How to use subscripts in ggplot2 legends [R]

Question

Can I use subscripts in ggplot2 legends? I see this question on greek letters in legends and elsewhere, but I can\'t figure out how to adapt it.

I thought that using

Answer 1

The following should work (remove your line with names(temp) <-...):

ggplot(temp.m, aes(x = value, linetype = variable)) + 
  geom_density() + facet_wrap(~ a) +    
  scale_linetype_discrete(breaks=levels(temp.m$variable),
                          labels=c(expression(b[1]), expression(c[1])))

See help(scale_linetype_discrete) for available customization (e.g. legend title via name=).

Answer 2

If you want to incorporate Greek symbols etc. into the major tick labels, use an unevaluated expression.

For a bar graph, i did the following:

library(ggplot2)
data <- data.frame(names=tolower(LETTERS[1:4]),mean_p=runif(4))

p <- ggplot(data,aes(x=names,y=mean_p))
p <- p + geom_bar(colour="black",fill="white")
p <- p + xlab("expressions") + scale_y_continuous(expression(paste("Wacky Data")))
p <- p + scale_x_discrete(labels=c(a=expression(paste(Delta^2)),
                               b=expression(paste(q^n)),
                               c=expression(log(z)),
                               d=expression(paste(omega / (x + 13)^2))))
p