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From:  dspguy2@netscape.net
Newsgroups: comp.dsp,comp.soft-sys.matlab
Subject: Re: how to use IFFT to reconstruct signal in a specific region t in [a, b]?
Date: Fri, 10 Aug 2007 06:24:24 -0700
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On Aug 9, 12:19 am, "Luna Moon" <lunamoonm...@gmail.com> wrote:
> Hi all,
>
> Let's say by doing IFFT on F(v), which is the spectrum of signal f(t), I was
> able to reconstruct f(t), for t in [0, T].
>
> Now I want to ask is there a way to do another IFFT to reconstruct the
> specific part f(t) for t in [T, 2T], without any waste of previous
> calculations?
>
> Basically, I want to ask, if it is possible to use IFFT to reconstruct to
> any slot t in [a, b] in the time domain for signal f(t)?
>
> Thanks a lot!

You can use Chirp Z Transform methods to evaluate portions of either
the frequency or time domain. The CZT is discussed in the O&S books.

Cheers,
David