array, dimension (M) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; if (*m < 0) { *info = -1; } else if (*n < *m) { *info = -2; } else if (*k < 0 || *k > *m) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNGL2", &i__1); return 0; } /* Quick return if possible */ if (*m <= 0) { return 0; } if (*k < *m) { /* Initialise rows k+1:m to rows of the unit matrix */ i__1 = *n; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (l = *k + 1; l <= i__2; ++l) { i__3 = l + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L10: */ } if (j > *k && j <= *m) { i__2 = j + j * a_dim1; a[i__2].r = 1., a[i__2].i = 0.; } /* L20: */ } } for (i__ = *k; i__ >= 1; --i__) { /* Apply H(i)' to A(i:m,i:n) from the right */ if (i__ < *n) { i__1 = *n - i__; zlacgv_(&i__1, &a[i__ + (i__ + 1) * a_dim1], lda); if (i__ < *m) { i__1 = i__ + i__ * a_dim1; a[i__1].r = 1., a[i__1].i = 0.; i__1 = *m - i__; i__2 = *n - i__ + 1; d_cnjg(&z__1, &tau[i__]); zlarf_("Right", &i__1, &i__2, &a[i__ + i__ * a_dim1], lda, & z__1, &a[i__ + 1 + i__ * a_dim1], lda, &work[1]); } i__1 = *n - i__; i__2 = i__; z__1.r = -tau[i__2].r, z__1.i = -tau[i__2].i; zscal_(&i__1, &z__1, &a[i__ + (i__ + 1) * a_dim1], lda); i__1 = *n - i__; zlacgv_(&i__1, &a[i__ + (i__ + 1) * a_dim1], lda); } i__1 = i__ + i__ * a_dim1; d_cnjg(&z__2, &tau[i__]); z__1.r = 1. - z__2.r, z__1.i = 0. - z__2.i; a[i__1].r = z__1.r, a[i__1].i = z__1.i; /* Set A(i,1:i-1) to zero */ i__1 = i__ - 1; for (l = 1; l <= i__1; ++l) { i__2 = i__ + l * a_dim1; a[i__2].r = 0., a[i__2].i = 0.; /* L30: */ } /* L40: */ } return 0; /* End of ZUNGL2 */ } /* zungl2_ */ /* Subroutine */ int zunglq_(integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, j, l, ib, nb, ki, kk, nx, iws, nbmin, iinfo; extern /* Subroutine */ int zungl2_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static logical lquery; static integer lwkopt; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNGLQ generates an M-by-N complex matrix Q with orthonormal rows, which is defined as the first M rows of a product of K elementary reflectors of order N Q = H(k)' . . . H(2)' H(1)' as returned by ZGELQF. Arguments ========= M (input) INTEGER The number of rows of the matrix Q. M >= 0. N (input) INTEGER The number of columns of the matrix Q. N >= M. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGELQF in the first k rows of its array argument A. On exit, the M-by-N matrix Q. LDA (input) INTEGER The first dimension of the array A. LDA >= max(1,M). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGELQF. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit; < 0: if INFO = -i, the i-th argument has an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; nb = ilaenv_(&c__1, "ZUNGLQ", " ", m, n, k, &c_n1, (ftnlen)6, (ftnlen)1); lwkopt = max(1,*m) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; lquery = *lwork == -1; if (*m < 0) { *info = -1; } else if (*n < *m) { *info = -2; } else if (*k < 0 || *k > *m) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } else if (*lwork < max(1,*m) && ! lquery) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNGLQ", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m <= 0) { work[1].r = 1., work[1].i = 0.; return 0; } nbmin = 2; nx = 0; iws = *m; if (nb > 1 && nb < *k) { /* Determine when to cross over from blocked to unblocked code. Computing MAX */ i__1 = 0, i__2 = ilaenv_(&c__3, "ZUNGLQ", " ", m, n, k, &c_n1, ( ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); if (nx < *k) { /* Determine if workspace is large enough for blocked code. */ ldwork = *m; iws = ldwork * nb; if (*lwork < iws) { /* Not enough workspace to use optimal NB: reduce NB and determine the minimum value of NB. */ nb = *lwork / ldwork; /* Computing MAX */ i__1 = 2, i__2 = ilaenv_(&c__2, "ZUNGLQ", " ", m, n, k, &c_n1, (ftnlen)6, (ftnlen)1); nbmin = max(i__1,i__2); } } } if (nb >= nbmin && nb < *k && nx < *k) { /* Use blocked code after the last block. The first kk rows are handled by the block method. */ ki = (*k - nx - 1) / nb * nb; /* Computing MIN */ i__1 = *k, i__2 = ki + nb; kk = min(i__1,i__2); /* Set A(kk+1:m,1:kk) to zero. */ i__1 = kk; for (j = 1; j <= i__1; ++j) { i__2 = *m; for (i__ = kk + 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L10: */ } /* L20: */ } } else { kk = 0; } /* Use unblocked code for the last or only block. */ if (kk < *m) { i__1 = *m - kk; i__2 = *n - kk; i__3 = *k - kk; zungl2_(&i__1, &i__2, &i__3, &a[kk + 1 + (kk + 1) * a_dim1], lda, & tau[kk + 1], &work[1], &iinfo); } if (kk > 0) { /* Use blocked code */ i__1 = -nb; for (i__ = ki + 1; i__1 < 0 ? i__ >= 1 : i__ <= 1; i__ += i__1) { /* Computing MIN */ i__2 = nb, i__3 = *k - i__ + 1; ib = min(i__2,i__3); if (i__ + ib <= *m) { /* Form the triangular factor of the block reflector H = H(i) H(i+1) . . . H(i+ib-1) */ i__2 = *n - i__ + 1; zlarft_("Forward", "Rowwise", &i__2, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[1], &ldwork); /* Apply H' to A(i+ib:m,i:n) from the right */ i__2 = *m - i__ - ib + 1; i__3 = *n - i__ + 1; zlarfb_("Right", "Conjugate transpose", "Forward", "Rowwise", &i__2, &i__3, &ib, &a[i__ + i__ * a_dim1], lda, &work[ 1], &ldwork, &a[i__ + ib + i__ * a_dim1], lda, &work[ ib + 1], &ldwork); } /* Apply H' to columns i:n of current block */ i__2 = *n - i__ + 1; zungl2_(&ib, &i__2, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], & work[1], &iinfo); /* Set columns 1:i-1 of current block to zero */ i__2 = i__ - 1; for (j = 1; j <= i__2; ++j) { i__3 = i__ + ib - 1; for (l = i__; l <= i__3; ++l) { i__4 = l + j * a_dim1; a[i__4].r = 