Gnuplot for the Calculus Instructor

Author: Clinton P. Curry <clintonc@clintoncurry.net>
Homepage:http://www.clintoncurry.net/
Date: Fri Dec 3 22:01:48 UTC 2010

It has been claimed by many that Gnuplot is not suitable for graphs which are destined for publication. However, it is a wonderful tool for quickly and easily getting graphs of functions, for example to use in a calculus lecture. Here are a few tips for making graphs which will help you convey concepts to calculus students.

Axes

In most text books, the x- and y-axes play an important role in graphing. Indeed, every graph includes them, whereas the default Gnuplot graph instead opts for a rectangular grid with the edges labeled. This can throw off some students. You can use the following incantation to make the graphs look a bit more "standard".

set border 0
set xzeroaxis lt -1
set yzeroaxis lt -1
set xtics axis
set ytics axis

Labels

The computer-ese appearance of the legend can be a bit disconcerting for a student. Luckily, most terminals seem to support an "enhanced" option; for example, you can use set term wxt enhanced to allow some special features. Then issuing the command

plot sin(x)**2 ti "sin^2(x)"

gives a much friendlier appearance.

Wxt terminal features

Ever try pressing "R" in the graph window?