null plotting symbol ?
On Tue, 6 May 2003 partha_bagchi at hgsi.com wrote:
pch = 26 seems to produce a blank symbol.
More accurately, it plots nothing. (A `blank' symbol' suggests to me that it plots in the background colour.) That is true *currently* (26-31 are unassigned), but there is no guarantee that will remain so. Why would one use that rather than NA, whose meaning is clear? In brief: what exactly was your point? Were you seriously suggesting using pch=26?
Prof Brian Ripley <ripley at stats.ox.ac.uk>
Sent by: r-help-bounces at stat.math.ethz.ch
05/05/2003 04:39 PM
To: tblackw at umich.edu
cc: r-help at stat.math.ethz.ch
Subject: Re: [R] null plotting symbol ?
NAs in pch cause the corresponding points to be omitted.
On Mon, 5 May 2003 tblackw at umich.edu wrote:
I am calling plot() with argument pch as a vector of numeric symbol codes, the same length as x and y. Is there some code which produces no symbol - a blank - so that I can come back with a second call to points() and fill in these locations using a different fill color and a different symbol size ?
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595