[Rd] unexpected behaviour of expression(sum())

[Prof Brian Ripley]

So my guess on scalable fonts was right.

I suspect this is a problem in how the X server is using Type1 fonts, 
specifically in how it thinks they are encoded.  This is why I asked about 
the locale: \summation is \345 in the Adobe symbol character set and 
\circleplus is \305 which is a u/case to l/case difference in Latin-1.

I now recall Kurt had similar problems with gsfonts-x11 last August:

>> Kurt has found a problem with the last two pages of demo(plotmath) on
>> X11 (some symbols either wrong or missing completely).

We found

>> the issue seems to be that gsfonts-x11 has aliases
>>
>> -adobe-symbol-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific 
"-urw-standard symbols l-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific"
>> "-urw-standard symbols l-regular-r-normal--0-0-0-0-p-0-adobe-fontspecific" "-
urw-standard symbols l-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific"

>> Any way to ensure that these fonts are not taken by us?

> I don't think so, for if I understand that the alias file is lying about
> encodings. We specifically added "-adobe-symbol" to overcome problems with
> abi symbol fonts at ETHZ, but if that package says the urw fonts in
> `standard symbols l' are in adobe symbol and they are not, you are in
> trouble.

Brian


On Sat, 12 Mar 2005, Deepayan Sarkar wrote:

> On Friday 11 March 2005 13:13, Marc Schwartz wrote:
>> On Fri, 2005-03-11 at 17:17 +0000, Prof Brian Ripley wrote:
>>> I see you have both a scalable font (the first) and size-specfic
>>> fonts. My guess is that the scalable font is not encoded in the
>>> same way as the others: can you track down where it is coming from?
>>>
>>> Otherwise my list on FC3 is the same as yours (minus the
>>> duplicates, which are also puzzling).  I have also just checked
>>> Exceed, which has the same list plus scalable fonts (and also has
>>>
>>> -adobe-symbol-0-0-normal--0-0-0-0-p-0-adobe-fontspecific
>>> -adobe-symbol-0-0-normal--0-0-0-0-p-0-sun-fontspecific
>>> -adobe-symbol-0-0-normal--0-0-100-100-p-0-adobe-fontspecific
>>> -adobe-symbol-0-0-normal--0-0-100-100-p-0-sun-fontspecific
>>> -adobe-symbol-0-0-normal--0-0-75-75-p-0-adobe-fontspecific
>>> -adobe-symbol-0-0-normal--0-0-75-75-p-0-sun-fontspecific
>>>
>>> which caused problems for 2.0.1 with getting bold symbols in some
>>> sizes, hence the second bug fix I mentioned).
>>>
>>> As a wild guess, do you have a font server as well as local fonts?
>
> I don't think so. My XF86Config-4 file has the line
>        FontPath        "unix/:7100"      # local font server
> but I don't see any font server package actually installed, and I get
>
> deepayan $ xfsinfo -server localhost:7100
> xfsinfo:  unable to open server "localhost:7100"
>
> . I do have fontconfig (and a bunch of fonts all over the place), which
> may explain the duplicates.
>
> [...]
>
>> Deepayan, which X server is being used? FC3 (fully updated) is using
>> xorg 6.8.1 if that might make a difference.
>
> I'm using Debian testing, the version of X being 4.3.0.dfsg.1-10 (4.3.0
> with some modifications). But this is not the issue, since things work
> fine on another Debian system with the same version of X. It turns out
> that the problem is with the gsfonts-x11 package. After removing it, I
> get the correct symbols (with a warning message):
>
>> expr = expression(sum(x, 1, n))
>> plot(1, main = expr, type = "n")
>> text(1, 1, expr)
> Warning message:
> X11 used font size 8 when 9 was requested
>
>
> There's still a bug, but probably not in R. The only external indication
> I can get that something is wrong is when I compare
>
> $ xfd -fn
> -adobe-symbol-medium-r-normal--20-140-100-100-p-107-adobe-fontspecific
>
> and
>
> $ xfd -fn
> -adobe-symbol-medium-r-normal--0-0-100-100-p-107-adobe-fontspecific
>
> The second one claims to display
>
> -urw-standard symbols
> l-medium-r-normal--17-120-100-100-p-89-adobe-fontspecific
>
> and in fact does *not* have the summation symbol. (Screenshots at
>
> http://www.stat.wisc.edu/~deepayan/R/xfd-fixed.png and
> http://www.stat.wisc.edu/~deepayan/R/xfd-scalable.png
>
> ). However, the file /usr/X11R6/lib/X11/fonts/Type1/fonts.dir has the
> line
>
> s050000l.pfb -urw-standard symbols
> l-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific
>
> which suggests that the actual font used is s050000l.pfb, and a font
> editor shows that it does contain the summation symbol (U+2211).
>
> Deepayan
>
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
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