#include "kiss_fft.h"

void check(kiss_fft_cpx  * in,kiss_fft_cpx  * out,int nfft,int isinverse)

{

    int bin,k;

    double errpow=0,sigpow=0;

    for (bin=0;bin

        double ansr = 0;

        double ansi = 0;

        double difr;

        double difi;

        for (k=0;k

            double phase = -2*M_PI*bin*k/nfft;

            double re = cos(phase);

            double im = sin(phase);

            if (isinverse)

                im = -im;

#ifdef FIXED_POINT

            re /= nfft;

            im /= nfft;

#endif            

            ansr += in[k].r * re - in[k].i * im;

            ansi += in[k].r * im + in[k].i * re;

        }

        difr = ansr - out[bin].r;

        difi = ansi - out[bin].i;

        errpow += difr*difr + difi*difi;

        sigpow += ansr*ansr+ansi*ansi;

    }

    printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,10*log10(sigpow/errpow) );

}

void test1d(int nfft,int isinverse)

{

    size_t buflen = sizeof(kiss_fft_cpx)*nfft;

    kiss_fft_cpx  * in = (kiss_fft_cpx*)malloc(buflen);

    kiss_fft_cpx  * out= (kiss_fft_cpx*)malloc(buflen);

    kiss_fft_cfg  cfg = kiss_fft_alloc(nfft,isinverse,0,0);

    int k;

    for (k=0;k

        in[k].r = (rand() % 65536) - 32768;

        in[k].i = (rand() % 65536) - 32768;

    }

    kiss_fft(cfg,in,out);

    check(in,out,nfft,isinverse);

    free(in);

    free(out);

    free(cfg);

}

int main(int argc,char ** argv)

{

    if (argc>1) {

        int k;

        for (k=1;k

            test1d(atoi(argv[k]),0);

            test1d(atoi(argv[k]),1);

        }

    }else{

        test1d(32,0);

        test1d(32,1);

    }

    return 0;

}