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)

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

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?
> 
> 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

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.