This is the internal function that does the basic plotting of
points and lines. Usually, one should rather use the higher level
functions instead and refer to their help pages for explanation of the
The arguments pch, col, bg, cex,
lwd may be vectors and may be recycled, depending on
type: see points and lines for
specifics. In particular note that lwd is treated as a vector
for points and as a single (first) value for lines.
cex is a numeric factor in addition to par("cex") which
affects symbols and characters as drawn by type"p",
"o", "b" and "c".