How to increase font size in a plot in R?

Question

I am confused. What is the right way to increase font size of text in the title, labels and other places of a plot? For example x <- rnorm(100) hist(x, xlim=range(x), xlab= "Variable Label", ylab="density", main="Title of plot", prob=TRUE, ps=30)The `ps` argument does not change font size (but it says in R Help for `?par` that it is for "the point size of text (but not symbols)".Also is it possible to separate changing the font size from the plotting function such as `hist`?

Answer 1

Given that you already ran the code line x <- rnorm(100), the following code allows you to increase the font size of the title, axis labels, and text on the axes in base R: 

hist(x, xlim=range(x), xlab= "Variable Label", ylab="density",

main="Title of plot", prob=TRUE, cex.main = 2, cex.lab = 2,cex.axis = 2)

The arguments cex.main, cex.lab, and cex.axis allow you to change the font size for the title, axis labels, and text on the axes respectively. Values greater than 1 increase the font size while values less than 1 decrease the font size.

It is also possible to separate changing the font size from the plotting function that generates the histogram. Given that you have already run the codes line x <- rnorm(100) and x.df <- data.frame(X=x), the following code allows you to increase the font size of the title, axis labels, and text on the axes by using the R library called ggplot2: 

library(ggplot2)

ggplot(x.df,aes(X,after_stat(density))) +

geom_histogram() +

xlim(range(x)) +

labs(x= "Variable Label", y= "density") +

ggtitle("Title of plot") +

theme( axis.text=element_text(size=30),

axis.title=element_text(size=30),

plot.title=element_text(size=30))

The code statement element_text(size=30) that is passed to the arguments axis.text, axis.title, and plot.title for the theme function allow you to change the font size for the title, axis labels, and text on the axes respectively. The values passed to the size argument for the element_text function specify the desired text size in points.