/* 1D Fourier transform:
Simply call stockham with proper arguments.
Allocated working space of size n dynamically.
*/
void fft(std::vector<complex>::iterator x, int n, int flag)
{
std::vector<complex> y(n);
assert(1 == flag || -1 == flag);
//y = (complex *) malloc( n*sizeof(complex) );
//assert(NULL != y);
stockham(x, n, flag, 1, y.begin());
//free(y);
}
/* 1D Fourier transform:
Simply call stockham with proper arguments.
Allocated working space of size n dynamically.
*/
void fft(complex x[], int n, int flag)
{
complex *y;
assert(1 == flag || -1 == flag);
y = (complex *) malloc( n*sizeof(complex) );
assert(NULL != y);
stockham(x, n, flag, 1, y);
free(y);
}
void fft3D(complex x[], int n1, int n2, int n3, int flag)
{
complex *y;
int i, n, n23;
assert(1 == flag || -1 == flag);
n23 = n2*n3;
n = n1*n23;
y = (complex *) malloc( n23*sizeof(complex) );
assert(NULL != y);
for(i=0; i < n; i += n3) { /* FFT in z */
stockham(x+i, n3, flag, 1, y);
}
for(i=0; i < n; i += n23) { /* FFT in y */
stockham(x+i, n23, flag, n3, y);
}
free(y);
cooley_tukey(x, n, flag, n23); /* FFT in x */
}
void fft2D(std::vector<complex>::iterator x, int n1, int n2, int flag)
{
std::vector<complex> y(n2);
int i, n;
assert(1 == flag || -1 == flag);
n = n1*n2;
/*y = (complex *) malloc( n2*sizeof(complex) );
assert(NULL != y);*/
for(i=0; i < n; i += n2) { /* FFT in y */
stockham(x+i, n2, flag, 1, y.begin());
}
//free(y);
cooley_tukey(x, n, flag, n2); /* FFT in x */
}