Free FFT implementations

[Jon Harrop]

Are there any free FFT implementations for .NET that work for arbitrary "n"?

 

[Laura T.]

This zip here
http://www.cs.ucsb.edu/~ckrintz/racelab/PhxCSBenchmarks/SciMark.zip contains
a C# implementation of the standard GSL FFT algorithm (file FFT.cs).
Not the fastest but works.

 

[Jon Harrop]

This zip here
http://www.cs.ucsb.edu/~ckrintz/racelab/PhxCSBenchmarks/SciMark.zip
contains a C# implementation of the standard GSL FFT algorithm (file
FFT.cs). Not the fastest but works.

It doesn't work for arbitrary "n".

Beyond O(n log n) complexity, performance is not important. I just want
anything that works.

 

[sherifffruitfly]

Are there any free FFT implementations for .NET that work for arbitrary "n"?

http://www.fftw.org/

(a) Free.
(b) arbitrary n
(c) FAST
(d) stable

(e) C, not .Net (but are you truly unable to access a C library?)

 

[sherifffruitfly]

http://www.fftw.org/

(a) Free.
(b) arbitrary n
(c) FAST
(d) stable

(e) C, not .Net (but are you truly unable to access a C library?)

Lo and behold - sone enterprising fellow already wrapped it in C#:

http://www.sdss.jhu.edu/~tamas/bytes/fftwcsharp.html

 

[Jon Harrop]

http://www.fftw.org/

(a) Free.
(b) arbitrary n
(c) FAST
(d) stable

(e) C, not .Net (but are you truly unable to access a C library?)

I'm writing F# code anyway, so C# or (good) C makes little difference to me
as they both need wrapping.

I've just written some simple bindings to FFTW from F#. They seem to work ok
but the DLL doesn't contain all of the necessary information, so some magic
numbers are hardcoded (e.g. FFTW_FORWARD etc. are #defines).

This adds Mathematica/Matlab-like Fourier routines to F#, which you can now
use from interactive sessions.

Incidentally, I found a Windows DLL on fftw.org:

http://www.fftw.org/install/windows.html

My concern about FFTW was that they hate MS compilers (too buggy to compile
FFTW with optimisations) and I didn't want to advise my readers to install
Cygwin (they might as well just run Linux) or fork out for a decent
compiler. Having a binary distro for Windows saves this problem.

Thanks very much!

Now for the rest...