.BG
.VE $Header: /usr3/s/current/s/.help/RCS/rdpen,v 1.2 83/12/30 19:33:14 rab Exp $
.FN rdpen
.TL
rdpen: Get Coordinates from Plot
.CS
rdpen(n, type)
.PP
.AG n
the maximum number of points to identify.  Default is 500.
.AG type
character describing interactive drawing option.
If `type' is "n", nothing is drawn (the default).
Values of "p", "l", "b", and "o" plot points at the digitized
coordinates, lines connecting them, or both points
and lines.
.RT
structure containing vector components `x' and `y' which
give co-ordinates for each point.
The length of these vectors is at most `n',
but can be shorter if the user terminates
graphic input after fewer than `n' points are given.
.PP
See the individual device documentation for the protocol on the
device for identifying points and terminating graphic input.
.EX
# user points at outlier which is then labelled
text(rdpen(1),"outlier") 

lines(rdpen( ))     # input a number of points, connect with line
repen(type="l")    # alternative
.KW plot*
.KW graphic input
.KW iplot*
.WR
