Chapter 2. Simple Use of PLplot

Table of Contents
Plotting a Simple Graph
Initializing PLplot
Defining Plot Scales and Axes
Labeling the Graph
Drawing the Graph
Finishing Up
In Case of Error

Plotting a Simple Graph

We shall first consider plotting simple graphs showing the dependence of one variable upon another. Such a graph may be composed of several elements:

In order to draw such a graph, it is necessary to call at least four of the PLplot functions:

  1. plinit, to initialize PLplot.

  2. plenv, to define the range and scale of the graph, and draw labels, axes, etc.

  3. One or more calls to plline or plpoin to draw lines or points as needed. Other more complex routines include plbin and plhist to draw histograms, plerrx and plerry to draw error-bars.

  4. plend, to close the plot.

More than one graph can be drawn on a single set of axes by making repeated calls to the routines listed in item 3 above. PLplot only needs to be initialized once unless plotting to multiple output devices.