**GNU Emacs Calc 2.02 Manual**

# 14. Graphics

The commands for graphing data begin with the `g` prefix key. Calc
uses GNUPLOT 2.0 or 3.0 to do graphics. These commands will only work
if GNUPLOT is available on your system. (While GNUPLOT sounds like
a relative of GNU Emacs, it is actually completely unrelated.
However, it is free software and can be obtained from the Free
Software Foundation's machine ``prep.ai.mit.edu'`.)

If you have GNUPLOT installed on your system but Calc is unable to
find it, you may need to set the `calc-gnuplot-name`

variable
in your ``.emacs'` file. You may also need to set some Lisp
variables to show Calc how to run GNUPLOT on your system; these
are described under `g D` and `g O` below. If you are
using the X window system, Calc will configure GNUPLOT for you
automatically. If you have GNUPLOT 3.0 and you are not using X,
Calc will configure GNUPLOT to display graphs using simple character
graphics that will work on any terminal.