Sizing a ggplot precisely-CodePudding

I have got two ggplots, of which I want the size of the grey area to be exactly equal.

Now by playing around I can get very close by setting first plot width to 12 and second plot width to 14.

ggsave(filename="test1.png", myPlot, width = 12, height =12, dpi=300, units="cm", device='png')
ggsave(filename="test2.png", myPlot, width = 14, height =12, dpi=300, units="cm", device='png')

My question is whether I can pull some variable(s) from the first plot, so that I can automatically compute the right width for the second plot (ie, the width that makes the grey areas identical in size).

CodePudding user response：

Aside from the options already given by Allan, you might also find ggh4x::force_panelsizes() convenient to set sizes for plots (disclaimer: I wrote it).

library(ggplot2)

a <- ggplot(mpg, aes(displ, hwy, colour = cyl))  
  geom_point()

b <- ggplot(iris, aes(Sepal.Width, Sepal.Length, colour = Species))  
  geom_point()  
  guides(y.sec = "axis")

a   ggh4x::force_panelsizes(rows = unit(4, "cm"), cols = unit(5, "cm"))

b   ggh4x::force_panelsizes(rows = unit(4, "cm"), cols = unit(5, "cm"))

^{Created on 2022-11-04 by the}

^{Created on 2022-11-04 with reprex v2.0.2}