[R] Greek characters in plots

[michael watson (IAH-C)]

Hi Brian

Thanks again for the advice, it is appreciated.

I had come across U0394 code through the character map, but I get:

> "\u0394"
Error: invalid \uxxxx sequence

So when I execute your code, I get:
> a <- "A)"
> b <- "stbA::cat"
> paste(a, "\u0394", b)
Error: invalid \uxxxx sequence

This is on both Rgui at home and at work (Windows Vista and R 2.6 at home, Windows XP and R 2.7 at work)

Thanks again, Gabor's suggestion worked.


-----Original Message-----
From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk]
Sent: Tue 05/08/2008 7:44 PM
To: michael watson (IAH-C)
Cc: Henrique Dallazuanna; r-help at r-project.org
Subject: RE: [R] Greek characters in plots
 
On Tue, 5 Aug 2008, michael watson (IAH-C) wrote:

> OK, I am definitely struggling here.
>
> The text I am trying to plot isn't a mathematical expression, it's:
>
> A) ?stbA::cat

OK, so you want a Greek character and not a Greek symbol.  As I said they 
are different (different fonts, different shapes aka glyphs).

> This is biological notation for a particular mutation.  The "A)" part is 
> a tag identifying the graph, and the "stbA::cat" bit is the gene that is 
> mutated.  Both the tag and gene are set as variables in a loop, and only 
> the delta remains the same.
>
> As the text I am trying to plot isn't a mathematical expression, I seem 
> to be having trouble getting substitute() and expression() to do what I 
> want.  As plotmath states "A mathematical expression must obey the 
> normal rules of syntax for any R expression", I fear I may be barking up 
> the wrong tree!
>
> Thank you all for your help so far, but can someone please help me once 
> more and tell me how I can get the capital Delta symbol so I can use it 
> in non-mathematical text and strings for plotting?

a <- "A)"
b <- "stbA::cat"
paste(a, "\u0394", b)

(Number from http://www.alanwood.net/unicode/greek.html .)  This should 
work in a UTF-8 locale and also on Windows (in a windows() device or in 
the Rgui console).

>
> Thanks once again
>
> Mick
>
> -----Original Message-----
> From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk]
> Sent: 05 August 2008 12:40
> To: michael watson (IAH-C)
> Cc: Henrique Dallazuanna; r-help at r-project.org
> Subject: Re: [R] Greek characters in plots
>
> On Tue, 5 Aug 2008, michael watson (IAH-C) wrote:
>
>> Excellent!  I even tried DELTA but not Delta....
>
> ?plotmath says
>
>       'Alpha' - 'Omega'               uppercase Greek symbols
>
> How could that be made clearer?
>
> (Note it carefully says Greek *symbols* not *character*: they are not the
> same thing.)
>
>> Now, how do I go about pasting that with some text that I have in various other variables?
>
> Use substitute?  E.g.
>
> substitute(expression(foo*Delta), list(foo=3))
>
> (Some people prefer bquote, but that is just a wrapper for substitute in
> R.)
>
>>
>> -----Original Message-----
>> From: Henrique Dallazuanna [mailto:wwwhsd at gmail.com]
>> Sent: 05 August 2008 12:17
>> To: michael watson (IAH-C)
>> Cc: r-help at r-project.org
>> Subject: Re: [R] Greek characters in plots
>>
>> Try,
>>
>> expression(Delta)
>>
>> On Tue, Aug 5, 2008 at 8:14 AM, michael watson (IAH-C)
>> <michael.watson at bbsrc.ac.uk> wrote:
>>> Hi
>>>
>>> I am running an R script that creates 100s of graphs, and I need to use
>>> the greek CAPITAL letter delta in the mtext() function.
>>>
>>> I got as far as expression(delta) but this gives me the lowercase
>>> version.
>>>
>>> Can anyone help?  I'm using R 2.7 on Windows XP
>>>
>>> Mick
>>>
>>> Head of Informatics
>>> Institute for Animal Health
>>> Compton
>>> Berks
>>> RG20 7NN
>>> 01635 578411
>>>
>>> http://www.iah.ac.uk/research/bioinformatics/bioinf.shtml
>>>
>>> The information contained in this message may be confide...{{dropped:14}}
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>>
>>
>> --
>> Henrique Dallazuanna
>> Curitiba-Paraná-Brasil
>> 25° 25' 40" S 49° 16' 22" O
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
> -- 
> 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
>

-- 
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