PLPLOT can draw graphs consisting of points with optional error bars,
line segments or histograms. Functions which perform each of these
actions may be called after setting up the plotting environment
using <#295#>plenv<#295#>. All of the following functions draw within the box
defined by <#296#>plenv<#296#>, and any lines crossing the boundary are clipped.
Functions are also provided for drawing surface and contour representations
of multi-dimensional functions. These are described in
Chapter #advanced#297>