113

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.

chl
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jeannot
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2 Answers2

129

Use theme_set()

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

enter image description here

Luciano Selzer
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    Very useful! In case anyone is interested, the default text size is **11** (`theme_gray()$text$size`) – Keith Hughitt Jul 11 '16 at 21:28
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    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 – micstr Feb 10 '17 at 14:40
61

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)
Andrew Brēza
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Thierry
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