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FFTW (Fastest Fourier Transform in the West) 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).

Versions and Availability

Module Names for fftw on smic
Machine Version Module Name
smic 3.3.3 fftw/3.3.3/INTEL-140-MVAPICH2-2.0
▶ Module FAQ?

The information here is applicable to LSU HPC and LONI systems.


A user may choose between using /bin/bash and /bin/tcsh. Details about each shell follows.


System resource file: /etc/profile

When one access the shell, the following user files are read in if they exist (in order):

  1. ~/.bash_profile (anything sent to STDOUT or STDERR will cause things like rsync to break)
  2. ~/.bashrc (interactive login only)
  3. ~/.profile

When a user logs out of an interactive session, the file ~/.bash_logout is executed if it exists.

The default value of the environmental variable, PATH, is set automatically using SoftEnv. See below for more information.


The file ~/.cshrc is used to customize the user's environment if his login shell is /bin/tcsh.


Modules is a utility which helps users manage the complex business of setting up their shell environment in the face of potentially conflicting application versions and libraries.

Default Setup

When a user logs in, the system looks for a file named .modules in their home directory. This file contains module commands to set up the initial shell environment.

Viewing Available Modules

The command

$ module avail

displays a list of all the modules available. The list will look something like:

--- some stuff deleted ---

---------------- /usr/local/packages/Modules/modulefiles/admin -----------------
EasyBuild/1.11.1       GCC/4.9.0              INTEL-140-MPICH/3.1.1
EasyBuild/1.13.0       INTEL/14.0.2           INTEL-140-MVAPICH2/2.0
--- some stuff deleted ---

The module names take the form appname/version/compiler, providing the application name, the version, and information about how it was compiled (if needed).

Managing Modules

Besides avail, there are other basic module commands to use for manipulating the environment. These include:

add/load mod1 mod2 ... modn . . . Add modules
rm/unload mod1 mod2 ... modn  . . Remove modules
switch/swap mod . . . . . . . . . Switch or swap one module for another
display/show  . . . . . . . . . . List modules loaded in the environment
avail . . . . . . . . . . . . . . List available module names
whatis mod1 mod2 ... modn . . . . Describe listed modules

The -h option to module will list all available commands.

Module is currently available only on SuperMIC.


On SuperMike, Philip abd Eric, softenv defines some variables which point at the library home directory. Use soft-dbq to determine it's name, then use it to add a link option to your build. You may see something like this (the output has been edited for brevity):

$ soft-dbq +fftw-3.3.3-Intel-13.0.0-openmpi-1.6.2

This is all the information associated with
the key or macro +fftw-3.3.3-Intel-13.0.0-openmpi-1.6.2.
. . .
    fftw_HOME = /usr/local/packages/fftw/3.3.3/Intel-13.0.0-openmpi-1.6.2

On SuperMIC and QB-2, module defines the variables. Use module show to show the names.

$ module show fftw/3.3.3/INTEL-140-MVAPICH2-2.0
setenv LHPC_ROOTFFTW /usr/local/packages/fftw/3.3.3/INTEL-140-MVAPICH2-2.0 

The compile and build options to use would be:

       -L${fftw_HOME}/lib -lname


       -L${LHPC_ROOTFFTW}/lib -lname

The include files to use, and the library name depend on features needed. For more information, please refer to the materials in the Resources section.


Last modified: August 22 2017 15:10:53.