uniform panel width across multiple plots using grid.arrange

Question

When displaying several plots via facet_wrap(..., ncol = 1), the resulting plot widths are equal (even thou their axes texts differ in length).

Is it possible to achieve uniform widths (like in the left picture) using grid.arrange?

Fig.: facet_wrap on the left, grid.arrange on the right.

See [this SO answer](http://stackoverflow.com/a/13295880/496488) for a way to do that. — eipi10, Dec 02 '15 at 16:52
These certainly seem very closely related. I'm not 100% sure whether it counts as a duplicate. I'd like the OP to weigh in on whether the linked answer actually works in this case ... can you give a reproducible example? — Ben Bolker, Dec 02 '15 at 16:54
Seems fairly identical to me, but I will defer hammering it in deference to Ben's advice. (I just saw a question for which I had tested code, with an answer in two lines of code, closed as "too broad".) — IRTFM, Dec 02 '15 at 17:00
Interesting. Which of the `grob$widths` specifies the width of the main panel? Can I set it to some arbitrary value, rather than extract the value from other plots? If yes, how? — jakub, Dec 02 '15 at 17:16
don't know, and the results look a little inscrutable (try printing out `maxWidth` ...). Try experimenting? — Ben Bolker, Dec 02 '15 at 17:31

score 0 · Accepted Answer · edited May 23 '17 at 12:15

Confirming that the linked answer actually works for this case:

Make up some data:

d <- data.frame(lab=c(paste("very very very very long label ......",1:2),
                      paste("sL",1:2)),
                f=rep(c("A","B"),each=2))

d$z <- 1:4

library("ggplot2"); theme_set(theme_bw())
library("gridExtra")

Generate two plots:

g1 <- lapply(split(d,d$f),
             function(dd) 
                 ggplot(dd,aes(x=lab,y=z))+geom_bar(stat="identity")+
                     coord_flip()+labs(x=""))

Now apply the suggested answer:

gA <- ggplotGrob(g1[[1]])
gB <- ggplotGrob(g1[[2]])
maxWidth <- grid::unit.pmax(gA$widths[2:5], gB$widths[2:5])
gA$widths[2:5] <- as.list(maxWidth)
gB$widths[2:5] <- as.list(maxWidth)
grid.arrange(gA, gB, ncol=1)

uniform panel width across multiple plots using grid.arrange

1 Answers1