[R] undesired grid in ps/eps outputs generated by filled.contour or image

Marc Schwartz marc_schwartz at comcast.net
Fri Feb 6 21:08:25 CET 2009

on 02/06/2009 01:32 PM Rachel Albrecht wrote:
> Hi!
> Whenever I save a graphic in ps/eps format generated by filled.contour or
> image, an undesired grid is added to it (not visible on the X11 screen). For
> example:
> postscript("volcano.eps")
> filled.contour(volcano,col=gray(seq(0,1,,50)),levels=seq(min(volcano),max(volcano),,50))
> dev.off()
> Any ideia how to eliminate this grid?
> Thanks,
> Rachel

I can confirm the problem, running:

  R version 2.8.1 Patched (2009-01-24 r47726)

on Fedora 10.

The problem is actually worse if using the pdf() device, with additional
artifacts present.

There was a posting about this back in 2003:


with no replies. There is a bug report here from 2004:


that seems to be related. So it seems the issue has been around for a while.

I tried increasing the granularity of the color scale, though without
any benefit.

Will have to defer to the graphics device wizaRds on this one.

Marc Schwartz

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