Problem with colormodel in pdf driver

Try changing the color to "grey".

Despite the help pages saying this:
colormodel
a character string describing the color model: currently allowed values are 
"rgb", "gray" and "cmyk". Defaults to "rgb".

I got the expected behavior by making the "gray" -> "grey" change on my Mac 
OS 10.5.6/R2.8.1 system.

-- 
David Winsemius
On Jan 23, 2009, at 7:21 PM, Luis Torgo wrote:

I'm trying to create figures in PDF that use the 'gray' colormodel instead 
of the default 'RGB' model, by requirements of a publisher.

My problem has to do with the fact that I'm not being able to get gray 
colors with this option on the pdf() driver. Here is a small example for 
problem replication:

R.version

            _                          platform       i486-pc-linux-gnu 
arch           i486                       os             linux-gnu 
system         i486, linux-gnu            status 
major          2                          minor          8.1 
year           2008                       month          12 
day            22                         svn rev        47281 
language       R                          version.string R version 2.8.1 
(2008-12-22)

pdf('exp.pdf',colormodel='gray')
barplot(table(subset(iris,Petal.Width>1)$Species))
dev.off()

Contrary to what I was expecting the bars appear in black and not gray as 
they are supposed to. This is not particularly serious for this toy graph 
but for others it creates more problems.

Interesting enough this problem does not occur with the same option on the 
postscript() driver as it can be observed by running:

postscript('exp.eps',colormodel='gray')
barplot(table(subset(iris,Petal.Width>1)$Species))
dev.off()

Any help is most appreciated.

Luis Torgo

-- 
Luis Torgo
FEP/LIAAD - INESC Porto, LA   Phone : (+351) 22 339 20 93
University of Porto           Fax   : (+351) 22 339 20 99
R. de Ceuta, 118, 6o          email : ltorgo at liaad.up.pt
4050-190 PORTO - PORTUGAL     WWW   : http://www.liaad.up.pt/~ltorgo