mirror of
https://github.com/cookiengineer/audacity
synced 2025-06-17 08:30:06 +02:00
131 lines
2.9 KiB
C
131 lines
2.9 KiB
C
/* A program to test 2d complex forward and inverse fast fourier transform routines */
|
|
|
|
#include <NR.H> /* uses fourn from numerical recipes in C to verify ifft2d */
|
|
/*change fmin in numerical recipes to fminnr to avoid conflict with fp.h */
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <fp.h>
|
|
#include <math.h>
|
|
#include "fftlib.h"
|
|
#include "fftext.h"
|
|
#include "fft2d.h"
|
|
|
|
#if macintosh
|
|
#include <timer.h>
|
|
#endif
|
|
|
|
#define NSIZES 24 /* the number of different ffts col sizes to test */
|
|
|
|
#define BIPRAND(a) (2.0/(RAND_MAX+1.0)*a-1.0)
|
|
//#define BIPRAND(a) round(100*(2.0/(RAND_MAX+1.0)*a-1.0))
|
|
typedef struct{
|
|
float Re;
|
|
float Im;
|
|
} Complex;
|
|
|
|
void main(){
|
|
long fftSize[NSIZES] = /* size of FFTs cols, must be powers of 2 */
|
|
{2, 4, 8, 16, 32, 64, 128, 256,
|
|
512, 1024, 2048, 4096, 8192, 16384, 32768, 65536,
|
|
131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216};
|
|
Complex *a1;
|
|
long N2 = 64; /* the number of rows in the 2d fft */
|
|
long isize;
|
|
long i1;
|
|
long TheErr;
|
|
long N;
|
|
long M;
|
|
long M2;
|
|
float maxerrifft;
|
|
float maxerrfft;
|
|
unsigned long nn[2];
|
|
|
|
unsigned int randseed = 777;
|
|
int rannum;
|
|
#if macintosh
|
|
UnsignedWide TheTime1;
|
|
Microseconds(&TheTime1);
|
|
randseed = TheTime1.lo;
|
|
#endif
|
|
|
|
printf(" %6d Byte Floats \n", sizeof(a1[0].Re));
|
|
printf(" randseed = %10u\n", randseed);
|
|
for (isize = 0; isize < NSIZES; isize++){
|
|
|
|
srand(randseed);
|
|
N = fftSize[isize];
|
|
M = roundtol(LOG2(N));
|
|
N = POW2(M);
|
|
M2 = roundtol(LOG2(N2));
|
|
N2 = POW2(M2);
|
|
|
|
printf("ffts size = %6d X%6d, ", N2, N);
|
|
|
|
nn[0] = N2;
|
|
nn[1] = N;
|
|
|
|
TheErr = fft2dInit(M2, M);
|
|
|
|
if(!TheErr){
|
|
a1 = (Complex *) malloc(N2*N*sizeof(Complex) );
|
|
if (a1 == 0) TheErr = 2;
|
|
}
|
|
|
|
if(!TheErr){
|
|
|
|
/* set up a simple test case */
|
|
for (i1=0; i1<N2*N; i1++){
|
|
rannum = rand();
|
|
a1[i1].Re = BIPRAND(rannum);
|
|
rannum = rand();
|
|
a1[i1].Im = BIPRAND(rannum);
|
|
}
|
|
|
|
/* first use fourn from numerical recipes in C to verify ifft2d */
|
|
/* Note their inverse fft is really the conventional forward fft */
|
|
fourn((float *)a1-1, nn-1, 2, -1);
|
|
|
|
ifft2d((float *)a1, M2, M);
|
|
|
|
maxerrifft = 0;
|
|
srand(randseed);
|
|
for (i1=0; i1<N2*N; i1++){
|
|
rannum = rand();
|
|
maxerrifft = fmax(maxerrifft, fabs(BIPRAND(rannum)-a1[i1].Re));
|
|
a1[i1].Re = BIPRAND(rannum);
|
|
rannum = rand();
|
|
maxerrifft = fmax(maxerrifft, fabs(BIPRAND(rannum)-a1[i1].Im));
|
|
a1[i1].Im = BIPRAND(rannum);
|
|
}
|
|
|
|
printf("maxerrifft = %6.4e, ", maxerrifft);
|
|
|
|
/* now use iffts to verify ffts */
|
|
ifft2d((float *)a1, M2, M);
|
|
fft2d((float *)a1, M2, M);
|
|
|
|
maxerrfft = 0;
|
|
srand(randseed);
|
|
for (i1=0; i1<N2*N; i1++){
|
|
rannum = rand();
|
|
maxerrfft = fmax(maxerrfft, fabs(BIPRAND(rannum)-a1[i1].Re));
|
|
rannum = rand();
|
|
maxerrfft = fmax(maxerrfft, fabs(BIPRAND(rannum)-a1[i1].Im));
|
|
}
|
|
|
|
printf("maxerrfft = %6.4e\n", maxerrfft);
|
|
|
|
free(a1);
|
|
fft2dFree();
|
|
}
|
|
else{
|
|
if(TheErr==2) printf(" out of memory \n");
|
|
else printf(" error \n");
|
|
fft2dFree();
|
|
}
|
|
}
|
|
printf(" Done. \n");
|
|
return;
|
|
}
|