0., a[i__4].i = 0.; /* L30: */ } /* L40: */ } /* L50: */ } } work[1].r = (doublereal) iws, work[1].i = 0.; return 0; /* End of ZUNGLQ */ } /* zunglq_ */ /* Subroutine */ int zungqr_(integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex * work, integer *lwork, integer *info) { /* System generated locals */ integer a_dim1, a_offset, i__1, i__2, i__3, i__4; /* Local variables */ static integer i__, j, l, ib, nb, ki, kk, nx, iws, nbmin, iinfo; extern /* Subroutine */ int zung2r_(integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNGQR generates an M-by-N complex matrix Q with orthonormal columns, which is defined as the first N columns of a product of K elementary reflectors of order M Q = H(1) H(2) . . . H(k) as returned by ZGEQRF. Arguments ========= M (input) INTEGER The number of rows of the matrix Q. M >= 0. N (input) INTEGER The number of columns of the matrix Q. M >= N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0. A (input/output) COMPLEX*16 array, dimension (LDA,N) On entry, the i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQRF in the first k columns of its array argument A. On exit, the M-by-N matrix Q. LDA (input) INTEGER The first dimension of the array A. LDA >= max(1,M). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQRF. WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= N*NB, where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; --work; /* Function Body */ *info = 0; nb = ilaenv_(&c__1, "ZUNGQR", " ", m, n, k, &c_n1, (ftnlen)6, (ftnlen)1); lwkopt = max(1,*n) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; lquery = *lwork == -1; if (*m < 0) { *info = -1; } else if (*n < 0 || *n > *m) { *info = -2; } else if (*k < 0 || *k > *n) { *info = -3; } else if (*lda < max(1,*m)) { *info = -5; } else if (*lwork < max(1,*n) && ! lquery) { *info = -8; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNGQR", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*n <= 0) { work[1].r = 1., work[1].i = 0.; return 0; } nbmin = 2; nx = 0; iws = *n; if (nb > 1 && nb < *k) { /* Determine when to cross over from blocked to unblocked code. Computing MAX */ i__1 = 0, i__2 = ilaenv_(&c__3, "ZUNGQR", " ", m, n, k, &c_n1, ( ftnlen)6, (ftnlen)1); nx = max(i__1,i__2); if (nx < *k) { /* Determine if workspace is large enough for blocked code. */ ldwork = *n; iws = ldwork * nb; if (*lwork < iws) { /* Not enough workspace to use optimal NB: reduce NB and determine the minimum value of NB. */ nb = *lwork / ldwork; /* Computing MAX */ i__1 = 2, i__2 = ilaenv_(&c__2, "ZUNGQR", " ", m, n, k, &c_n1, (ftnlen)6, (ftnlen)1); nbmin = max(i__1,i__2); } } } if (nb >= nbmin && nb < *k && nx < *k) { /* Use blocked code after the last block. The first kk columns are handled by the block method. */ ki = (*k - nx - 1) / nb * nb; /* Computing MIN */ i__1 = *k, i__2 = ki + nb; kk = min(i__1,i__2); /* Set A(1:kk,kk+1:n) to zero. */ i__1 = *n; for (j = kk + 1; j <= i__1; ++j) { i__2 = kk; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * a_dim1; a[i__3].r = 0., a[i__3].i = 0.; /* L10: */ } /* L20: */ } } else { kk = 0; } /* Use unblocked code for the last or only block. */ if (kk < *n) { i__1 = *m - kk; i__2 = *n - kk; i__3 = *k - kk; zung2r_(&i__1, &i__2, &i__3, &a[kk + 1 + (kk + 1) * a_dim1], lda, & tau[kk + 1], &work[1], &iinfo); } if (kk > 0) { /* Use blocked code */ i__1 = -nb; for (i__ = ki + 1; i__1 < 0 ? i__ >= 1 : i__ <= 1; i__ += i__1) { /* Computing MIN */ i__2 = nb, i__3 = *k - i__ + 1; ib = min(i__2,i__3); if (i__ + ib <= *n) { /* Form the triangular factor of the block reflector H = H(i) H(i+1) . . . H(i+ib-1) */ i__2 = *m - i__ + 1; zlarft_("Forward", "Columnwise", &i__2, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], &work[1], &ldwork); /* Apply H to A(i:m,i+ib:n) from the left */ i__2 = *m - i__ + 1; i__3 = *n - i__ - ib + 1; zlarfb_("Left", "No transpose", "Forward", "Columnwise", & i__2, &i__3, &ib, &a[i__ + i__ * a_dim1], lda, &work[ 1], &ldwork, &a[i__ + (i__ + ib) * a_dim1], lda, & work[ib + 1], &ldwork); } /* Apply H to rows i:m of current block */ i__2 = *m - i__ + 1; zung2r_(&i__2, &ib, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], & work[1], &iinfo); /* Set rows 1:i-1 of current block to zero */ i__2 = i__ + ib - 1; for (j = i__; j <= i__2; ++j) { i__3 = i__ - 1; for (l = 1; l <= i__3; ++l) { i__4 = l + j * a_dim1; a[i__4].r = 0., a[i__4].i = 0.; /* L30: */ } /* L40: */ } /* L50: */ } } work[1].r = (doublereal) iws, work[1].i = 0.; return 0; /* End of ZUNGQR */ } /* zungqr_ */ /* Subroutine */ int zunm2l_(char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, i1, i2, i3, mi, ni, nq; static doublecomplex aii; static logical left; static doublecomplex taui; extern logical lsame_(char *, char *); extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *); static logical notran; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNM2L overwrites the general complex m-by-n matrix C with Q * C if SIDE = 'L' and TRANS = 'N', or Q'* C if SIDE = 'L' and TRANS = 'C', or C * Q if SIDE = 'R' and TRANS = 'N', or C * Q' if SIDE = 'R' and TRANS = 'C', where Q is a complex unitary matrix defined as the product of k elementary reflectors Q = H(k) . . . H(2) H(1) as returned by ZGEQLF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q' from the Left = 'R': apply Q or Q' from the Right TRANS (input) CHARACTER*1 = 'N': apply Q (No transpose) = 'C': apply Q' (Conjugate transpose) M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. A (input) COMPLEX*16 array, dimension (LDA,K) The i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQLF in the last k columns of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. If SIDE = 'L', LDA >= max(1,M); if SIDE = 'R', LDA >= max(1,N). