plot2d: Old-style 2D Scatter Plot
This section describes a deprecated command.
It still works, but you are advised to use the more capable
plot2d performs two-dimensional scatter plots,
sending the output to a graphical display or writing it to a file
in some vector or bitmapped graphics format.
You need to supply it with values for one or more X and Y datasets,
in terms of table columns, and it will generate a plot with a point
for each row.
There are many options available to configure the detailed appearance
of the plot, but in its simplest form invocation is quite straightforward.
See Section 9 for more discussion on use of the plotting commands.