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/* Generate some test cases using fftw3 */
#include <stdlib.h>
#include <stdio.h>
#include <fftw3.h>
void dump_vector(int n, double* vec) {
for(int i = 0; i < n; i++)
printf("%20.15f ", vec[i]);
printf("\n");
}
void dct(int flag, int n) {
double* in = malloc( n * sizeof(double));
double* out = malloc( n * sizeof(double));
//
fftw_plan plan = fftw_plan_r2r_1d(n, in, out, flag, FFTW_ESTIMATE);
for( int k = 0; k < n; k++) {
// Init input vector
for( int i = 0; i < n; i++)
in[i] = 0;
in[k] = 1;
// Perform DFT
fftw_execute(plan);
// Print results
dump_vector(n, in );
dump_vector(n, out);
printf("\n");
}
//
free(in);
free(out);
fftw_destroy_plan(plan);
}
int main(void)
{
printf("DCT II (the DCT)\n");
dct( FFTW_REDFT10, 2);
dct( FFTW_REDFT10, 4);
printf("DCT III (Inverse DCT)\n");
dct( FFTW_REDFT01, 2);
dct( FFTW_REDFT01, 4);
return 0;
}
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