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FFT in MATLAB, do they use radix 2 or radix 4 algorithm>

Started by A.E lover May 11, 2007
HI all,

do yo know what algorithm does MATLAB's fft function based on? I read
from MATLAB's help, it is something called FFTW. Is it a radix 2 or
radix 4 or anything else?

Thank you.

A.E lover wrote:
> HI all, > > do yo know what algorithm does MATLAB's fft function based on? I read > from MATLAB's help, it is something called FFTW. Is it a radix 2 or > radix 4 or anything else? > > Thank you. >
fftw is open-source, you should be able to find that info in a web search (or look at the code...) -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/ Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html
Aloha,

A.E lover wrote:

> do yo know what algorithm does MATLAB's fft function based on? I read > from MATLAB's help, it is something called FFTW. Is it a radix 2 or > radix 4 or anything else?
Read the algorithm part of the documentation (doc fft). The fft decides heuristically which decomposition is used and can use radix 2+4, prime-factor algo. and split-radix algo. Wishing a happy day, LOBI
A.E lover wrote:

> HI all, > > do yo know what algorithm does MATLAB's fft function based on? I read > from MATLAB's help, it is something called FFTW. Is it a radix 2 or > radix 4 or anything else?
Mixed radix (ie neither 2 nor 4). See http://www.fftw.org/ Erik -- ----------------------------------------------------------------- Erik de Castro Lopo ----------------------------------------------------------------- "Working with Perforce in my day job makes me really appreciate just how good GNU Arch is." -- Erik de Castro Lopo
See my answer to the author's duplicate post (grrr) "FFT in Matlab" to
comp.soft-sys.matlab:

http://groups.google.com/group/comp.soft-sys.matlab/msg/b50dd37e0603d326

Regards,
Steven G. Johnson (FFTW co-author)