Gnuplot is a portable multi-platform command-line driven graphing utility. It
was originally created to allow scientists and students to visualize
mathematical functions and data interactively, but has grown to support many
non-interactive uses such as web scripting. It is also used as a plotting engine
by third-party applications like Octave. Gnuplot has been supported and under
active development since 1986.

This port installs extra files for TeX terminals (latex, epslatex, Tikz, etc).

WWW: http://www.gnuplot.info/