CODEWITHSUNDEEP
rggplot2axis
eze
eze

Reputation: 791

How to italicize part (one or two words) of an axis title

Is there any way to change the style of part of an axis title while keep the rest part unchanged? In my case, How could I italicize
"bacteria X" in the y-axis title? To my knowledge, the command theme(axis.title.y=element_text(face="italic")) can only change the whole y-aixs title, is it?

ggplot(fig1,aes(x=cf,y=Freq,fill=Var1)) +
geom_bar(stat="identity") +
labs(x="Groups",y="No. of bacteria X isolates with corresponding types",fill="Var1") +
theme(axis.title.y=element_text(face="italic"))

Upvotes: 79

Views: 122099

Answers (3)

Thomas Neitmann
Thomas Neitmann

Reputation: 2722

This can be achieved using element_markdown() from the ggtext package.

ggplot(fig1, aes(cf, Freq, fill = Var1)) +
  geom_bar(stat = "identity") +
  labs(
    x = "Groups",
    y = "No. of *bacteria X* isolates with corresponding types",
    fill = "Var1"
  ) +
  theme(axis.title.y = ggtext::element_markdown())

Notice the * around bacteria X in the y axis title. Setting axis.title.y to element_markdown has the effect that the axis title is rendered as markdown. Thus, text inside * will be displayed in italics.

An even easier solution is using the mdthemes package which provides themes that interpret text as makrdown out of the box, i.e. no need to call theme. Here's an example.

ggplot(mtcars, aes(hp, mpg)) +
  geom_point() +
  mdthemes::md_theme_classic() +
  labs(title = "**Bold Title**", x = "*Italics axis label*")

enter image description here

Upvotes: 35

TCS
TCS

Reputation: 471

I believe RFelber's suggestion is what you are after. Try this:

labs(x="Groups",
     y=expression('No. of'~italic(bacteria X)~'isolates with corresponding types'),
     fill="Var1")

I did not need to use the bquote() function. The tildes produce single spaces for terms that are outside of the quotes.

Upvotes: 20

Heroka
Heroka

Reputation: 13149

You could make an expression like this:

my_y_title <- expression(paste("No. of ", italic("bacteria X"), " isolates with corresponding types"))
.... + labs(y=my_y_title)

Upvotes: 78

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