How to show biquad frequency response with logarithmic scales in Octave?

Hi,

I'm new to Matlab/Octave and I need a simple frequency response plot. I
googled freqz & plot, but it shows the frequency on linear scale, for
audio, which is my case, it is much more suitable to watch logarithmic
scale. How to do that?

Thanks.
jungledmnc

On Mon, 14 Nov 2011 12:31:10 -0600, jungledmnc wrote:

> Hi,
> 
> I'm new to Matlab/Octave and I need a simple frequency response plot. I
> googled freqz & plot, but it shows the frequency on linear scale, for
> audio, which is my case, it is much more suitable to watch logarithmic
> scale. How to do that?

I assume you already have a transfer function in the z domain?

Search the help files for "bode".  I'm not sure how one does that in 
Octave (apropos?), but I'm almost certain that it'll cough up a Bode plot 
function name.

Chances are high that you can just type "help bode" and get what you want.

-- 
www.wescottdesign.com

In Matlab it's "semilogx()", "semilogy()", and "loglog()". I've never used
Octave, but I suspect that it's compatible.

Greg