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From: "Steven G. Johnson" <stevenj@alum.mit.edu>
Newsgroups: comp.soft-sys.matlab
Subject: Re: FFT acting strangely...
Date: Mon, 3 Mar 2008 08:50:54 -0800 (PST)
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On Mar 3, 11:45 am, "Steven G. Johnson" <stev...@alum.mit.edu> wrote:
> expression in terms of the frequency-domain coefficients is much
> easier to analyze (being a simple sum and not a convolution,

Well, I should correct myself that the DFT can be written as a
convolution, and the direct expression doesn't have any fewer
operations than a convolution, so this isn't realy an advantage of one
expression over the other.  But the fact that the trigonometric-
interpolation viewpoint is in terms of orthogonal functions certainly
makes it easier to analyzer for some purposes, as is the fact that
they are eigenfunctions of differentiation; both of these make it easy
to show which choice of aliasing leads to minimal rms slope, which
seems harder to do in terms of the sinc-convolution picture.