FFTW stands for Fastest Fourier Transform in the West. 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). To build FFTW, you will need to download the source, build it with the suggested flags, and install it. These steps, and any known limitations, are described in the sections below.
Download: FFTW (version 2.1.5).
In brief, the following steps are sufficient to build Namd and its dependent applications from the command line:
Part 1, fftw:
>mkdir ~/fftw >cd ~/fftw >mkdir src >cd src
copy the tar file to this directory, then proceed with the following on the command line:
>tar -xvjf fftw-3.1.3.tar.bz2 >cd fftw-3.1.3 >export CC=opencc F77=openf90 CFLAGS=-O3 FFLAGS=-O3 >export MY_FFTW_PATH=~/fftw >./configure --enable-float --enable-type-prefix --enable-static \ --prefix=$MY_FFTW_PATH >make >make install
There are no known limitations.