CODEWITHSUNDEEP
rggplot2
llewmills
llewmills

Reputation: 3568

Italicise greek letters in ggplot

This is getting very fussy now, but is there any way to italicise facet headings in ggplot2?

I have no problems getting the greek characters

i2 <- iris %>% transform(Species = factor(ifelse(Species == "setosa", "mu",
                                                 ifelse(Species == "versicolor", "sigma", "tau"))))


ggplot(i2, aes(Sepal.Width, Sepal.Length)) + 
       geom_point() + 
       facet_grid(.~Species, labeller = label_parsed)

enter image description here

However if I try to italicise 

i3 <- iris %>% transform(Species = factor(ifelse(Species == "setosa", "italic(mu)",
                                                 ifelse(Species == "versicolor", "bold(sigma)", "tau"))))

ggplot(i3, aes(Sepal.Width, Sepal.Length)) + 
       geom_point() + 
       facet_grid(.~Species, labeller = label_parsed)

Nothing happens and it looks the same as the original plot.

Upvotes: 2

Views: 542

Answers (1)

elcortegano
elcortegano

Reputation: 2684

Extending on @Ben Bolker comment, you can work this out using Unicode characters for the Greek letters you want to italize / make bold. This will also work in case where you might want to to this by means of italic() or bold() functions within expression() calls.

In your case it is enough to replace mu with \u03BC, and sigma with \u03C3:

i3 <- iris %>% transform(Species = factor(ifelse(Species == "setosa", "italic(\u03BC)",
                                                 ifelse(Species == "versicolor", "bold(\u03C3)", "tau"))))

ggplot(i3, aes(Sepal.Width, Sepal.Length)) + 
    geom_point() + 
    facet_grid(.~Species, labeller = label_parsed)

Upvotes: 1

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