[R] 回复： Italicize Greek symbols in axis

[Bingzhang Chen]

Prof. Ripley,

Thanks. A stupid question: how to find out the codes (e.g.,u03bc)  for the Greek 
letters?

I am trying to italicize the mu in a mathematical expression placed as a label 
for an axis of a graph (but other letters remain plain). I am working on the 
Windows platform. I seem to find out a solution: to copy the µ from the 
character map and use  italic(µ) in the expression.

Bingzhang  



----- 原始邮件 ----
发件人： Prof Brian Ripley <ripley at stats.ox.ac.uk>
收件人： Bingzhang Chen <elanchen2001 at yahoo.com.cn>
抄   送： r-help at r-project.org
发送日期： 2011/6/21 (周二) 5:56:05 下午
主   题： Re: [R] Italicize Greek symbols in axis

On Tue, 21 Jun 2011, Bingzhang Chen wrote:

> Hello there,
> 
> Is there any way to italicize Greek symbols such as mu in axis? From the help
> files of mathematical anotations: "Note that bold, italic and bolditalic do 
not
> apply to symbols, and hence not to the Greek symbols such as mu which are
> displayed in the symbol font.  They also do not apply to numeric constants.", 
>it
> seems that it cannot be done.

That refers to the mathematical symbol mu and not the Greek letter mu (it is not 
clear what you are actually quoting: maybe because in ?plotmath 'symbols' is 
emphasized).  And ?plotmath goes on to say

  This can often be used to display Greek \emph{letters} in bold or italic.

Did you try that?  So see if  "\u03bc" works, e.g.

plot(1:10)
text(5, 2, "\u03bc", font = 3)

On most devices there is no italic symbol font, and even if it were available, 
it is not included in the R graphics model of fonts 1:5. If you do have such a 
font family, you should be able to set it up as the 'family' argument of your 
(unspecified) graphics device.

Note that there is no italic version of the Adobe symbol font in the standard 
implementation of PDF nor postscript nor X11 nor in the Windows font set (and 
hence as far as I aware neither in the Apple version of those TrueType fonts).  
Some devices, e.g. those using cairographics, may synthesize an italic symbol 
font from glyphs in non-symbol fonts.

Please do remember to include the 'at a minimum' information requested in the 
posting guide: much better answers to questions like this can be given if you 
specify the platform and graphics device you use.


> Thanks,
> Bingzhang Chen

-- 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