[R] image() generates many border lines in pdf, not on screen (quartz) - R 2.9.1 GUI 1.28 Tiger build 32-bit (5444) - OS X 10.5.8

[Uwe Ligges]

Since it looks like nobody answered so far:

Your code is not reproducible, we do not have rfc, y, zVals nor NoCols.

You could also try to place a screenshot somewhere on a webpage 
including the info about the settings of the corresponding viewer.

Best,
Uwe Ligges




Andreas Fischlin wrote:
> Dear all,
> 
> I have invested substantial amount of work in a complicated, yet on 
> screen perfect looking graph that uses image(). Unfortunately saving it 
> as pdf (or quartz.save at high resolution) all generate very disturbing 
> border lines around each small rectangle that image() has drawn. While 
> using Preview it helps to turn off antialiasing to make those faint 
> lines disappear on screen 
> (http://cran.r-project.org/bin/macosx/RMacOSX-FAQ.html#Why-are-there-faint-lines-in-image-plots_003f). 
> However, they are far from faint on pdf (Adobe Reader v9.1.3, regardless 
> of settings) or any other high resolution rendering (printer) and do not 
> disappear, whatever I do. What I encounter is also in quite sharp 
> contrast with all I read on this issue, including R mailing lists (e.g. 
> http://finzi.psych.upenn.edu/R/Rhelp02/archive/30588.html), e.g. if 
> someone claims those lines would not matter and go away when printing. 
> In my case they don't.
> 
> BTW, my image() statement looks like this:
> 
> image(rfc, y, -t(zVals), zlim=c(-noCols-0.5,0.5), col = 
> heat.colors(noCols), axes=F, add=T)
> 
> where z is a 127 x 3 matrix.
> 
> Since I need high resolution variants for final publication I need to 
> know whether it is possible to force image() to give up drawing these 
> borders (I tried already several low level par parameters, all to no 
> avail). On screen everything looks perfect, pdf, clipboard, quartz.save, 
> save all look bad up to inacceptibly bad, especially pdf and any printing!
> 
> Reading all what I could find on this topic, I fear there might even a 
> bug be present in R (R 2.9.1 GUI 1.28 Tiger build 32-bit (5444)). Can 
> anyone offer some insight or even help?
> 
> Thanks.
> 
> Andreas
> 
> 
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