dddima

Like 'git add -p' but much much better:

http://porkrind.org/missives/commit-patch-managing-your-mess...

matplotlib is a library; this is a commandline tool. The Perl part is largely irrelevant.

Got a better one for you: https://github.com/dkogan/feedgnuplot

As the script from the OP, this is a tool to plot STDIN. This one has been refined far more, so it's trivial to use and very powerful.