X labels gets cut out for faceted ggplot in R

July 25, 2022

I formatted facet_wrap so that its lables will be on the at the plot bottom instead of on top of the plot (see pic attached).
When the faceted label is too long, it get’s cut out of the facet borders.
How can I override this to allow longer strings to be in front of the facet graph?

In the attached plot the second facet label (which is ‘really_really_really_long_lable_here’) gets cut.

I can change figure dimensions and text size but the optimal solution for me is to arrange the facet strip text to be in front of the figure itself and therefore to allow long strings to appear in full length.

Dataframe to recreate this example:

df <- data.frame(a = c(seq(1:10)), b = seq(1:10), group = c(rep('group1',5), rep('really_really_really_long_lable_here',5)), 
                 sex = c(rep(c('M','F'),5)))


ggplot(df, aes(sex,b, group = sex)) +
              geom_boxplot() +
              facet_wrap(~group, strip.position = "bottom") +
              theme(strip.placement = "outside",
                    strip.background = element_blank(),
                    text = element_text(size = 16)) +
              xlab(NULL)

example figure

>Solution :

You have a few options. I’ll save your plot as p to demonstrate:

library(ggplot2)

df <- data.frame(
  a = seq(1:10), 
  b = seq(1:10), 
  group = c(rep('group1', 5), rep('really_really_really_long_lable_here', 5)), 
  sex = c(rep(c('M', 'F'), 5))
)


p <- ggplot(df, aes(sex, b, group = sex)) +
  geom_boxplot() +
  facet_wrap(~group, strip.position = "bottom") +
  theme(strip.placement = "outside",
        strip.background = element_blank(),
        text = element_text(size = 16)) +
  xlab(NULL)

1. Change your facet layout:

p +
  facet_wrap(~group, ncol = 1, strip.position = "bottom")

2. Change the font size:

p +
  theme(strip.text = element_text(size = 6))

3. Use text wrapping:

# Wrapping function that replaces underscores with spaces
wrap_text <- function(x, chars = 10) {
  x <- gsub("_", " ", x)
  stringr::str_wrap(x, chars)
}

# Alternative wrapping function that just drops a linebreak in every 10
# chars
wrap_text2 <- function(x, chars = 10) {
  regex <- sprintf("(.{%s})", chars)
  gsub(regex, "\\1\n", x)
}

p +
  facet_wrap(
    ~group, strip.position = "bottom",
    labeller = as_labeller(wrap_text)
  )