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQLF. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the m-by-n matrix C. On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX*16 array, dimension (N) if SIDE = 'L', (M) if SIDE = 'R' INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); /* NQ is the order of Q */ if (left) { nq = *m; } else { nq = *n; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,nq)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNM2L", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || *k == 0) { return 0; } if (left && notran || ! left && ! notran) { i1 = 1; i2 = *k; i3 = 1; } else { i1 = *k; i2 = 1; i3 = -1; } if (left) { ni = *n; } else { mi = *m; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { if (left) { /* H(i) or H(i)' is applied to C(1:m-k+i,1:n) */ mi = *m - *k + i__; } else { /* H(i) or H(i)' is applied to C(1:m,1:n-k+i) */ ni = *n - *k + i__; } /* Apply H(i) or H(i)' */ if (notran) { i__3 = i__; taui.r = tau[i__3].r, taui.i = tau[i__3].i; } else { d_cnjg(&z__1, &tau[i__]); taui.r = z__1.r, taui.i = z__1.i; } i__3 = nq - *k + i__ + i__ * a_dim1; aii.r = a[i__3].r, aii.i = a[i__3].i; i__3 = nq - *k + i__ + i__ * a_dim1; a[i__3].r = 1., a[i__3].i = 0.; zlarf_(side, &mi, &ni, &a[i__ * a_dim1 + 1], &c__1, &taui, &c__[ c_offset], ldc, &work[1]); i__3 = nq - *k + i__ + i__ * a_dim1; a[i__3].r = aii.r, a[i__3].i = aii.i; /* L10: */ } return 0; /* End of ZUNM2L */ } /* zunm2l_ */ /* Subroutine */ int zunm2r_(char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, i1, i2, i3, ic, jc, mi, ni, nq; static doublecomplex aii; static logical left; static doublecomplex taui; extern logical lsame_(char *, char *); extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *); static logical notran; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNM2R overwrites the general complex m-by-n matrix C with Q * C if SIDE = 'L' and TRANS = 'N', or Q'* C if SIDE = 'L' and TRANS = 'C', or C * Q if SIDE = 'R' and TRANS = 'N', or C * Q' if SIDE = 'R' and TRANS = 'C', where Q is a complex unitary matrix defined as the product of k elementary reflectors Q = H(1) H(2) . . . H(k) as returned by ZGEQRF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q' from the Left = 'R': apply Q or Q' from the Right TRANS (input) CHARACTER*1 = 'N': apply Q (No transpose) = 'C': apply Q' (Conjugate transpose) M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. A (input) COMPLEX*16 array, dimension (LDA,K) The i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQRF in the first k columns of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. If SIDE = 'L', LDA >= max(1,M); if SIDE = 'R', LDA >= max(1,N). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQRF. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the m-by-n matrix C. On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX*16 array, dimension (N) if SIDE = 'L', (M) if SIDE = 'R' INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); /* NQ is the order of Q */ if (left) { nq = *m; } else { nq = *n; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,nq)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNM2R", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || *k == 0) { return 0; } if (left && ! notran || ! left && notran) { i1 = 1; i2 = *k; i3 = 1; } else { i1 = *k; i2 = 1; i3 = -1; } if (left) { ni = *n; jc = 1; } else { mi = *m; ic = 1; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { if (left) { /* H(i) or H(i)' is applied to C(i:m,1:n) */ mi = *m - i__ + 1; ic = i__; } else { /* H(i) or H(i)' is applied to C(1:m,i:n) */ ni = *n - i__ + 1; jc = i__; } /* Apply H(i) or H(i)' */ if (notran) { i__3 = i__; taui.r = tau[i__3].r, taui.i = tau[i__3].i; } else { d_cnjg(&z__1, &tau[i__]); taui.r = z__1.r, taui.i = z__1.i; } i__3 = i__ + i__ * a_dim1; aii.r = a[i__3].r, aii.i = a[i__3].i; i__3 = i__ + i__ * a_dim1; a[i__3].r = 1., a[i__3].i = 0.; zlarf_(side, &mi, &ni, &a[i__ + i__ * a_dim1], &c__1, &taui, &c__[ic + jc * c_dim1], ldc, &work[1]); i__3 = i__ + i__ * a_dim1; a[i__3].r = aii.r, a[i__3].i = aii.i; /* L10: */ } return 0; /* End of ZUNM2R */ } /* zunm2r_ */ /* Subroutine */ int zunmbr_(char *vect, char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer * lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3[2]; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer i1, i2, nb, mi, ni, nq, nw; static logical left; extern logical lsame_(char *, char *); static integer iinfo; extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static logical notran, applyq; static char transt[1]; static integer lwkopt; static logical lquery; extern /* Subroutine */ int zunmlq_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *), zunmqr_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= If VECT = 'Q', ZUNMBR overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H If VECT = 'P', ZUNMBR overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': P * C C * P TRANS = 'C': P**H * C C * P**H Here Q and P**H are the unitary matrices determined by ZGEBRD when reducing a complex matrix A to bidiagonal form: A = Q * B * P**H. Q and P**H are defined as products of elementary reflectors H(i) and G(i) respectively. Let nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Thus nq is the order of the unitary matrix Q or P**H that is applied. If VECT = 'Q', A is assumed to have