python
Gnuplot.py is a Python module that interfaces to gnuplot, the popular
plotting program. It allows you to use gnuplot from within Python to
plot arrays of data from memory, data files, or mathematical
functions. If you use Python to perform computations or as `glue' for
numerical programs, you can use this module to plot data on the fly as
they are computed. And the combination with Python makes it is easy to
automate things, including to create crude `animations' by plotting
different datasets one after another.