Can you center a plot using R patchwork

Question

This is about organizing plots in R markdown document. Say we create three plots:

library(patchwork)
library(tidyverse)

a <- ggplot(mtcars, aes(mpg, wt)) + geom_point() + ggtitle("Plot A")
b <- ggplot(mtcars, aes(drat, wt)) + geom_point() + ggtitle("Plot B")
c <- ggplot(mtcars, aes(cyl, wt)) + geom_point() + ggtitle("Plot C")

My organization is:

Plot<- a+b+c +plot_layout(ncol = 2)

It’s OK. But what I really want is:

plot<- a /(b + c) + 
  plot_layout(ncol = 2)

Except that all three plots are the same size, the upper centered.

Something very similar can be done with plot_spacer():

plot<- plot_spacer() + a + plot_spacer() /(b + plot_spacer() + c) 

But that decrease the size of the plots. Is there a way to keep the size of the plots, only center the upper one?

Answer 1

design <- "
  #11#
  2233"

wrap_elements(full =  a) + b + c + plot_layout(design = design, widths = 1)

The wrap_elements part is used to make the plots equal in width. (Though I haven't been able to get them to be the same height without manually adding heights = c(1.2,1))

As the patchwork author notes here, "the issue is that the y-axis of the top plot influences the width of plots spanning it's location. The easiest way is to remove alignment from the top plot by putting it inside wrap_elements()."