Maybe coyote is wanting hardcopy-quality output. Much as I like GD, sometimes you can beat good old EPS for quality graphics.

There is a gnuplot module for Perl, but it looks like it only wants to talk bitmap output. You could always pipe your output into gnuplot, if it's up to the task in question.

I have also seen absurdly complex graphs generated on the fly in pic, the troff-era interpreted graphics language, but that way madness lies.

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bowling trophy thieves, die!