[R-SIG-Mac] degree symbol using X11 on OSX
Andy.Jacobson at noaa.gov
Tue May 26 21:33:51 CEST 2009
Using the scheme in plotmath, I can no longer get the degree symbol
for my on-screen plots, using X11 on OS X. I instead see an upper-case
upsilon (I think). This is reproducible using "demo(plotmath)". A
figure drawn with this faulty symbol produces correct postscript (i.e.
with a degree symbol) when I use dev.copy to write it to an eps file.
I'm using R version 2.8.1 Patched (2009-01-19 r47650) on an intel Mac,
fully updated OS X 10.5.7.
Addendum: This question was posed on the R-Help list, and Prof Ripley
was kind enough to give me his thoughts on the problem. His suggested
work-around of X11(type="Xlib") does work. I am re-posting my
original question here at his suggestion. Prof Ripley writes:
> And that's the problem, the fonts used by cairographics on Mac OS X.
> I don't know about the 'no longer': this (and a few others including
> infinity) have been faulty for some time. I think it relates to how
> 'fontconfig' (for which a binary library ships with R for Mac OS X)
> interacts with Mac fonts, but there are many more interesting things
> to do that track down such quirks.
> There are some hints about this on ?X11
> X11 chooses fonts by matching to a pattern, and it is quite
> possible that it will choose a font in the wrong encoding or which
> does not contain glyphs for your language (particularly common in
> 'iso10646-1' fonts).
> This does look very like an incorrect encoding for a symbol font.
> OTOH, the last display in example(points) seems right, so something
> subtle is going on.
> One option is to use X11(type="Xlib"). Another is to use quartz(),
> assuming you are not running R on a remote system.
> This is an Mac-specific question and it is always worth asking such
> on R-sig-mac.
> I believe the behaviour is still the same in 2.9.0 patched, but it
> is always worth checking the current release, especially on
> platforms where components that are otherwise part of the OS ship
> with R (as no one records in the R docs things fixed/broken by
> updates to such components -- we probably don't even know half of
andy.jacobson at noaa.gov
NOAA Earth System Research Lab
Global Monitoring Division
Boulder, Colorado 80305
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