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jfftw: Java FFTW Interface

jfftw is a simple, and partial, Java interface to the highly optimised FFTW C-package from Matteo Frigo and Steven Johnson from the Department of Applied Mathematics, MIT.

This package uses the Java jni interface and must have the both the native FFTW3 library and the local native sharable JFFTW in place.

Local use in School of Physics:
This package is installed on the local Linux system but to pickup the native library you must set the environmental variable LD_LIBRARY_PATH, so in bash speak, either type, or add to your .bash_profile:

export LD_LIBRARY_PATH=/ifp/java/lib

This package has two levels of use, one using the DataArray classes which also handles the data, and the lower level FFTW classes which just takes raw FFTs, these are outlined below:

There is also a Package Document in PDF with extra FFT detail and the Class JavaDoc.

If you are external, or want it on your own machine you can Download Package.

Plans and Efficiency

At the moment this package make a new plan for every FFT it takes so DOES NOT make best use of FFTW high level of optimisation. Its currently designed to make it as easy as possible to take FFT without having to worry about plans, wisdom etc. This is OK for people who want to take ``a few'' FFT, but not ideal for people wanting to take many FFT of the same size (for example for a real-time spectrum analyser). I am working on an updates FFTEngine interface that addresses this problem; more on this later.

Change Log

The package is still in fairly raw pre-release form, the recent changes are: