- in R, the easiest way to use mathematical notation and Greek letters
is using the 'expression' function. Here are a couple examples, with
the formatted output in the comments
`legend=c(expression(paste(plain(sin)*eta^2, posterior)),'2nd part of legend')`# posterior (\sin\eta\^2 posterior in Latex)- ...
`xlab=expression(kappa[lambda]),`.... # (\kappa_\lambda in Latex) `title(expression(nu == 1.3))`# (\nu=1.3 in Latex)

- another way, if you can't get expression to do it in R, or if you are working in S, is as follows.

Suppose I want my figure label to read '
'
. I can get partway there as follows:
`plot(x,y,xlab=NCEP,ylab=the
other axis) `
`mtext(side=1,line=3,font=13,s)
`
`mtext(side=1,line=3,0.995,cex=0.5)`

The font=13 specifies Greek letters. If you don't know which characters
correspond to which greek letters, you can play around some; s
is an obviously-inspired guess for . The problem here is
that this will pile NCEP, and 0.995 on top of each other.
So, next go into the postscript file, search for the characters of
interest, and move things around as necessary. (You might also be
able to do the moving around within R/S by using the `locator()`
function.) If it will be too hard to find something as common as 's',
you could replace it with something unusual in the R/S code and then
change it back in the postscript. Here's an example of the altered
postscript code with the original lines commented out with '`%`'.
`13 Sf `
`%(s) 61 2739 0.5 T `
`(s) 61 2784 0.5 T `
`1 Sf `
`0.8 Sx `
`%(0.995) 71 2739 0.5 T `
`(0.995) 81 2854 0.5 T `
`1 Sx`

The lines that are commented out with the '`%`' are what I
replaced in order to move the
and 0.995 to where I wanted them, based on trial and error. The two
numbers I changed in each line are the x and y coordinates of the
stuff in parentheses. Note that had I not included the '`font`'
and '`cex`' arguments in the S/R code, I could have just as
easily accomplished the same thing in the ps file by inserting the
'`13 Sf`' line to change the font to 13 and then the '`1
Sf`' line to change the font back, and similarly with the '`0.8
Sx`' and '`1 Sx`' lines.

Keywords: R, Greek, letters, figures, graphics

Last modified 6/23/07.