plot - Underline Text in a barplot in R

Question

I am trying to underline the mean value in the following plot:

dummy <- c(4, 9, 6, 5, 3)
barplot(dummy)
text(4, 8,paste('Average value', mean(dummy)))

I tried using underline() but it says it could not find the function.

text(4, 8,paste('Average value', underline(mean(dummy))))

Error:

could not find function "underline"

I am using : R version 3.1.0

Answer 1

Like this:

text(4, 8, bquote("Average value"~underline(.(mean(dummy)))))

or if you want the whole text underlined:

text(4, 8, bquote(underline("Average value"~.(mean(dummy)))))

Note use of bquote and .(x) to insert the value of a variable in the expression.