The FFTW (The Fastest Fourier Transform in the West) is a 'C' subroutine library for computing the Discrete Fourier Transform in one or more dimensions, of both real and complex data, and of arbitrary input size. The FFTW package was developed at MIT by Matteo Frigo and Steven G. Johnson. They believe that " FFTW's performance is typically superior to that of other publicly available FFT software. Moreover, FFTW's performance is portable: the program will perform well on most architectures without modification."
FFTW is 'free open source software' distributed under the GNU General Public License.
FFTW version 3.2.1 is now used within default versions of SPIDER on Linux and OSX for calculating Fourier transforms. Note: FFTW 2 is still used within SPIDER for MPI.
Since SPIDER is now distributed under the GPL license we can now include statically linked FFTW libraries within our SPIDER distribution. Unless you wish to recompile/relink SPIDER you do not have to install FFTW and can ignore the rest of the information on this page.
FFTW3 code is accessed by defining the preprocessor variable: SP_LIBFFTW3 when compiling and linking SPIDER. See: Makefile_linux_mp_opt64 for example of how this is done.
The SPIDER distribution contains three sets of FFTW object code libraries for use with different platforms:
The spider executables included with your distribution have been statically linked with the respective libraries for these platforms. fftw3-intel/libfftw3-intel64-icc/lib, fftw3-opt64/lib,
If you wish to recompile FFTW-3.2.1: