[R] Bold Face in Plot

[Prof Brian Ripley]

On Mon, 2 Mar 2009, Rau, Roland wrote:

> Dear all,
>
> I am trying to plot some text in bold face which works fine:
>
> plot(0:1,0:1,type="n")
> text(x=0.5, y=0.5, labels=expression(bold("the-actual-string")))
>
> Now when I try to do the following, the displayed text reads thestring:
>
> thestring <- "the-actual-string"
> plot(0:1,0:1,type="n")
> text(x=0.5, y=0.5, labels=expression(bold(thestring)))

See ?substitute (or its wrapper bquote)  E.g.

> lab <- substitute(bold(thestring), list(thestring=thestring))
> text(x=0.5, y=0.5, labels=lab)

But, why are you setting plain text as an expression?  The better way 
to do this is

thestring <- "the-actual-string"
plot(0:1,0:1,type="n")
text(x=0.5, y=0.5, labels=thestring, font=2)

See ?par (and ?text).  There are subtle differences (e.g. how the 
baslines are aligned), and using plotmath when you do not need it will 
get you encountering those differences.

> Can someone tell me what I am doing wrong? I assume it is rather simple
> but I am stuck somehow.
>
> Thanks in advance,
> Roland
>
> P.S. I tried it using ("ancient") R 2.7.0 on Windows32 and version 2.8.1
> on GNU/Linux (Ubuntu 8.10).

-- 
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