been an NQ-by-K matrix: if nq >= k, Q = H(1) H(2) . . . H(k); if nq < k, Q = H(1) H(2) . . . H(nq-1). If VECT = 'P', A is assumed to have been a K-by-NQ matrix: if k < nq, P = G(1) G(2) . . . G(k); if k >= nq, P = G(1) G(2) . . . G(nq-1). Arguments ========= VECT (input) CHARACTER*1 = 'Q': apply Q or Q**H; = 'P': apply P or P**H. SIDE (input) CHARACTER*1 = 'L': apply Q, Q**H, P or P**H from the Left; = 'R': apply Q, Q**H, P or P**H from the Right. TRANS (input) CHARACTER*1 = 'N': No transpose, apply Q or P; = 'C': Conjugate transpose, apply Q**H or P**H. M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER If VECT = 'Q', the number of columns in the original matrix reduced by ZGEBRD. If VECT = 'P', the number of rows in the original matrix reduced by ZGEBRD. K >= 0. A (input) COMPLEX*16 array, dimension (LDA,min(nq,K)) if VECT = 'Q' (LDA,nq) if VECT = 'P' The vectors which define the elementary reflectors H(i) and G(i), whose products determine the matrices Q and P, as returned by ZGEBRD. LDA (input) INTEGER The leading dimension of the array A. If VECT = 'Q', LDA >= max(1,nq); if VECT = 'P', LDA >= max(1,min(nq,K)). TAU (input) COMPLEX*16 array, dimension (min(nq,K)) TAU(i) must contain the scalar factor of the elementary reflector H(i) or G(i) which determines Q or P, as returned by ZGEBRD in the array argument TAUQ or TAUP. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q or P*C or P**H*C or C*P or C*P**H. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M); if N = 0 or M = 0, LWORK >= 1. For optimum performance LWORK >= max(1,N*NB) if SIDE = 'L', and LWORK >= max(1,M*NB) if SIDE = 'R', where NB is the optimal blocksize. (NB = 0 if M = 0 or N = 0.) If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; applyq = lsame_(vect, "Q"); left = lsame_(side, "L"); notran = lsame_(trans, "N"); lquery = *lwork == -1; /* NQ is the order of Q or P and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = *n; } else { nq = *n; nw = *m; } if (*m == 0 || *n == 0) { nw = 0; } if (! applyq && ! lsame_(vect, "P")) { *info = -1; } else if (! left && ! lsame_(side, "R")) { *info = -2; } else if (! notran && ! lsame_(trans, "C")) { *info = -3; } else if (*m < 0) { *info = -4; } else if (*n < 0) { *info = -5; } else if (*k < 0) { *info = -6; } else /* if(complicated condition) */ { /* Computing MAX */ i__1 = 1, i__2 = min(nq,*k); if (applyq && *lda < max(1,nq) || ! applyq && *lda < max(i__1,i__2)) { *info = -8; } else if (*ldc < max(1,*m)) { *info = -11; } else if (*lwork < max(1,nw) && ! lquery) { *info = -13; } } if (*info == 0) { if (nw > 0) { if (applyq) { if (left) { /* Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = *m - 1; i__2 = *m - 1; nb = ilaenv_(&c__1, "ZUNMQR", ch__1, &i__1, n, &i__2, & c_n1, (ftnlen)6, (ftnlen)2); } else { /* Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = *n - 1; i__2 = *n - 1; nb = ilaenv_(&c__1, "ZUNMQR", ch__1, m, &i__1, &i__2, & c_n1, (ftnlen)6, (ftnlen)2); } } else { if (left) { /* Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = *m - 1; i__2 = *m - 1; nb = ilaenv_(&c__1, "ZUNMLQ", ch__1, &i__1, n, &i__2, & c_n1, (ftnlen)6, (ftnlen)2); } else { /* Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = *n - 1; i__2 = *n - 1; nb = ilaenv_(&c__1, "ZUNMLQ", ch__1, m, &i__1, &i__2, & c_n1, (ftnlen)6, (ftnlen)2); } } /* Computing MAX */ i__1 = 1, i__2 = nw * nb; lwkopt = max(i__1,i__2); } else { lwkopt = 1; } work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNMBR", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } if (applyq) { /* Apply Q */ if (nq >= *k) { /* Q was determined by a call to ZGEBRD with nq >= k */ zunmqr_(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], lwork, &iinfo); } else if (nq > 1) { /* Q was determined by a call to ZGEBRD with nq < k */ if (left) { mi = *m - 1; ni = *n; i1 = 2; i2 = 1; } else { mi = *m; ni = *n - 1; i1 = 1; i2 = 2; } i__1 = nq - 1; zunmqr_(side, trans, &mi, &ni, &i__1, &a[a_dim1 + 2], lda, &tau[1] , &c__[i1 + i2 * c_dim1], ldc, &work[1], lwork, &iinfo); } } else { /* Apply P */ if (notran) { *(unsigned char *)transt = 'C'; } else { *(unsigned char *)transt = 'N'; } if (nq > *k) { /* P was determined by a call to ZGEBRD with nq > k */ zunmlq_(side, transt, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], lwork, &iinfo); } else if (nq > 1) { /* P was determined by a call to ZGEBRD with nq <= k */ if (left) { mi = *m - 1; ni = *n; i1 = 2; i2 = 1; } else { mi = *m; ni = *n - 1; i1 = 1; i2 = 2; } i__1 = nq - 1; zunmlq_(side, transt, &mi, &ni, &i__1, &a[(a_dim1 << 1) + 1], lda, &tau[1], &c__[i1 + i2 * c_dim1], ldc, &work[1], lwork, & iinfo); } } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNMBR */ } /* zunmbr_ */ /* Subroutine */ int zunmhr_(char *side, char *trans, integer *m, integer *n, integer *ilo, integer *ihi, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex * work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1[2], i__2; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer i1, i2, nb, mi, nh, ni, nq, nw; static logical left; extern logical lsame_(char *, char *); static integer iinfo; extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static integer lwkopt; static logical lquery; extern /* Subroutine */ int zunmqr_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNMHR overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H where Q is a complex unitary matrix of order nq, with nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of IHI-ILO elementary reflectors, as returned by ZGEHRD: Q = H(ilo) H(ilo+1) . . . H(ihi-1). Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. TRANS (input) CHARACTER*1 = 'N': apply Q (No transpose) = 'C': apply Q**H (Conjugate transpose) M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. ILO (input) INTEGER IHI (input) INTEGER ILO and IHI must have the same values as in the previous call of ZGEHRD. Q is equal to the unit matrix except in the submatrix Q(ilo+1:ihi,ilo+1:ihi). If SIDE = 'L', then 1 <= ILO <= IHI <= M, if M > 0, and ILO = 1 and IHI = 0, if M = 0; if SIDE = 'R', then 1 <= ILO <= IHI <= N, if N > 0, and ILO = 1 and IHI = 0, if N = 0. A (input) COMPLEX*16 array, dimension (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The vectors which define the elementary reflectors, as returned by ZGEHRD. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'. TAU (input) COMPLEX*16 array, dimension (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEHRD. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= N*NB if SIDE = 'L', and LWORK >= M*NB if SIDE = 'R', where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; nh = *ihi - *ilo; left = lsame_(side, "L"); lquery = *lwork == -1; /* NQ is the order of Q and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = *n; } else { nq = *n; nw = *m; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! lsame_(trans, "N") && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*ilo < 1 || *ilo > max(1,nq)) { *info = -5; } else if (*ihi < min(*ilo,nq) || *ihi > nq) { *info = -6; } else if (*lda < max(1,nq)) { *info = -8; } else if (*ldc < max(1,*m)) { *info = -11; } else if (*lwork < max(1,nw) && ! lquery) { *info = -13; } if (*info == 0) { if (left) { /* Writing concatenation */ i__1[0] = 1, a__1[0] = side; i__1[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2); nb = ilaenv_(&c__1, "ZUNMQR", ch__1, &nh, n, &nh, &c_n1, (ftnlen) 6, (ftnlen)2); } else { /* Writing concatenation */ i__1[0] = 1, a__1[0] = side; i__1[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2); nb = ilaenv_(&c__1, "ZUNMQR", ch__1, m, &nh, &nh, &c_n1, (ftnlen) 6, (ftnlen)2); } lwkopt = max(1,nw) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__2 = -(*info); xerbla_("ZUNMHR", &i__2); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || nh == 0) { work[1].r = 1., work[1].i = 0.; return 0; } if (left) { mi = nh; ni = *n; i1 = *ilo + 1; i2 = 1; } else { mi = *m; ni = nh; i1 = 1; i2 = *ilo + 1; } zunmqr_(side, trans, &mi, &ni, &nh, &a[*ilo + 1 + *ilo * a_dim1], lda, & tau[*ilo], &c__[i1 + i2 * c_dim1], ldc, &work[1], lwork, &iinfo); work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNMHR */ } /* zunmhr_ */ /* Subroutine */ int zunml2_(char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *info) { /* System generated locals */ integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3; doublecomplex z__1; /* Builtin functions */ void d_cnjg(doublecomplex *, doublecomplex *); /* Local variables */ static integer i__, i1, i2, i3, ic, jc, mi, ni, nq; static doublecomplex aii; static logical left; static doublecomplex taui; extern logical lsame_(char *, char *); extern /* Subroutine */ int zlarf_(char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *), xerbla_(char *, integer *), zlacgv_(integer *, doublecomplex *, integer *); static logical notran; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNML2 overwrites the general complex m-by-n matrix C with Q * C if SIDE = 'L' and TRANS = 'N', or Q'* C if SIDE = 'L' and TRANS = 'C', or C * Q if SIDE = 'R' and TRANS = 'N', or C * Q' if SIDE = 'R' and TRANS = 'C', where Q is a complex unitary matrix defined as the product of k elementary reflectors Q = H(k)' . . . H(2)' H(1)' as returned by ZGELQF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q' from the Left = 'R': apply Q or Q' from the Right TRANS (input) CHARACTER*1 = 'N': apply Q (No transpose) = 'C': apply Q' (Conjugate transpose) M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. A (input) COMPLEX*16 array, dimension (LDA,M) if SIDE = 'L', (LDA,N) if SIDE = 'R' The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGELQF in the first k rows of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,K). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGELQF. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the m-by-n matrix C. On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) COMPLEX*16 array, dimension (N) if SIDE = 'L', (M) if SIDE = 'R' INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); /* NQ is the order of Q */ if (left) { nq = *m; } else { nq = *n; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,*k)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNML2", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || *k == 0) { return 0; } if (left && notran || ! left && ! notran) { i1 = 1; i2 = *k; i3 = 1; } else { i1 = *k; i2 = 1; i3 = -1; } if (left) { ni = *n; jc = 1; } else { mi = *m; ic = 1; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { if (left) { /* H(i) or H(i)' is applied to C(i:m,1:n) */ mi = *m - i__ + 1; ic = i__; } else { /* H(i) or H(i)' is applied to C(1:m,i:n) */ ni = *n - i__ + 1; jc = i__; } /* Apply H(i) or H(i)' */ if (notran) { d_cnjg(&z__1, &tau[i__]); taui.r = z__1.r, taui.i = z__1.i; } else { i__3 = i__; taui.r = tau[i__3].r, taui.i = tau[i__3].i; } if (i__ < nq) { i__3 = nq - i__; zlacgv_(&i__3, &a[i__ + (i__ + 1) * a_dim1], lda); } i__3 = i__ + i__ * a_dim1; aii.r = a[i__3].r, aii.i = a[i__3].i; i__3 = i__ + i__ * a_dim1; a[i__3].r = 1., a[i__3].i = 0.; zlarf_(side, &mi, &ni, &a[i__ + i__ * a_dim1], lda, &taui, &c__[ic + jc * c_dim1], ldc, &work[1]); i__3 = i__ + i__ * a_dim1; a[i__3].r = aii.r, a[i__3].i = aii.i; if (i__ < nq) { i__3 = nq - i__; zlacgv_(&i__3, &a[i__ + (i__ + 1) * a_dim1], lda); } /* L10: */ } return 0; /* End of ZUNML2 */ } /* zunml2_ */ /* Subroutine */ int zunmlq_(char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3[2], i__4, i__5; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer i__; static doublecomplex t[4160] /* was [65][64] */; static integer i1, i2, i3, ib, ic, jc, nb, mi, ni, nq, nw, iws; static logical left; extern logical lsame_(char *, char *); static integer nbmin, iinfo; extern /* Subroutine */ int zunml2_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static logical notran; static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static char transt[1]; static integer lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNMLQ overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H where Q is a complex unitary matrix defined as the product of k elementary reflectors Q = H(k)' . . . H(2)' H(1)' as returned by ZGELQF. Q is of order M if SIDE = 'L' and of order N if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. TRANS (input) CHARACTER*1 = 'N': No transpose, apply Q; = 'C': Conjugate transpose, apply Q**H. M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. A (input) COMPLEX*16 array, dimension (LDA,M) if SIDE = 'L', (LDA,N) if SIDE = 'R' The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGELQF in the first k rows of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,K). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGELQF. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= N*NB if SIDE 'L', and LWORK >= M*NB if SIDE = 'R', where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); lquery = *lwork == -1; /* NQ is the order of Q and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = *n; } else { nq = *n; nw = *m; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,*k)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } else if (*lwork < max(1,nw) && ! lquery) { *info = -12; } if (*info == 0) { /* Determine the block size. NB may be at most NBMAX, where NBMAX is used to define the local array T. Computing MIN Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 64, i__2 = ilaenv_(&c__1, "ZUNMLQ", ch__1, m, n, k, &c_n1, ( ftnlen)6, (ftnlen)2); nb = min(i__1,i__2); lwkopt = max(1,nw) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNMLQ", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || *k == 0) { work[1].r = 1., work[1].i = 0.; return 0; } nbmin = 2; ldwork = nw; if (nb > 1 && nb < *k) { iws = nw * nb; if (*lwork < iws) { nb = *lwork / ldwork; /* Computing MAX Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 2, i__2 = ilaenv_(&c__2, "ZUNMLQ", ch__1, m, n, k, &c_n1, ( ftnlen)6, (ftnlen)2); nbmin = max(i__1,i__2); } } else { iws = nw; } if (nb < nbmin || nb >= *k) { /* Use unblocked code */ zunml2_(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], &iinfo); } else { /* Use blocked code */ if (left && notran || ! left && ! notran) { i1 = 1; i2 = *k; i3 = nb; } else { i1 = (*k - 1) / nb * nb + 1; i2 = 1; i3 = -nb; } if (left) { ni = *n; jc = 1; } else { mi = *m; ic = 1; } if (notran) { *(unsigned char *)transt = 'C'; } else { *(unsigned char *)transt = 'N'; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__4 = nb, i__5 = *k - i__ + 1; ib = min(i__4,i__5); /* Form the triangular factor of the block reflector H = H(i) H(i+1) . . . H(i+ib-1) */ i__4 = nq - i__ + 1; zlarft_("Forward", "Rowwise", &i__4, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], t, &c__65); if (left) { /* H or H' is applied to C(i:m,1:n) */ mi = *m - i__ + 1; ic = i__; } else { /* H or H' is applied to C(1:m,i:n) */ ni = *n - i__ + 1; jc = i__; } /* Apply H or H' */ zlarfb_(side, transt, "Forward", "Rowwise", &mi, &ni, &ib, &a[i__ + i__ * a_dim1], lda, t, &c__65, &c__[ic + jc * c_dim1], ldc, &work[1], &ldwork); /* L10: */ } } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNMLQ */ } /* zunmlq_ */ /* Subroutine */ int zunmql_(char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3[2], i__4, i__5; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer i__; static doublecomplex t[4160] /* was [65][64] */; static integer i1, i2, i3, ib, nb, mi, ni, nq, nw, iws; static logical left; extern logical lsame_(char *, char *); static integer nbmin, iinfo; extern /* Subroutine */ int zunm2l_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static logical notran; static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNMQL overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H where Q is a complex unitary matrix defined as the product of k elementary reflectors Q = H(k) . . . H(2) H(1) as returned by ZGEQLF. Q is of order M if SIDE = 'L' and of order N if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. TRANS (input) CHARACTER*1 = 'N': No transpose, apply Q; = 'C': Transpose, apply Q**H. M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. A (input) COMPLEX*16 array, dimension (LDA,K) The i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQLF in the last k columns of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. If SIDE = 'L', LDA >= max(1,M); if SIDE = 'R', LDA >= max(1,N). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQLF. