This post describes all the available options to customize the chart
title with R
and ggplot2
. It shows how to
control its color, its position, and more.
ggplot2
title
It is possible to add a title to a ggplot2 chart using the
ggtitle()
function. It works as follow:
# library & data
library(ggplot2)
data <- data.frame(x=rnorm(100))
# Basic plot with title
ggplot( data=data, aes(x=x)) +
geom_histogram(fill="skyblue", alpha=0.5) +
ggtitle("A blue Histogram") +
theme_minimal()
It is a common need to set the title on several lines. To add a
break and skip to a second line, just add a \n
in the
text.
# title on several lines
ggplot( data=data, aes(x=x)) +
geom_histogram(fill="skyblue", alpha=0.5) +
ggtitle("A blue \nHistogram") +
theme_minimal()
Here are 2 tricks to control text appearance and its position. Both
features are controled thanks to the plot.title
argument of
the theme()
function. Appearance can be controlled with
option such as family
, size
or
color
, when position is controlled with
hjust
and vjust
.
# Custom title appearance
ggplot( data=data, aes(x=x)) +
geom_histogram(fill="skyblue", alpha=0.5) +
ggtitle("A blue Histogram") +
theme_minimal() +
theme(
plot.title=element_text(family='', face='bold', colour='purple', size=26)
)
# Adjust the position of title
ggplot( data=data, aes(x=x)) +
geom_histogram(fill="skyblue", alpha=0.8) +
ggtitle("With title on the right") +
theme_minimal() +
theme(
plot.title=element_text( hjust=1, vjust=0.5, face='bold')
)
If you want to highlight a specific set of words in the title, it is
doable thanks to the expression()
function.