
From:  Julius Smith 
Subject:  Re: freqz problems 
Date:  Tue, 4 Oct 2005 11:29:59 0700 
Hello,
I was wondering if this is a known bug. I am running octave version 2.1.50.
In this example, I am computing the frequency response of an FIR filter "h".
octave:96>
octave:96> h=[1, 0.5]
h =
1.00000 0.50000
octave:97> H=freqz(h, 1, 512, "whole");
octave:98> H2=freqz(h, 1, 2*pi*[0:511]/512);
octave:99> norm(HH2)
ans = 27.713
octave:100> norm(abs(H)abs(H2))
ans = 5.3545e15
octave:101>
I would have expected that H = H2, but only their magnitudes are equal. It
turns out that H is the correct answer and H2 is the reponse of a shifter
version of h with h(2) being the sample at the origin and h(1) is the
sampele at time 1.
Thanks,
Raman

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

[Prev in Thread]  Current Thread  [Next in Thread] 