Can you trim a FFT?

From: shoo <JGBurgess@xxxxxxxxx>
Date: Mon, 19 May 2008 03:52:33 -0700 (PDT)

Hey all,

I will try to explain what i am after...

discrete signal -> window -> FFT on window -> display spectrum .move
on and repeat. (a STFT is not what im after)

When I am displaying the specturm I only want the 5Hz-30Hz range
displyed.

Currently I am doing a FFT then taking out the 5-30Hz and displaying.

I would nievily like to know if there is a method of applying the fft
with the intention of only requiring a predetermind range of
frequency. hense no waste in the fft.

I am reading up a fair bit on ffts however Ive had no luck so far.
Thanks for any help.
Jon
.

Follow-Ups:
- Re: Can you trim a FFT?
  - From: Steven G. Johnson
- Re: Can you trim a FFT?
  - From: John Bailey
- Re: Can you trim a FFT?
  - From: Tim Little

Prev by Date: derivitives of complex function
Next by Date: Re: derivitives of complex function
Previous by thread: derivitives of complex function
Next by thread: Re: Can you trim a FFT?
Index(es):
- Date
- Thread

Relevant Pages

Re: fft
... displaying Logo.another one for display the FFT. ... run my GUI the logo will get displayed.now my problem is ... displaying logo,but not displaying on the axes for fft.i ...
(comp.soft-sys.matlab)
Re: Controls Not updating
... > I am doing an FFT and displaying the results. ... calculating then you need to move the calculating into a secondary ... Start by putting the calculation in a static function and ...
(microsoft.public.vc.mfc)
Controls Not updating
... I am doing an FFT and displaying the results. ... the controls/Views are not updating/repainting. ... I suppose I am missing the update messages, but I don't know how to fix it. ...
(microsoft.public.vc.mfc)
Re: Can you trim a FFT?
... hense no waste in the fft. ... spectrum needs only O. ... Try a search on the "Lomb-Scargle Periodogram", ...
(sci.math)