FFTW on Debian Squeeze (AMD64)

Installing from Debian Repository

$ sudo aptitude install libfftw3-3 libfftw3-dev

The second package is only necessary for development.

Installing from Source

The version of FFTW I use here is 3.2.2.  Follow this:

$ mkdir tmp
$ cd tmp
$ wget http://www.fftw.org/fftw-3.2.2.tar.gz
$ tar -xvzf fftw-3.2.2.tar.gz
$ cd fftw-3.2.2
$ ./configure --prefix=/usr/local/fftw-3.2.2 --enable-threads \
    --enable-single F77=gfortran
$ make
$ sudo make install
$ sudo ln -s /usr/local/fftw-3.2.2 /usr/local/fftw

This will install FFTW under /usr/local/fftw-3.2.2, symlinked by /usr/local/fftw as well.

Note that the portion in red at the configure line should be modified accordingly.  I use GFortran, hence the F77 option.  One of the programs that I often ends up building need both double and single precision versions of FFTW, so I run ./configure ; make ; make install once with --enable-single and another without the --enable-single option.  This will install both versions under the same lib directory.