filtering (signal processing)

[William Park]

John Hunter <jdhunter at ace.bsd.uchicago.edu> wrote:
> 
> I need to do some low pass filtering of Numeric arrays, and the simple
> convolutions I am doing with exponential or sinc functions are not
> getting the job done.  I would like to design some more sophisticated
> filters with faster rolloffs, and am looking for a good python package
> compatible with Numeric arrays.

Usual low-pass is done in frequency-domain.  That is, do FFT, attenuate
high frequencies, then do inverse FFT.  However, if you want simple
averaging (ie. polynomial, running), then time-domain makes more sense.  

-- 
William Park, Open Geometry Consulting, <opengeometry at yahoo.ca>
Linux solution for data management and processing.