Mercurial > pygar
annotate modules/bluespec/Pygar/common/DFT.cpp @ 67:0ede0715dbd6 pygar svn.68
[svn r68] added sensible benchmarks
author | rlm |
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date | Tue, 11 May 2010 23:23:21 -0400 |
parents | 74716e9a81cc |
children |
rev | line source |
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rlm@8 | 1 #include <stdio.h> |
rlm@8 | 2 #include <stdlib.h> |
rlm@8 | 3 #include <math.h> |
rlm@8 | 4 |
rlm@8 | 5 |
rlm@8 | 6 int DFT(int dir,int m,double *x1,double *y1) |
rlm@8 | 7 { |
rlm@8 | 8 long i,k; |
rlm@8 | 9 double arg; |
rlm@8 | 10 double cosarg,sinarg; |
rlm@8 | 11 double *x2=NULL,*y2=NULL; |
rlm@8 | 12 |
rlm@8 | 13 x2 = (double *)(malloc(m*sizeof(double))); |
rlm@8 | 14 y2 = (double *)(malloc(m*sizeof(double))); |
rlm@8 | 15 if (x2 == NULL || y2 == NULL) |
rlm@8 | 16 return 0; |
rlm@8 | 17 |
rlm@8 | 18 for (i=0;i<m;i++) { |
rlm@8 | 19 x2[i] = 0; |
rlm@8 | 20 y2[i] = 0; |
rlm@8 | 21 arg = - dir * 2.0 * 3.141592654 * (double)i / (double)m; |
rlm@8 | 22 for (k=0;k<m;k++) { |
rlm@8 | 23 cosarg = cos(k * arg); |
rlm@8 | 24 sinarg = sin(k * arg); |
rlm@8 | 25 x2[i] += (x1[k] * cosarg - y1[k] * sinarg); |
rlm@8 | 26 y2[i] += (x1[k] * sinarg + y1[k] * cosarg); |
rlm@8 | 27 } |
rlm@8 | 28 } |
rlm@8 | 29 |
rlm@8 | 30 /* Copy the data back */ |
rlm@8 | 31 if (dir == 1) { |
rlm@8 | 32 for (i=0;i<m;i++) { |
rlm@8 | 33 x1[i] = x2[i]; |
rlm@8 | 34 y1[i] = y2[i]; |
rlm@8 | 35 } |
rlm@8 | 36 } else { |
rlm@8 | 37 for (i=0;i<m;i++) { |
rlm@8 | 38 x1[i] = x2[i]; |
rlm@8 | 39 y1[i] = y2[i]; |
rlm@8 | 40 } |
rlm@8 | 41 } |
rlm@8 | 42 |
rlm@8 | 43 free(x2); |
rlm@8 | 44 free(y2); |
rlm@8 | 45 return 1; |
rlm@8 | 46 } |