Axis title alignment with mixed multiple graphs in R

I'm using ggplot2 package to make my graphs. I have 2 graphs, that I mixed using plot_grid() from cowplot package.

library(ggplot2)
library(cowplot)

x1 <- c(52.67, 46.80, 41.74, 40.45)
y1 <- c(1.726219351, 1.842421805, 1.790801758, 1.449997494)
x2 <- c(51.07, 65.97, 61.01, 49.25)
y2 <- c(5.39765063, 0.215293169, 0.694595893, 1.501089083)

DF <- data.frame(x1, y1, x2, y2)

p1 <- ggplot(DF, aes(x1, y1)) + 
  geom_point() +
  theme(aspect.ratio = 1)

p2 <- ggplot(DF, aes(x2, y2)) + 
  geom_point() +
  theme(aspect.ratio = 1)

plot_grid(p1, p2)

plot_grid(p1, p2, align = "hv")

The y axis of the second graph (p2) is larger than the y axis of the plot p1 (red line in the image), só I used align, from the cowplot package. However, the y axis label stays in the same position as the original plot (p2) size (blue line in the image). Is there a way to make the label to stand near to the y axis as the original plot?

Solution

Alignment of graphs with fixed axis ratio can be difficult. In any case, if you use the axis argument in addition to align things work. For more details, see here: https://wilkelab.org/cowplot/articles/aligning_plots.html

library(ggplot2)
library(cowplot)
#> 
#> ********************************************************
#> Note: As of version 1.0.0, cowplot does not change the
#>   default ggplot2 theme anymore. To recover the previous
#>   behavior, execute:
#>   theme_set(theme_cowplot())
#> ********************************************************

x1 <- c(52.67, 46.80, 41.74, 40.45)
y1 <- c(1.726219351, 1.842421805, 1.790801758, 1.449997494)
x2 <- c(51.07, 65.97, 61.01, 49.25)
y2 <- c(5.39765063, 0.215293169, 0.694595893, 1.501089083)

DF <- data.frame(x1, y1, x2, y2)

p1 <- ggplot(DF, aes(x1, y1)) + 
  geom_point() +
  theme(aspect.ratio = 1)

p2 <- ggplot(DF, aes(x2, y2)) + 
  geom_point() +
  theme(aspect.ratio = 1)

plot_grid(p1, p2, align = "hv", axis = "tbrl")

^{Created on 2019-07-26 by the reprex package (v0.3.0)}