Gnuplot is an easy to use two and three dimensional graphing program. Some of its nice features include

- easy generation of postscript.
- support for X11 in Unix versions.
- support for all functions in the Unix math library
- ability to read data files
- support for contout plots
- excellent online help system - just type "help"

The Gnuplot 3.5 binary is located on Superior in
the directory */usr/local/bin*. The distribution is in
*/local/gnuplot*.

The Mac Version is in the *Graphics* subfolder of *Mathlab Fileserver*.

A simple example of plotting two functions of 1 variable is:

set samples 500 plot [x=-.1 : .1 ] [ -.01 : .01 ] x**2*sin(1/x),x**2resulting in

To plot a datafile

set parametric plot "data.dat" with linespointswhere "data.dat" might contain

0 1 1 10 2 45 3 120 4 210 5 252 6 210 7 120 8 45 9 10 10 1giving

To generate postscript:

set output "picture.ps" set term postscript

Surface plotting from a data file can be done by

set parametric splot "data.dat"where "data.dat" contains 3 column data.

The view can be adjusted by

set view 45to rotate by 45 degrees about the x axis, as well as more complicated set view commands.

It is also possible to plot both parametric and non-parametric functions using splot.

Last Update: *June 20, 1996*