A nice alternative for Matlab would be Octave [1]. However, there is a linux-build for Matlab. This is not free software, however...
Good luck, and if you find some more alternatives...
regards, -sebastiaan
whoops... here's the link: http://www.octave.org
This is another one that I couldn't think of at the time.
Do a bit of googling and you may find what you need.
Where I work, we are looking more and more to open source. It ensures that any work we do will be able to be accessed in the future.
-- Robin Laing