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From: Greg Heath <heath@alumni.brown.edu>
Newsgroups: comp.soft-sys.matlab
Subject: Re: fft sign?
Date: Sun, 4 May 2008 06:18:41 -0700 (PDT)
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On Apr 29, 11:57=A0am, "h xu" <quabla...@gmx.de> wrote:
> i've written a small and simple script to test the
> fft-function of matlab that transformates exp(i*n*pi/xmax *
> x) from xmin=3D-xmax to xmax. that should result in a
> kronecker delta with positive amplitude with value 1... but
> for some reason the amplitude is negative for odd n,... why
> is that?
>
> xmin=3D-5;
> xmax =3D 5;
>
> N=3D 2^8;
> dx =3D (xmax-xmin)/N;

dx =3D (xmax-xmin)/(N-1)
x   =3D xmin + dx*(0:N-1);

Hope this helps.

Greg