Greek Letters in ggplot

If you need to include greek letters or special characters in a plot use annotate() instead of geom_text(). On my machine it preforms a lot faster.

# 57.62977 secs
geom_text(aes(x = 15, y = 25, label = "phi~22.5"), parse=TRUE)
# 1.988642 secs
annotate("text", x = 15, y = 25, parse = TRUE, label = as.character(expression(paste(phi, " 22.5"))))