[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: problem with the bode function
From: |
Lukas Reichlin |
Subject: |
Re: problem with the bode function |
Date: |
Wed, 7 Dec 2011 15:42:45 +0100 |
On 07.12.2011, at 14:11, Laurent Tissier wrote:
> Hello,
>
> yesterday I have updated the control toolbox (ver 2.2.2) and now the
> following command fails:
>
> H=tf([1 0 1],[1 1 1]);
> bode(H)
>
> I work under ubuntu 10.10 with octave 3.4.
Thanks for your report. A few observations:
- The problem is also present with control-2.2.1. --> not related to version
2.2.2
- [mag, pha, w] = bode (H) doesn't hang ---> looks like a plotting problem
- both Fltk and Gnuplot graphics backends are affected
- H=tf([1 1 1],[1 1 1]) gets plotted ---> The zero for s^1 in the numerator
seems to cause the problem
- H = tf (1, [1, 0, 1]) hangs too ---> there must be a problem with complex
conjugate pole or zero pairs when their real part is 0.
- Plotting mag, pha and w from point 2 works ---> hmm…
- Commenting out the two 'axis' commands in bode.m gets your example working
- The variable ax_vec_mag contains infs and nans when octave hangs --> I'll
take care of __axis_limits__.m
I'll try to fix this and release control-2.2.3.
Regards,
Lukas