Publisher review:FFTW is a C subroutine library for computing the discrete Fourier transform (DFT) in one or more dimensions. FFTW is a C subroutine library for computing the discrete Fourier transform (DFT) in one or more dimensions, of arbitrary input size, and of both real and complex data (as well as of even/odd data, i.e. the discrete cosine/sine transforms or DCT/DST). We believe that FFTW, which is free software, should become the FFT library of choice for most applications.
FFTW's performance is typically superior to that of other publicly available FFT software, and is even competitive with vendor-tuned codes.
Features:
- Speed (Supports SSE/SSE2/3dNow!/Altivec, since version 3.0.)
- Both one-dimensional and multi-dimensional transforms.
- Arbitrary-size transforms. (Sizes with small prime factors are best, but FFTW uses O(N log N) algorithms even for prime sizes.)
- Fast transforms of purely real input or output data.
- Transforms of real even/odd data: the discrete cosine transform (DCT) and the discrete sine transform (DST), types I-IV. (Version 3.0 or later.)
- Efficient handling of multiple, strided transforms. (This lets you do things like transform multiple arrays at once, transform one dimension of a multi-dimensional array, or transform one field of a multi-component array.)
- Parallel transforms: parallelized code for platforms withCilk or for machines with some flavor of threads (e.g. POSIX). An MPI version for distributed-memory transforms is also available, currently only as part of FFTW 2.1.5. machines with some flavor of threads (e.g. POSIX). An MPI version for distributed-memory transforms is also available, currently only as part of FFTW 2.1.5.
- Portable to any platform with a C compiler.
- Both C and Fortran interfaces.
FFTW 3.2a is a C/C++ script for File Management scripts design by Matteo Frigo.
It runs on following operating system: Windows / Linux / Mac OS / BSD / Solaris.
FFTW is a C subroutine library for computing the discrete Fourier transform (DFT) in one or more dimensions.
Operating system:Windows / Linux / Mac OS / BSD / Solaris
FFTW 3.2a script details 
