[R] lower triangle of the correlation matrix with xtable

[Olga Lyashevska]

Dear all,

mydata<-data.frame(x1=c(1,4,6),x2=c(3,1,2),x3=c(2,1,3))
cor(mydata)
           x1         x2        x3
x1  1.0000000 -0.5960396 0.3973597
x2 -0.5960396  1.0000000 0.5000000
x3  0.3973597  0.5000000 1.0000000

I wonder if it is possible to fill only lower triangle of this
correlation matrix? Using 'dist' doesn't seem to be useful as it doesnt
allow to convert this table with xtable. 

print(xtable(cor(mydata),digits=3))

Any ideas?
Cheers,
Olga