// ft using GSL
void ft_gsl(size_t N, const cmpvec& little_x, cmpvec& big_X)
{
big_X.clear();
FFTCalc fftCalc(N);
fftCalc.setData(little_x);
fftCalc.performFFT();
fftCalc.getData(big_X);
assert(little_x.size() == big_X.size());
}
void FFT::dofft86(long (*x)[2], const int bits)
{
unsigned int i,j;
long *xe=x[1<<bits];//position du dernier element
long *xi; //position actuelle
long curcos,cursin;
for (i=POW-bits; i<POW; ++i)//i:0->1->2->...->11
{
const unsigned long s2dk=SAMPLES2>>i;//1024->512->256->128->64->32->16->8->4->2->1
const unsigned long d2=s2dk<<1;//*2
for (j=0; j<s2dk; ++j)
{
curcos=cossintab[j<<i][0];// posi cos actuelle
cursin=cossintab[j<<i][1];// posi sin actuelle
for (xi=x[j]; xi<xe; xi=xi+(d2<<1)) //*2
fftCalc(xi, curcos,cursin, d2);
}
}
}
