06.02.2009 23:00

I have students version of Matlab (release 2007a) running on my laptop. It is actually the only piece of non-free software that I run. And indeed, I find their licence/company policy embarrassing. And it's plain expensive, only those students licences are cheap (ca. 70 Euros...) But still so it's a bad deal, because they are normally out-of-date releases and quite buggy. In my case I had no way to get certain frequently used characters like "^" (exponentiation) and "~" (negation) printed unless I switched to an American keyboard layout. But me, I don't now by heart where all the special characters are. So using the American layout worked but caused a lot of typos and wild character binding guessing. Not very comfortable. And then whenever I tried to edit certain features in the preferences the whole thing crashed. Until I noticed from the lots of JAVA exceptions that Matlab uses its own JRE. So I changed it to my newer Java version.
Now it works beautifully, I can browse the prefs without crashes, and I even get the "^"s and "~"s where they should be. But hey, if you ship a JRE with your program, why don't you check it's together working beforehand? It's a bit embarrassing, no?
So here is what I did:

How to change Matlabs Java version

By default Matlab ships with its one JRE, which is in (for linux 32bit)
$MATLABHOME/sys/java/jre/glnx86/jre_xx
where $MATLABHOME is your installation directory and xx stands for the Java version. In my case (release 2007a) it's Java 5. I created a link in this directory
$ cd $MATLABHOME/sys/java/jre/glnx86
$ ln -x /usr/lib/jvm/java-6-sun/jre jre1.6
Then I edited the file jre.cfg in the same directory to contain this link instead of the old version. But this is not enough. You have to set the environment variable MATLAB_JAVA. So I added the line
export MATLAB_JAVA=/usr/lib/jvm/java-6-sun/jre
in my .bashrc then open a new shell and start Matlab from it. Note that for me java-6-openjdk did not it crashed right after startup.

You might ask why I you have this "evil" software in the first place? Right. I know there is Octave to replace it, and I use that as well. The reason why I still have Matlab is that we teach courses in the Master's programme in Matlab. Oh, well this is even worse. We hook the student on to it... I totally agree, we should migrate all the material to Octave or even C (which the students are more at ease with anyway, they normally don't manage to get into the matrix/vector programming model of Octave/Matlab), but that is out of my hands.
I even had to buy the student licence for my laptop because there was no other way that I could show the programs in class.
(No, there is no University owned laptop that I could use. And no, the computers in the lab cannot be used with a projector, and no I could not login to a remote computer and run it there, because there was no network plug with a DHCP service in the computer lab at that time. I have tried it all. Uff, you are free to imagine by yourself, what I my opinion is about all this...)