The goal of this tutorial is to center the title of a plot in ggplot.
# First we load the libraries
library(ggplot2)
# In this example we will use the open repository of plants classification Iris.
data("iris")
str(iris)
## 'data.frame': 150 obs. of 5 variables:
## $ Sepal.Length: num 5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
## $ Sepal.Width : num 3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
## $ Petal.Length: num 1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 ...
## $ Petal.Width : num 0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 ...
## $ Species : Factor w/ 3 levels "setosa","versicolor",..: 1 1 1 1 1 1 1 1 1 1 ...
# Let's plot the petal length vs petal width
ggplot() + geom_point(data = iris, aes(x = Petal.Width, y = Petal.Length,color = Species))
# Let's add a pretty decent title to the plot
# However the title is justified to the left :/
ggplot() + geom_point(data = iris, aes(x = Petal.Width, y = Petal.Length,color = Species)) +
ggtitle("My dope plot")
# We can solve this by adjusting the title to be centered
# The instruction is a simple as intuitive
# Problem solved
ggplot() + geom_point(data = iris, aes(x = Petal.Width, y = Petal.Length,color = Species)) +
ggtitle("My dope plot")+
theme(plot.title = element_text(hjust = 0.5))
In this tutorial we have learnt how to center the title of a plot in ggplot.