[R] Including greek letters in a pairs() plot

[enrico.foscolo2 at libero.it]

Good Morning,

I have a stupid problem about inclusion of greek letters in a 
plot built with function pairs().

First of all, I have a matrix with 3 columns 
and 1000 rows and I would like to use pairs() in order to plot points in the 
upper panel and to compute correlation in the lower panel.

In the lower panel 
I would like to see the following text in each ij-plot: hat(rho)[i,j]=cor(x,y). 
Obviously, rho should be written in according to greek alphabet.

This is my 
function:

panel.cor <- function(x,y){

	cor<-0
	cor<-round(cor(x,y),4)
	text
(0.5,0.5,cor,cex=2)

}

Thank You very much,

Enrico Foscolo