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= N*NB if SIDE = 'L', and LWORK >= M*NB if SIDE = 'R', where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); lquery = *lwork == -1; /* NQ is the order of Q and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = max(1,*n); } else { nq = *n; nw = max(1,*m); } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,nq)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } if (*info == 0) { if (*m == 0 || *n == 0) { lwkopt = 1; } else { /* Determine the block size. NB may be at most NBMAX, where NBMAX is used to define the local array T. Computing MIN Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 64, i__2 = ilaenv_(&c__1, "ZUNMQL", ch__1, m, n, k, &c_n1, (ftnlen)6, (ftnlen)2); nb = min(i__1,i__2); lwkopt = nw * nb; } work[1].r = (doublereal) lwkopt, work[1].i = 0.; if (*lwork < nw && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNMQL", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } nbmin = 2; ldwork = nw; if (nb > 1 && nb < *k) { iws = nw * nb; if (*lwork < iws) { nb = *lwork / ldwork; /* Computing MAX Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 2, i__2 = ilaenv_(&c__2, "ZUNMQL", ch__1, m, n, k, &c_n1, ( ftnlen)6, (ftnlen)2); nbmin = max(i__1,i__2); } } else { iws = nw; } if (nb < nbmin || nb >= *k) { /* Use unblocked code */ zunm2l_(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], &iinfo); } else { /* Use blocked code */ if (left && notran || ! left && ! notran) { i1 = 1; i2 = *k; i3 = nb; } else { i1 = (*k - 1) / nb * nb + 1; i2 = 1; i3 = -nb; } if (left) { ni = *n; } else { mi = *m; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__4 = nb, i__5 = *k - i__ + 1; ib = min(i__4,i__5); /* Form the triangular factor of the block reflector H = H(i+ib-1) . . . H(i+1) H(i) */ i__4 = nq - *k + i__ + ib - 1; zlarft_("Backward", "Columnwise", &i__4, &ib, &a[i__ * a_dim1 + 1] , lda, &tau[i__], t, &c__65); if (left) { /* H or H' is applied to C(1:m-k+i+ib-1,1:n) */ mi = *m - *k + i__ + ib - 1; } else { /* H or H' is applied to C(1:m,1:n-k+i+ib-1) */ ni = *n - *k + i__ + ib - 1; } /* Apply H or H' */ zlarfb_(side, trans, "Backward", "Columnwise", &mi, &ni, &ib, &a[ i__ * a_dim1 + 1], lda, t, &c__65, &c__[c_offset], ldc, & work[1], &ldwork); /* L10: */ } } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNMQL */ } /* zunmql_ */ /* Subroutine */ int zunmqr_(char *side, char *trans, integer *m, integer *n, integer *k, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3[2], i__4, i__5; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer i__; static doublecomplex t[4160] /* was [65][64] */; static integer i1, i2, i3, ib, ic, jc, nb, mi, ni, nq, nw, iws; static logical left; extern logical lsame_(char *, char *); static integer nbmin, iinfo; extern /* Subroutine */ int zunm2r_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); extern /* Subroutine */ int zlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *); static logical notran; static integer ldwork; extern /* Subroutine */ int zlarft_(char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *); static integer lwkopt; static logical lquery; /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNMQR overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H where Q is a complex unitary matrix defined as the product of k elementary reflectors Q = H(1) H(2) . . . H(k) as returned by ZGEQRF. Q is of order M if SIDE = 'L' and of order N if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. TRANS (input) CHARACTER*1 = 'N': No transpose, apply Q; = 'C': Conjugate transpose, apply Q**H. M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. A (input) COMPLEX*16 array, dimension (LDA,K) The i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGEQRF in the first k columns of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. If SIDE = 'L', LDA >= max(1,M); if SIDE = 'R', LDA >= max(1,N). TAU (input) COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQRF. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= N*NB if SIDE = 'L', and LWORK >= M*NB if SIDE = 'R', where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); lquery = *lwork == -1; /* NQ is the order of Q and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = *n; } else { nq = *n; nw = *m; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "C")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,nq)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } else if (*lwork < max(1,nw) && ! lquery) { *info = -12; } if (*info == 0) { /* Determine the block size. NB may be at most NBMAX, where NBMAX is used to define the local array T. Computing MIN Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 64, i__2 = ilaenv_(&c__1, "ZUNMQR", ch__1, m, n, k, &c_n1, ( ftnlen)6, (ftnlen)2); nb = min(i__1,i__2); lwkopt = max(1,nw) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__1 = -(*info); xerbla_("ZUNMQR", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || *k == 0) { work[1].r = 1., work[1].i = 0.; return 0; } nbmin = 2; ldwork = nw; if (nb > 1 && nb < *k) { iws = nw * nb; if (*lwork < iws) { nb = *lwork / ldwork; /* Computing MAX Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 2, i__2 = ilaenv_(&c__2, "ZUNMQR", ch__1, m, n, k, &c_n1, ( ftnlen)6, (ftnlen)2); nbmin = max(i__1,i__2); } } else { iws = nw; } if (nb < nbmin || nb >= *k) { /* Use unblocked code */ zunm2r_(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], &iinfo); } else { /* Use blocked code */ if (left && ! notran || ! left && notran) { i1 = 1; i2 = *k; i3 = nb; } else { i1 = (*k - 1) / nb * nb + 1; i2 = 1; i3 = -nb; } if (left) { ni = *n; jc = 1; } else { mi = *m; ic = 1; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__4 = nb, i__5 = *k - i__ + 1; ib = min(i__4,i__5); /* Form the triangular