How to change the default font size in ggplot2

Question

I'd like to know if it is possible to change some default parameters of ggplot2 graphics, like font size for instance, for a whole R session. The idea is to avoid setting them for each plot.

Solution 1

Use theme_set()

theme_set(theme_gray(base_size = 18))
qplot(1:10, 1:10)

Solution 2

Use theme_set if you want to update for the remainder of your active session:

theme_set(theme_grey(base_size = 18)) 

If you only want to change one graph you can set the base_size in the theme:

qplot(1:10, 1:10) + theme_grey(base_size = 18) 
ggplot(mtcars, aes(x = mpg, y = cyl)) + 
geom_point() +
theme_grey(base_size = 18) 

Comments

[Keith Hughitt]

Very useful! In case anyone is interested, the default text size is 11 (theme_gray()$text$size)

[micstr]

under new ggplot2 2.2.1 I do not see base_size under theme listed but it seems to work. I noticed my geom_text for showing text of a mean is not inheriting this base_size change. Anyone have luck with getting this to work