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FFT example. Help! [message #19894]

Mon, 01 May 2000 00:00

Peter Brooker
Messages: 28
Registered: July 1999

Junior Member

I am trying to understand the FFT routine IDL uses. Part of my problem
is that though I am familiar with Fourier transforms, I am somewhat
unfamiliar with the fast Fourier transform.

Has anybody written a program that works through a known transform using
the FFT procedure? In particular, I want to be able to plot out F(u) vs
u and have it "make sense".

An example of a known transform is

For
f(x) = 1 for -1/2<x<1/2
= 0 else

the Fourier transform F(u) is given by

F(u)=int(f(x)*exp(-j*2*pi*ux)*dx
=[sin(pi*u)]/pi*u

thanks-Peter Brooker

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FFT example. Help!

By: Peter Brooker on Mon, 01 May 2000 00:00

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