libdspl-2.0/examples/src/ifft_cmplx_test.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "dspl.h"

#define N 18

int main()
{
    void* handle;           /* DSPL handle                  */
    handle = dspl_load();   /* Load libdspl                 */
    complex_t x[N];         /* Input signal array           */
    complex_t y[N];         /* FFT Output signal array      */
    complex_t z[N];         /* IFFT Output signal array     */
    fft_t pfft = {0};       /* FFT object (fill zeros)      */
    int k;

    /* Fill FFT structure                                    */
    fft_create(&pfft, N);

    /* Fill input signal x[k] = exp(j*k)                     */
    for(k = 0; k < N; k++)
    {
        RE(x[k]) = (double)cos((double)k);
        IM(x[k]) = (double)sin((double)k);
    }

    /* FFT                                                  */
    fft_cmplx(x, N, &pfft, y);

    /* FFT                                                  */
    ifft_cmplx(y, N, &pfft, z);

    /* print result                                         */
    for(k = 0; k < N; k++)
    {
        printf("| x[%2d] = %9.3f%9.3f ",    k, RE(x[k]), IM(x[k]));
        printf("| y[%2d] = %9.3f%9.3f ",    k, RE(y[k]), IM(y[k]));
        printf("| z[%2d] = %9.3f%9.3f |\n", k, RE(z[k]), IM(z[k]));
    }
    fft_free(&pfft);        /* Clear fft_t object          */
    dspl_free(handle);      /* Clear DSPL handle           */
    return 0;
}