How to set a max limit to the characters of the values that are displayed on the y-axis of a plot, through the ggplot code?

Question

I have the stacked bar chart below and I would like to know if it is possible to set a max limit of characters displayed in the values of the y-axis, for example 4, and then add a "." at the point that the characters stop. For example "subcompact" should become "subc."

g <- ggplot(mpg, aes(class))

g+geom_bar(aes(fill = drv), position = position_stack(reverse = TRUE)) +
  coord_flip() +
  theme(legend.position = "top")

Answer 1

如果您不想更改源数据，也可以用ggplot代码进行替换-这是略有不同的regex解决方案@AndreElrico的

g <- ggplot(mpg, aes(sub(class,pattern = "(\\w{4}).*",replacement = "\\1.")))

Answer 2

change your variable into your desired variable before using it.

mpg$class <- sub("(?<=^.{4}).*",".", mpg$class, perl = T)

You can use regex to archive this.

Answer 3

You can adjust the labels with scale_x_discrete , which means no editing of the dataset is done.

g+geom_bar(aes(fill = drv), position = position_stack(reverse = TRUE)) +
  scale_x_discrete(
    labels = function(x) {
      is_long <- nchar(x) > 4
      x[is_long] <- paste0(substr(x[is_long], 1, 4), ".")
      x
    }
  ) +
  coord_flip() +
  theme(legend.position = "top")