This script is a close variant of Re^2: [ASCII art graphs] Kisses. It's drawing Lissajous curves in ascii-art.

Sorry for replying so late: since there you say "So here's a perl one, just to disprove blazar's statement" and my statement was that "those [Lissajous figures] would have required either ANSI sequences (and then are nice to be seen while being drawn - I wanted something to paste into email instead) or mangling with a buffer"... I've long wanted to reply: well done! Actually the basics of your approach are easy to understand: instead of drawing implicitly, just do so explicitly, taking slices. Had you asked me in advance wrt Lissajous figures, I would have told: oh yeah, certainly possible - an exercise of masochism, if one exists. But your code contradicts me, since it doesn't seem that overly complex after all. Yet in its minimality, it looks much like a macho algorithm master show off: to work out the details for the uninitiated and the less knowledgeable is certainly possible, but likely to take some time. So why don't you consider expanding it to a full tutorial or something like that? IMHO it will be certainly instructive and Perl is not generally considered for this "kinda stuff", but why not anyway?