[R] Subscript and superscript on one symbol; plotmath.

[Rolf Turner]

I would like to produce, as graphical annotation, the Greek letter sigma
with a superscript of 2 and a subcript of 11.  (I.e. the top left hand
entry of a covariance matrix.)

I've tried:

plot(1:10,main=expression({sigma^2}[11]))

(and variants).  This "sort of" works but there is an undesirable
gap between the sigma and the subscript 11. (IOW the subscript is to
the right of the superscript, whereas ideally the first "1" in "11"
should be vertically below the superscript.

I've also tried (hammer and hope!):

plot(1:10,main=expression(sigma*atop(scriptstyle(2),scriptstyle(11))))

and again this "sort of" works but places the putative superscript a
bit too high and the putative subscript a bit too low.

Is there any way to achieve, with plotmath, an effect like unto that
produced by the LaTeX expression $\sigma^2_{11}$?  Or should I just
give up and go to the pub? :-)

cheers,

Rolf Turner

P.S.  I've explicitly CC-ed Paul Murrell, who is obviously the go-to
guy on such matters, in case he does not regularly monitor this list.

R. T.

-- 
Honorary Research Fellow
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276