We shall first consider plotting simple graphs showing the dependence
of one variable upon another. Such a graph may be composed of several
elements:
- A box which defines the ranges of the variables, perhaps with axes
and numeric labels along its edges,
- A set of points or lines within the box showing the functional
dependence,
- A set of labels for the variables and a title for the graph.
In order to draw such a graph, it is necessary to call at least four of
the PLPLOT functions:
- <#218#>plstar<#218#>, to specify the device you want to plot on,
- <#219#>plenv<#219#>, to define the range and scale of the graph, and
draw labels, axes, etc.,
- One or more calls to <#220#>plline<#220#> or <#221#>plpoin<#221#> to draw
lines or points as needed. Other more complex routines include
<#222#>plbin<#222#> and <#223#>plhist<#223#> to draw histograms, <#224#>plerrx<#224#> and
<#225#>plerry<#225#> to draw error-bars,
- <#227#>plend<#227#>, 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 #draw#229> above. The routine
<#230#>plstar<#230#> needs to be called only once, unless a different output device
is required.