通过拼凑对齐多个图例

In 这个小插曲 https://patchwork.data-imaginist.com/articles/guides/layout.html#controlling-guides of 拼凑而成 https://cran.r-project.org/web/packages/patchwork/index.html解释了如何组合多个 ggplot。我遇到的一个困难是收集图例并在它们的标题字符数量相差很大时正确对齐/调整它们。

下面是一个示例 - 我希望“mpg”图例也左对齐/对齐，而不是在“大小”图例下方居中。有什么建议么？请注意，添加theme(legend.justification = "left")并不能解决问题。

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 https://reprex.tidyverse.org (v0.3.0)}

同时，这是由 Ilia Kats 修复的 https://github.com/thomasp85/patchwork/pull/140.

Using & theme(legend.justification = "left")（当保持图例分离/与情节对齐时）或+ plot_layout(guides = 'collect')（合并情节中的传说）现在可以了。

Use remotes::install_github("thomasp85/patchwork")更新patchwork（如果在 2020 年之前）。

详细示例：

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的情况是固定的：

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

但默认情况下仍然没有对齐：

(p1 / p3)

通过合并参考线对齐（现已修复）：

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

按左对齐（现已修复）：

(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 https://reprex.tidyverse.org (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)