Other examples can be found in the FFTW documentation.#include <fftw.h>...{fftw_complex *in, *out; fftw_plan p; ... in = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * N); out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * N); p = fftw_plan_dft_1d(N, in, out, FFTW_FORWARD, FFTW_ESTIMATE); ... fftw_execute(p); /* repeat as needed */ ... fftw_destroy_plan(p); fftw_free(in); fftw_free(out);}

## FFTW

- Details
- Written by Michael McDonald

The "Fastest Fourier Transform in the West" (FFTW) is a C library for computing discrete Fourier transforms (DFT). Note that there are two main versions of FFTW, version 2 and version 3 which are not compatible. The basic usage of FFTW to compute a one-dimensional DFT of size N is simple, and it typically looks something like this code: