| 1 | #-----------------------------------------------------------------------------
|
| 2 | #
|
| 3 | # Author : philippe.billet@noos.fr
|
| 4 | #
|
| 5 | # erfc(x)
|
| 6 | #
|
| 7 | # GW Added erfc() from Numerical Recipes in C
|
| 8 | #
|
| 9 | #-----------------------------------------------------------------------------
|
| 10 |
|
| 11 |
|
| 12 |
|
| 13 | Eval_erfc = ->
|
| 14 | push(cadr(p1))
|
| 15 | Eval()
|
| 16 | yerfc()
|
| 17 |
|
| 18 | yerfc = ->
|
| 19 | save()
|
| 20 | yyerfc()
|
| 21 | restore()
|
| 22 |
|
| 23 | yyerfc = ->
|
| 24 | d = 0.0
|
| 25 |
|
| 26 | p1 = pop()
|
| 27 |
|
| 28 | if (isdouble(p1))
|
| 29 | d = erfc(p1.d)
|
| 30 | push_double(d)
|
| 31 | return
|
| 32 |
|
| 33 | push_symbol(ERFC)
|
| 34 | push(p1)
|
| 35 | list(2)
|
| 36 | return
|
| 37 |
|
| 38 | # from Numerical Recipes in C
|
| 39 |
|
| 40 | #ifndef LINUX
|
| 41 | erfc = (x) ->
|
| 42 | t = 0.0
|
| 43 | z = 0.0
|
| 44 | ans = 0.0
|
| 45 |
|
| 46 | z = Math.abs(x)
|
| 47 | t = 1.0 / (1.0 + 0.5 * z)
|
| 48 |
|
| 49 | ans=t*Math.exp(-z*z-1.26551223+t*(1.00002368+t*(0.37409196+t*(0.09678418+
|
| 50 | t*(-0.18628806+t*(0.27886807+t*(-1.13520398+t*(1.48851587+
|
| 51 | t*(-0.82215223+t*0.17087277)))))))))
|
| 52 |
|
| 53 | if x >= 0.0
|
| 54 | return ans
|
| 55 | else
|
| 56 | return 2.0-ans
|
| 57 | #endif
|
| 58 |
|
| 59 |
|
| 60 | ###
|
| 61 | # commented-out test
|
| 62 | "float(erfc(1))",
|
| 63 | "0.157299",
|
| 64 | ###
|
| 65 |
|