Install FFTW3

Remarks

As usual we would like to install the libraries in the user space, so we will create a couple of directories for that purpose:

 mkdir $HOME/usr
 mkdir $HOME/soft

To install FFTW3, download the package from the FFTW3 download page and decompress it:

 cd ~/soft
 wget http://www.fftw.org/fftw-3.3alpha1.tar.gz
 tar -zxvf fftw-3.3alpha1.tar.gz
 cd fftw-3.3alpha1

Ubuntu only: If you want to install FFTW3 in your local Ubuntu you can skip this tutorial altogether and just run:

 sudo apt-get install libfftw3-dev libfftw3-doc

However the MPI version (e.g. for testing) will not be installed in this way.

Build and Install (serial version only)

Then configure, make and install:

 ./configure --prefix=$HOME/usr
 make
 make install

The following files will be installed in:

 ~/usr/include/fftw3.h
 ~/usr/include/fftw3.f
 ~/usr/lib/libfftw3.a
 ~/usr/lib/libfftw3.la

The typical compilation options will be

 export LD_RUN_PATH=$HOME/usr/lib  #do this once *before* compiling
 cc -I$HOME/usr/include program.c -L$HOME/usr/lib -lfftw3 -o program

The official tutorial on the usage of FFTW3 (which is different from FFTW 2) is located here.

MPI version

To install the experimental MPI version of FFTW3, make sure you downloaded fftw-3.3alpha1 (and not fftw-3.2 for example). Also make sure that there is an MPI compiler available:

 $which mpicc
 /usr/bin/mpicc

If it is not available, you can choose one with the command 'mpi-selector-menu' in wcr. I tested this with the 'openmpi_gcc-1.2.2' compiler.

Do the same procedure of downloading the file and decompressing it, but add the --enable-mpi flag:

 ./configure --prefix=$HOME/usr --enable-mpi
 make install

now the library will be installed in your home directory, besides the files mentioned above, you will find also:

 ~/usr/include/fftw3-mpi.h
 ~/usr/lib/libfftw3_mpi.a
 ~/usr/lib/libfftw3_mpi.la

The typical command line for compilation will be

 export LD_RUN_PATH=$HOME/usr/lib #do this *before* compiling
 mpicc -I$HOME/usr mpi_program.c -L$HOME/usr/lib -lfftw3_mpi -lfftw3 -o mpi_program

Make sure to link *first* to fftw3_mpi and *later* to fftw3.

The official tutorial for the MPI version of FFTW3 can be found here.