ggplot2 align top of two facetted plots

Question

I need to arrange two faceted graphs, like so:

d = data.frame(Index = LETTERS[1:5],x=1:5,y=1:5)
A = ggplot(subset(d,Index == 'A'),aes(x,y)) + 
  theme_bw() + 
  theme(axis.title.x = element_blank()) + 
  geom_point() + facet_wrap(~Index) + labs(title = "Title, The Title", 
                                           subtitle = "Subtitle, The Subtitle",
                                           y = "Side Axes")
B = ggplot(subset(d,Index != 'A'),aes(x,y)) +
  theme_bw() + 
  theme(axis.title.x = element_blank(), axis.title.y = element_blank()) + 
  geom_point() + facet_wrap(~Index) + labs(title = "", subtitle = "")
g = gridExtra::arrangeGrob(A,B,ncol=2,bottom="Bottom Axes")
grid.arrange(g)

Which produces the following:

As you can see from the above, there is a slight misalignment between the top edges of the plot region. This is caused by the 'commas' in the title and subtitles.

Does anyone know how I can enforce the top edges to align? I need a title and subtitle on the left plot, with an (empty) title, subtitle on the right one.

Answer 1

@CephBirk's solution is a clever and easy way to go here. For cases where a hack like that doesn't work, you can remove the title and sub-title from your plots and instead create separate grobs for them that you can lay out, along with the plots, using grid.arrange and arrangeGrob . In the code below, I've also added a nullGrob() as a spacer between plots A and B , so that the right x-label ( 1.50 ) in the left graph isn't cut off.

library(gridExtra)

A = ggplot(subset(d,Index == 'A'),aes(x,y)) + 
  theme_bw() + 
  theme(axis.title = element_blank()) + 
  geom_point() + facet_wrap(~Index) 

B = ggplot(subset(d,Index != 'A'),aes(x,y)) +
  theme_bw() + 
  theme(axis.title.x = element_blank(), axis.title.y = element_blank()) + 
  geom_point() + facet_wrap(~Index) 

grid.arrange(
  arrangeGrob(
    arrangeGrob(textGrob("Title, The Title", hjust=0), 
                textGrob("Subtitle, The Subtitle", hjust=0, gp=gpar(cex=0.8))),
    nullGrob(), ncol=2, widths=c(1,4)),
  arrangeGrob(A, nullGrob(), B, ncol=3, widths=c(8,0.1,8),
              left="Side Axes", bottom="Bottom Axes"), 
  heights=c(1,12))

Answer 2

It's a bit hackish, but you can have the same title and subtitle on the right as the left but print it in white font. :) You said it's due to the commas, so that fixes it.

Not the most satisfying, but it gets the job done.

B = ggplot(subset(d,Index != 'A'),aes(x,y)) +
theme_bw() + 
theme(axis.title.x = element_blank(), axis.title.y = element_blank(), title = element_text(color = 'white')) + 
geom_point() + facet_wrap(~Index) +
labs(title = "Title, The Title", subtitle = "Subtitle, The Subtitle")

Answer 3

egg::ggarrange(A, B, ncol=2, bottom="Bottom Axes")