You can take a look at chapter 5 of Graphics Programming with Perl as well as chapter 8 of Mastering Algorithms with Perl. The first will introduce you to GD::Graph, gnuplot and PGPLOT. The second is, as the title implies, a little more involved but provides further examples to try out.

PDL (Perl Data Language) comes with a command line interface and is supposed to be somewhat of a competitor to MATLAB. It may be a bit more than it seems like you're looking for but the documentation is really extensive and apparently includes (just from looking it over a few times) a thorough course.