[R] Underline in expression().

[Sundar Dorai-Raj]

John Janmaat wrote:
> Hello All,
> 
> Is there an analogue to \underbar or the AMS math \underline in 
> graphical math expressions?
> 
> Thanks,
> 
> John.

Uwe Ligges posted a solution a couple of years ago. I don't know if 
there is anything built in yet. ?plotmath does not seem to say anything 
about underlining.

http://finzi.psych.upenn.edu/R/Rhelp01/archive/7191.html

plot(0:1, 0:1, type="n")
underlined(0.5, 0.5, expression(widehat(x %*% y)))

--sundar