Align multiple legends with patchwork

Question

In this vignette of patchwork is explained how to combine multiple ggplots. One difficulty I encountered is to collect the legends and align/justify them properly when their titles are very different in number of characters.

Below is an example - I would like the 'mpg' legend to be also left justified / aligned and not centered beneath the 'Size' legend. Any suggestions? Note that, adding theme(legend.justification = "left") doesn't solve the problem.

library(ggplot2)
library(patchwork)

p1 <- ggplot(mtcars) + 
  geom_point(aes(mpg, disp, colour = mpg, size = wt)) + 
  guides(size = guide_legend(title = "Size - long title for the purpose of this example")) +
  ggtitle('Plot 1')

p2 <- ggplot(mtcars) + 
  geom_boxplot(aes(gear, disp, group = gear)) + 
  ggtitle('Plot 2')

p3 <- ggplot(mtcars) + 
  geom_point(aes(hp, wt, colour = mpg)) + 
  ggtitle('Plot 3')

(p1 | (p2 / p3)) + plot_layout(guides = 'collect')

^{Created on 2019-12-16 by the reprex package (v0.3.0)}

Answer 1

In the meantime, this was fixed by Ilia Kats.

Using & theme(legend.justification = "left") (when keeping legends separate/aligned with plot) or + plot_layout(guides = 'collect') (merging legends from plots) now just works.

Use remotes::install_github("thomasp85/patchwork") to update patchwork (if pre ~2020).

---

Detailed example:

library(ggplot2)
library(patchwork)

p1 <- ggplot(mtcars) +
  geom_point(aes(mpg, disp, colour = mpg, size = wt)) +
  guides(size = guide_legend(title = "Size - long title for the purpose of this example")) +
  ggtitle('Plot 1')

p2 <- ggplot(mtcars) +
  geom_boxplot(aes(gear, disp, group = gear)) +
  ggtitle('Plot 2')

p3 <- ggplot(mtcars) +
  geom_point(aes(hp, wt, colour = mpg)) +
  ggtitle('Plot 3')

OP's case is fixed:

(p1 | (p2 / p3)) + plot_layout(guides = 'collect')

But the default case is still not aligned:

(p1 / p3)

Align by merging guides (now fixed):

(p1 / p3) + plot_layout(guides = 'collect')

Align by left justification (now fixed):

(p1 / p3) & theme(legend.justification = "left")

(This would be desirable if there are no shared legends between the two plots ( so this just an bad example for the use))

^{Created on 2020-09-10 by the reprex package (v0.3.0)}

# Session info: 
R version 4.0.1 (2020-06-06),            
 ggplot2     * 3.3.1      2020-05-28 [1] CRAN (R 4.0.0)                        
 patchwork   * 1.0.1.9000 2020-09-10 [1] Github (thomasp85/patchwork@82a5e03)