From ripley@stats.ox.ac.uk  Fri Sep 15 10:23:33 2000
From: ripley@stats.ox.ac.uk (ripley@stats.ox.ac.uk)
Date: Fri, 15 Sep 2000 11:23:33 +0200 (MET DST)
Subject: [Rd] identify.default ignores any setting of cex. (PR#660)
Message-ID: <200009150923.LAA13337@pubhealth.ku.dk>

R 1.1.1 on Windows, but I think this is widespread.

Using either

par(cex=0.5)
plot(1:10)
identify(1:10)

or

plot(1:10)
identify(1:10, cex=0.5)

ignores the cex setting.  The root cause is that par(cex=0.5)
alters cexbase for the device but sets cex=1.0, and the internal
text plotting routines use cex and not cexbase.

The obvious fix is to set cex to cexbase in do_identify. However,
if this is fixed, there is another problem, The offset of the label
is related to the cex in use for the label, and not for the symbol.
So

plot(1:10, type="n")
points(1:10, cex=5)
identify(1:10)

is not sensible in placing the labels.  That may be hard to anticipate,
but 

plot(1:10)
identify(1:10, cex=0.5)

needs to use cex=1 not cex=0.5 for the adjustment.  Perhaps identify is
trying too hard, and should give the user more control over the precise
position of the label (as S-PLUS does).

-- 
Brian D. Ripley,                  ripley@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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


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[Rd] identify.default ignores any setting of cex. (PR#660)
ripley@stats.ox.ac.uk