fftw_low.c File Reference

#include <config.h>
#include <fortran_types.h>

Include dependency graph for fftw_low.c:

Functions
void	fft_optimize (int *n, int par)
void	FC_FUNC_ (oct_fft_optimize, OCT_FFT_OPTIMIZE)

Function Documentation

fft_optimize()

void fft_optimize	(	int *	n,
		int	par
	)

Optimizes the order of the FFT grid. The best FFT grid dimensions are given by 2^a*3^b*5^c*7^d*11^e*13^f where a,b,c,d are arbitrary and e,f are 0 or 1. (http://www.fftw.org/doc/Complex-DFTs.html) par is the parity: the result must satisfy n % 2 == par, provided par >= 0.

NTD: To make cufft and FFTW to always give the same results, the multiples of 11 and 13 are not allowed.

FC_FUNC_()

void FC_FUNC_	(	oct_fft_optimize	,
		OCT_FFT_OPTIMIZE
	)