mirror of
https://github.com/cookiengineer/audacity
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103 lines
2.0 KiB
C
103 lines
2.0 KiB
C
/* A program to test real 2d forward and inverse fast fourier transform routines */
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#include <stdio.h>
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#include <stdlib.h>
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#include <fp.h>
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#include <math.h>
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#include "fftlib.h"
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#include "fftext.h"
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#include "fft2d.h"
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#if macintosh
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#include <timer.h>
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#endif
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#define BIPRAND(a) (2.0/(RAND_MAX+1.0)*a-1.0)
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void main(){
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long N2 = 64; /* the number of rows in 2d ffts, must be power of 2 */
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long N = 256; /* the number of cols in 2d ffts, must be power of 2 */
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float *a;
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float maxerrfft;
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long i1;
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long TheErr;
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long M;
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long M2;
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FILE *fdataout; /* output file */
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unsigned int randseed = 777;
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int rannum;
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#if macintosh
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UnsignedWide TheTime1;
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Microseconds(&TheTime1);
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randseed = TheTime1.lo;
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#endif
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printf(" %6d Byte Floats \n", sizeof(a[0]));
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printf(" randseed = %10u\n", randseed);
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srand(randseed);
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M = roundtol(LOG2(N));
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N = POW2(M);
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M2 = roundtol(LOG2(N2));
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N2 = POW2(M2);
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printf("fft size = %6d X%6d, ", N2, N);
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TheErr = 0;
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if(!TheErr){
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TheErr = fft2dInit(M2, M);
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}
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a = (float *) malloc(N2*N*sizeof(float) );
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if (a == 0) TheErr = 2;
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if(!TheErr){
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fdataout = fopen("fftdat.dr2", "wb");
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if (fdataout == NULL) TheErr = -50;
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}
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if(!TheErr){
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/* write sizes to fdataout */
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fwrite(&N, sizeof(N), 1, fdataout);
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fwrite(&N2, sizeof(N2), 1, fdataout);
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/* set up a simple test case and write to fdataout */
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for (i1=0; i1<N2*N; i1++){
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rannum = rand();
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a[i1] = BIPRAND(rannum);
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}
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fwrite(a, N2*N*sizeof(float), 1, fdataout);
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/* real, 2d fast fourier transform */
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rfft2d(a, M2, M);
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/* write out answer */
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fwrite(a, N2*N*sizeof(float), 1, fdataout);
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fclose(fdataout);
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/* compute and check inverse transform */
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rifft2d(a, M2, M);
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maxerrfft = 0;
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srand(randseed);
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for (i1=0; i1<N2*N; i1++){
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rannum = rand();
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maxerrfft = fmax(maxerrfft, fabs(BIPRAND(rannum)-a[i1]));
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}
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printf("maxerr rfft = %6.4e\n", maxerrfft);
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free(a);
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fft2dFree();
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}
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else{
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if(TheErr==2) printf(" out of memory \n");
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else printf(" error \n");
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fft2dFree();
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}
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printf(" Done. \n");
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return;
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}
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