7

When creating plots using ggplot2, I often encounter the following:

I have twitched all the text using element_text(size=<value>), so it looks good in my report, but to use it in another context, I need to update the size of all text (make it bigger or smaller), to keep the plot readable.

Is there a way to update font size for all text elements, without having to explicitly specifying the elements, i.e. not 

theme_update(
       axis.text=element_text(size=12),
       axis.title=element_text(size=14),
       ...
)

Reprex

library(ggplot2)
p <- ggplot(iris) +
  aes(Sepal.Width, Sepal.Length, color = Species)+
  geom_point()+
  ggtitle(
    "All text",
    "should be 50% larger"
  ) +
  theme_bw()
p

Created on 2019-09-25 by the reprex package (v0.3.0)

Benjamin Schwetz
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1 Answers1

11

ggplot objects are displayed through grid graphics, and grid graphics inherit the parent viewport's cex setting as a multiplier,

print(p, vp=grid::viewport(gp=grid::gpar(cex=2)))

or (to only affect the theme elements, but won't affect e.g. geom_text layers),

p + theme(text=element_text(size=24))
user12117520
  • 136
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  • Could you please elaborate on the code in your answer? I can see that `cex` get's the job done, but using `print` with a `vp` argument seems a bit arcane, at least to me. – Benjamin Schwetz Sep 25 '19 at 08:13
  • the second approach does also not work, if font sizes for the individual elements were previously specified by adding a theme to the plot. – Benjamin Schwetz Sep 25 '19 at 11:27