Control systems package for GNU Octave

**johnathanmcclure** · January 27th, 2010

I was using GNU Octave today to follow some MATLAB examples given in my university course on control systems.

One of the examples was to input a basic transfer function. When I tried to type in:

Code:

num1=[10]; den1=[1 2 5]; sys1=tf(num1, den1)

An error was returned:

Code:

error: 'tf' undefined near line # column #

I was frustrated because the online manual for Octave seems to clearly describe the "tf" function. Why was the tf function missing?

After searching for a while, I found this mailing list posting, where I discovered the stock installation of Octave in the Ubuntu repositories does not include control system functions.

To get these functions, you have to download and install them from Octave-Forge. There are a number of add-on packages available that are not in the default install.

In this case, I wanted the Controls packge, which is at http://octave.sourceforge.net/control/index.html.

Once I had the .tar.gz I went to the command line and did

Code:

$ sudo octave
octave:1> pkg install /foo/bar/downloadedpackage.tar.gz

The results using Octave as a direct replacement for MATLAB aren't perfect, but it's going much better with the Control package!

**not_a_phd** · January 28th, 2010

Did you try to get them through the Ubuntu repositories first?

I think that the octave-control package is what you were looking for.

**johnathanmcclure** · February 17th, 2010

Originally Posted by not_a_phd

Did you try to get them through the Ubuntu repositories first?

I think that the octave-control package is what you were looking for.

I think I tried to apt-get octave-control. It didn't work on my 8.04 rig or my upgraded 9.10 64bit rig.

You seem to be right, it is in the repositories for 9.10, so I don't know what went on with my PC. And it's also a package for 9.04, so those are theoretically covered too. But it's not a package under 8.04 or 8.10, hmmm.

At least the workaround I describe seems to work on my rigs running 8.04 and 9.10. I guess before trying it it'd be a good idea to attempt

Code: