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From: "Oscar " <oscarodrigo3k@yahoo.es>
Newsgroups: comp.soft-sys.matlab
Subject: Re: About FFT and Even Function
Date: Sun, 1 Nov 2009 16:58:01 +0000 (UTC)
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dbd <dbd@ieee.org> wrote in message <a220a52b-a008-4b16-acc7-0656a03275b3@w37g2000prg.googlegroups.com>...
> On Oct 31, 11:11 pm, "Nasser M. Abbasi" <n...@12000.org> wrote:
> > ...
> > If the data sequence itself is real and even (i.e. x[n]=x[N-n]) where N is
> > ...
> > --Nasser
> 
> Let's try that:
> 
> >> % Nassar's formula, N = 6, x[n] = x[N-n] for n=1:N-1
> >> fft([1 2 3 2 1 0])'
> ans =
>    9.0000
>   -2.0000 + 3.4641i
>         0
>    1.0000
>         0
>   -2.0000 - 3.4641i
> >> % "FFT-even" version,  N = 6, x[n] = x[N-n+1] for n=2:N
> >> fft([0 1 2 3 2 1])'
> ans =
>      9
>     -4
>      0
>     -1
>      0
>     -4
> >>
> 
> Dale B. Dalrymple


ohhh!! Thank you for your help!!!!, :)