factor of the block reflector H = H(i) H(i+1) . . . H(i+ib-1) */ i__4 = nq - i__ + 1; zlarft_("Forward", "Columnwise", &i__4, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], t, &c__65) ; if (left) { /* H or H' is applied to C(i:m,1:n) */ mi = *m - i__ + 1; ic = i__; } else { /* H or H' is applied to C(1:m,i:n) */ ni = *n - i__ + 1; jc = i__; } /* Apply H or H' */ zlarfb_(side, trans, "Forward", "Columnwise", &mi, &ni, &ib, &a[ i__ + i__ * a_dim1], lda, t, &c__65, &c__[ic + jc * c_dim1], ldc, &work[1], &ldwork); /* L10: */ } } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNMQR */ } /* zunmqr_ */ /* Subroutine */ int zunmtr_(char *side, char *uplo, char *trans, integer *m, integer *n, doublecomplex *a, integer *lda, doublecomplex *tau, doublecomplex *c__, integer *ldc, doublecomplex *work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1[2], i__2, i__3; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ static integer i1, i2, nb, mi, ni, nq, nw; static logical left; extern logical lsame_(char *, char *); static integer iinfo; static logical upper; extern /* Subroutine */ int xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); static integer lwkopt; static logical lquery; extern /* Subroutine */ int zunmql_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *), zunmqr_(char *, char *, integer *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *, integer *); /* -- LAPACK routine (version 3.2) -- -- LAPACK is a software package provided by Univ. of Tennessee, -- -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- November 2006 Purpose ======= ZUNMTR overwrites the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'C': Q**H * C C * Q**H where Q is a complex unitary matrix of order nq, with nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of nq-1 elementary reflectors, as returned by ZHETRD: if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1); if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1). Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. UPLO (input) CHARACTER*1 = 'U': Upper triangle of A contains elementary reflectors from ZHETRD; = 'L': Lower triangle of A contains elementary reflectors from ZHETRD. TRANS (input) CHARACTER*1 = 'N': No transpose, apply Q; = 'C': Conjugate transpose, apply Q**H. M (input) INTEGER The number of rows of the matrix C. M >= 0. N (input) INTEGER The number of columns of the matrix C. N >= 0. A (input) COMPLEX*16 array, dimension (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The vectors which define the elementary reflectors, as returned by ZHETRD. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'. TAU (input) COMPLEX*16 array, dimension (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZHETRD. C (input/output) COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= N*NB if SIDE = 'L', and LWORK >=M*NB if SIDE = 'R', where NB is the optimal blocksize. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value ===================================================================== Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); upper = lsame_(uplo, "U"); lquery = *lwork == -1; /* NQ is the order of Q and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = *n; } else { nq = *n; nw = *m; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! upper && ! lsame_(uplo, "L")) { *info = -2; } else if (! lsame_(trans, "N") && ! lsame_(trans, "C")) { *info = -3; } else if (*m < 0) { *info = -4; } else if (*n < 0) { *info = -5; } else if (*lda < max(1,nq)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } else if (*lwork < max(1,nw) && ! lquery) { *info = -12; } if (*info == 0) { if (upper) { if (left) { /* Writing concatenation */ i__1[0] = 1, a__1[0] = side; i__1[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2); i__2 = *m - 1; i__3 = *m - 1; nb = ilaenv_(&c__1, "ZUNMQL", ch__1, &i__2, n, &i__3, &c_n1, ( ftnlen)6, (ftnlen)2); } else { /* Writing concatenation */ i__1[0] = 1, a__1[0] = side; i__1[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2); i__2 = *n - 1; i__3 = *n - 1; nb = ilaenv_(&c__1, "ZUNMQL", ch__1, m, &i__2, &i__3, &c_n1, ( ftnlen)6, (ftnlen)2); } } else { if (left) { /* Writing concatenation */ i__1[0] = 1, a__1[0] = side; i__1[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2); i__2 = *m - 1; i__3 = *m - 1; nb = ilaenv_(&c__1, "ZUNMQR", ch__1, &i__2, n, &i__3, &c_n1, ( ftnlen)6, (ftnlen)2); } else { /* Writing concatenation */ i__1[0] = 1, a__1[0] = side; i__1[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__1, &c__2, (ftnlen)2); i__2 = *n - 1; i__3 = *n - 1; nb = ilaenv_(&c__1, "ZUNMQR", ch__1, m, &i__2, &i__3, &c_n1, ( ftnlen)6, (ftnlen)2); } } lwkopt = max(1,nw) * nb; work[1].r = (doublereal) lwkopt, work[1].i = 0.; } if (*info != 0) { i__2 = -(*info); xerbla_("ZUNMTR", &i__2); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || nq == 1) { work[1].r = 1., work[1].i = 0.; return 0; } if (left) { mi = *m - 1; ni = *n; } else { mi = *m; ni = *n - 1; } if (upper) { /* Q was determined by a call to ZHETRD with UPLO = 'U' */ i__2 = nq - 1; zunmql_(side, trans, &mi, &ni, &i__2, &a[(a_dim1 << 1) + 1], lda, & tau[1], &c__[c_offset], ldc, &work[1], lwork, &iinfo); } else { /* Q was determined by a call to ZHETRD with UPLO = 'L' */ if (left) { i1 = 2; i2 = 1; } else { i1 = 1; i2 = 2; } i__2 = nq - 1; zunmqr_(side, trans, &mi, &ni, &i__2, &a[a_dim1 + 2], lda, &tau[1], & c__[i1 + i2 * c_dim1], ldc, &work[1], lwork, &iinfo); } work[1].r = (doublereal) lwkopt, work[1].i = 0.; return 0; /* End of ZUNMTR */ } /* zunmtr_ */