Splits a graphics display into multiple screens for tree-specific functions
that require more than one screen.
USAGE:
tree.screens(figs, screen.arg = 0, ...)
OPTIONAL ARGUMENTS:
figs:
a multiple figure vector like mfrow or mfcol, e.g,
c(n,m), or an N by 4 matrix where N is the number of
screens and each row specifies the position of a screen on
the display; the first two columns specify the left and
right coordinates (in the 0, 1, 0, 1 plane) for the
screens, and the third and fourth columns the bottom and
top coordinates.
screen.arg:
screen to split up. By default it carves up the current
screen, which initially is the entire display (denoted as screen 0).
VALUE:
Called without arguments this function sets up a generic partition
of the graphics area for the tree-specific functions that
require more than one screen.
DETAILS:
See split.screen documentation for
further details.