[Numpy-discussion] zoom FFT with numpy?

[Nadav Horesh]

A long time ago I translated a free code of chirp z transform (zoom fft)
into python.
Attached here the source and two translations (probably one of the is
right)

  Nadav.

On Wed, 2007-03-14 at 14:02 -0800, Ray S wrote:

> We'd like to do what most call a "zoom FFT"; we only are interested 
> in the frequencies of say, 6kHZ to 9kHz with a given N, and so the 
> computations from DC to 6kHz are wasted CPU time.
> Can this be done without additional numpy pre-filtering computations? 
> 
> If explicit filtering is needed to "baseband" the data, is it worth 
> it? It sounds like we need to generate cosine data once for each band 
> and N, then multiple with the data for each FFT.
> 
> Has anyone coded this up before? I couldn't find any references other 
> than http://www.dsprelated.com/showmessage/38917/1.php
> and http://www.numerix-dsp.com/siglib/examples/test_zft.c (which uses 
> Numerix).
> 
> Ray
> 
> _______________________________________________
> Numpy-discussion mailing list
> Numpy-discussion at scipy.org
> http://projects.scipy.org/mailman/listinfo/numpy-discussion
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20070315/9e042c08/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: czt2.py
Type: text/x-python
Size: 2564 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20070315/9e042c08/attachment.py>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: czt1.py
Type: text/x-python
Size: 3051 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20070315/9e042c08/attachment-0001.py>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: czt.m
Type: text/x-objcsrc
Size: 2545 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20070315/9e042c08/attachment.bin>