1 | #-----------------------------------------------------------------------------
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2 | #
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3 | # Author : philippe.billet@noos.fr
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4 | #
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5 | # Dirac function dirac(x)
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6 | # dirac(-x)=dirac(x)
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7 | # dirac(b-a)=dirac(a-b)
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8 | #-----------------------------------------------------------------------------
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9 |
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10 |
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11 |
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12 | Eval_dirac = ->
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13 | push(cadr(p1))
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14 | Eval()
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15 | dirac()
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16 |
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17 | dirac = ->
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18 | save()
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19 | ydirac()
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20 | restore()
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21 |
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22 | #define p1 p1
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23 |
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24 | ydirac = ->
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25 |
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26 | p1 = pop()
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27 |
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28 |
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29 |
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30 | if (isdouble(p1))
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31 | if (p1.d == 0)
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32 | push_integer(1)
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33 | return
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34 | else
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35 | push_integer(0)
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36 | return
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37 |
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38 | if (isrational(p1))
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39 | if (MZERO(mmul(p1.q.a,p1.q.b)))
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40 | push_integer(1)
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41 | return
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42 | else
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43 | push_integer(0)
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44 | return
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45 |
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46 |
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47 | if (car(p1) == symbol(POWER))
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48 | push_symbol(DIRAC)
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49 | push(cadr(p1))
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50 | list(2)
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51 | return
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52 |
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53 | if (isnegativeterm(p1))
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54 | push_symbol(DIRAC)
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55 | push(p1)
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56 | negate()
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57 | list(2)
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58 | return
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59 |
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60 | if (isnegativeterm(p1) || (car(p1) == symbol(ADD) && isnegativeterm(cadr(p1))))
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61 | push(p1)
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62 | negate()
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63 | p1 = pop()
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64 |
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65 |
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66 | push_symbol(DIRAC)
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67 | push(p1)
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68 | list(2)
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69 |
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