What version of R, what OS, what version of Acrobat? I don't see this in 2.5.0 on Windows (using Acrobat 7: Acrobat does not exist on Linux, AFAIK). And reading the PDF produced shows no sign of an extra object for the border.
On Fri, 27 Apr 2007, Matthew Neilson wrote: > Hey all, > > I'm trying to create a plot of two semi-transparent regions. The reason they > need to be partially transparent is so that I can see if there's any overlap. > Here's some example code: > > # BEGIN > > pdf(file="test.pdf",version="1.4") > plot(0,0,type="l",ylim=range(-3,3),xlim=range(-1,5)) > polygon(c(0,1,2,3,4,3,2,1,0), c(0,1,2,1,0,-1,-2,-1,0), col=rgb(1,0,0,0.5), > border=NA) > polygon(c(1,2,3,4,5,4,3,2,1), c(0,1,2,1,0,-1,-2,-1,0), col=rgb(0,0,1,0.5), > border=NA) > dev.off() > > # END > > The problem with this is that, despite setting "border = NA", I get a > big white border surrounding each polygon!! Funnily enough, setting the > alpha channel equal to 1 (as opposed to 0.5) *doesn't* give the border, > but an alpha channel of 1 produces an opaque polygon! :S > > I have read the FAQ, and (unfortunately) turning off line-art smoothing > does not give the desired effect. Furthermore, my pdfs print with a > white border surrounding each transparent polygon. > > Now, here comes the really bizarre part. Whilst Adobe Acrobat displays > the unwanted white border, Apple Preview respects the "border=NA" > argument and shows the two diamonds as they are intended. However, > opening up the pdf in Illustrator CS reveals that there is in fact a > transparent (according to Illustrator) border *on top* of each diamond. > Deleting these two borders (one for each polygon) and re-saving the pdf > appears to correct the issue. So the obvious question is: how did the > surrounding borders get there in the first place? A bug in the polygon > function, perhaps? > > Does anyone have any ideas for preventing these unwanted borders around > semi-transparent polygons (without having to resort to Illustrator)? Has > anyone else even come across this problem? > > Many thanks, > > > -Matt > -- Brian D. Ripley, [EMAIL PROTECTED] 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 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.