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Student Support Forum: 'Discrete Fourier Trafo of numeric solution' topicStudent Support Forum > General > "Discrete Fourier Trafo of numeric solution"

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Gotthold Flaeschner
11/02/12 05:21am

Hi there,

I calculated a numerical solution (by Runge Kutta) of an oszillation with a final time t and n steps in between.

Now if i plot the solution in position space it works fine, if n>>t. But in this case the DFT looks really strange (see attachement).

If n~t, the frequency space looks good or at least I can see a lorenzian shape somewhere not near bin 0 or bin n, but the resolution is too bad in the position space. Why does the DFT behave this way? Is it already a uncertainty principle or can I fix it somehow?

Thank you so much!

Attachment: n=1000 t= 10 Fourier.png, URL: ,

Subject (listing for 'Discrete Fourier Trafo of numeric solution')
Author Date Posted
Discrete Fourier Trafo of numeric solution Gotthold Fla... 11/02/12 05:21am
Re: Discrete Fourier Trafo of numeric solution Bill Simpson 11/03/12 1:26pm
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