mpoint(...,cpch,add=FALSE,type="p")add is TRUE then overlay on an existing plottype="p", lines if type="l"mpoint enables several point or polygon datasets to be overlayed. The plot
region is calculated so that all the specified datasets fit in the region.
The parameter cpch specifies the characters to use for each set of points. The
default cpch consists of the numbers 1 to 9 followed by the uppercase
letters A to Z. If cpch is shorter than the number of point sets to
plot, then it is repeated.pointmap