[R] Greek letters and formatted text

[Thomas Bschorr]

Hi,

I desperately try to do s.th. like

m=1.23455
sig=0.84321

plot(1,1)

text(0.8,1,sprintf("<Sigma>=%1.2f±%1.2f",m,sig))

where actually the greek letter should appear for Sigma.
I have tried all sorts of combinations with expression and paste etc. but could not work it out. Maybe someone has an idea and can help me.

Thanks a lot+

Thomas