PyFFTW

pyFFTW is a pythonic wrapper around FFTW 3, the speedy FFT library. The ultimate aim is to present a unified interface for all the possible transforms that FFTW can perform.

Both the complex DFT and the real DFT are supported, as well as on arbitrary axes of abitrary shaped and strided arrays, which makes it almost feature equivalent to standard and real FFT functions of numpy.fft (indeed, it supports the clongdouble dtype which numpy.fft does not).

Wisdom import and export now works fairly reliably.

Operating FFTW in multithreaded mode is supported.

A comprehensive unittest suite can be found with the source on the github repository or with the source distribution on PyPI.

The documentation can be found on github pages, the source is on github and the python package index page is here.

Requirements (i.e. what it was designed for)

• Numpy 1.6
• FFTW 3.2 or higher (lower versions may work)
• Cython 0.15 or higher (though the source release on PyPI loses this dependency)

(install these as much as possible with your preferred package manager).

Installation

We recommend not building from github, but using the release on the python package index with tools such as easy_install or pip:

pip install pyfftw

or:

easy_install pyfftw

Success has been reported on building on Linux, 32-bit Windows and Mac OSX. It doesn't mean it won't work anywhere else, just we don't have any information on it.

64-bit windows is possible but a bit of fiddling is required (see below).

Read on if you do want to build from source...

Building

To build in place:

python cython_setup.py build_ext --inplace

That cythons the python extension and builds it into a shared library which is placed in pyfftw/. The directory can then be treated as a python package.

After you've run cython_setup.py, you then have a normal C extension in the pyfftw directory. Further building can be done with the setup.py script (as is usually the case).

For more ways of building and installing, see the distutils documentation

Platform specific build info

Windows

To build for windows from source, download the fftw dlls for your system and the header file from here (they're in a zip file) and place them in the pyfftw directory. The files are libfftw3-3.dll, libfftw3l-3.dll, libfftw3f-3.dll and libfftw3.h.

The setup scripts are designed for using with MinGW. They don't work as is with MSVC. If you want to build for 64-bit windows, you will have to use MSVC as building python extensions for 64-bit Windows with MinGW is currently badly supported.

Based on unverified feedback from users, the following changes should allow it to work:

1. When you have a cythoned .c file, comment out #include "stdint.h" and #include "complex.h".
2. remove 'm' from the libraries line inside the if get_platform() == 'win32' block in setup.py.
3. If you're building for 64-bit windows, Change get_platform() == 'win32' to get_platform() == 'win-amd64'

Mac OSX

It has been suggested that FFTW should be installed from macports.