[R] how to write symbol (nabla) in R graph
Prof Brian Ripley
ripley at stats.ox.ac.uk
Fri Jun 20 10:12:17 CEST 2008
On Fri, 20 Jun 2008, Dieter Menne wrote:
> Nuno Prista <nmprista <at> fc.ul.pt> writes:
>> Can anyone of you tell me how to write a "nabla" symbol in an R graph?
We need to know what is meant by 'nabla':
http://en.wikipedia.org/wiki/Nabla_symbol tries to disambiguate.
> I have not tested it,
so others are left to find your errors for you.
> but according to
> nabla is Unicode 
U+0321 is COMBINING PALATALIZED HOOK BELOW ! You have misread that
document, which is about Hershey encodings not Unicode.
> Check documentation on plothmath how to use it.
Perhaps you meant ?Hershey ?
> Note: the documents cited in plotmath are huge, and it would be nice to have
> something like the gnu-reference I google for a short list.
Like the reference
? The Gnuplot reference you cite does qualify as 'huge' and you have
demonstrated how unclear it is. ?plotmath has both the definitive
documentation and a reference to a short table (added by Paul Murrell at
Steve Ellison's answer is Unicode U+2207 via the symbol font. That is
'Nabla' (capitalized) according to
although the Adobe glyph name is 'gradient'.
To summarize, do one of
Use \xd1 in font = 5
Use plotmath with symbol("\xd1") (or equivalent)
Use "\u2207" on systems that support UTF-8 (and with a font and graphics
device that supports this).
text(1,1, "\xd1", font=5)
Depending on the locale and graphics device (and version of R) each of
these may or may not work -- the first is probably the most reliable.
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
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