5 Nov
2003
5 Nov
'03
7:27 a.m.
Erik de Castro Lopo wrote:
On Wed, 5 Nov 2003 10:54:58 +0100 (CET)
Tim Goetze <tim(a)quitte.de> wrote:
second part of chapter 26, http://dspguide.com/ has the algorithm.
takes some fiddling for every filter you use it for, but it usually
is worth the effort.
i have a python implementation of the algorithm if you like that
better than BASIC (FFT and IIR work is done in a largish, somewhat
unpolished and unreleased-yet c++ lib of mine).
tim
i feel the need to clarify/correct myself: the
filters employed are
not chebyshev designs, they were designed the same way as 'unmatched':
frequency response given, iteratively approximate the filter.
they do a lot better than chebys of the same order, but it's quite
impossible to recalculate their coefficients at runtime. if that is
demanded, the polyphase design probably wins easily.
Tim, do you have any more info about this filter design procedure? I've
currently got a nasty filter design problem that I'm looking for a
solution for.