From help-request at octave dot org Sat Apr 8 22:08:46 2006 Subject: Re: impulse invariance question From: Doug Stewart To: help at octave dot org CC: help at octave dot org Date: Sat, 08 Apr 2006 22:06:01 -0500 I made the statement below that all the infinite Laplace zeros are mapped to Z=-1 I now see that C2D maps all but 1 of these zeros to Z=-1. I then did a google search for "matched pole zero" and found that both methods are used!!!!!!????? I have a Text book that says all should be mapped to Z=-1. So my question is: What is the correct way???? Doug Stewart Doug Stewart wrote: > Ronald Crummett wrote: > >> Hi - >> Does anyone know of an impulse invariance function for Octave, similar >> to impinvar in Matlab? I've been trying to write one but if someone has >> already done so, or has any pointers, that would be sweet. >> >> -Ron >> >> >> > Did you look at C2D It has a matched pole zero option. > > As I understand it the impinvariant filter is almost the same as the > Matched pole zero filter. > The matched pole zero has some added zeroes to make the number of > zeroes equal the number of poles. > These extra zeros at placed at -1 in the Zed plane. > > You could start with C2D and add impulse invariant to it. > > If you want help or can't do it I will do it for you and the group. > > Doug Stewart > > ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html -------------------------------------------------------------