r - Too many factors on x axis

Question

What's the best way to deal with too many factors in a plot, assuming that the factor variable is ordered? The default doesn't look nice:

ggplot(data.frame(x=factor(trunc(runif(10000, 0, 100)), ordered=T)), aes(x=x)) +
  geom_histogram()

Answer 1

You can flip the values.

ggplot(data.frame(x=factor(trunc(runif(10000, 0, 100)), ordered=T)), aes(x=x)) +
  theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
  geom_histogram()

flip <- ggplot(data.frame(x=factor(trunc(runif(10000, 0, 100)), ordered=T)), aes(x=x)) +
  theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
  geom_histogram()

If it's still too dense for your taste, you can set manual breaks. In this case, I use five.

prune <- ggplot(data.frame(x=factor(trunc(runif(10000, 0, 100)), ordered=T)), aes(x=x)) +
  theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
  scale_x_discrete(breaks = seq(0, 100, by = 5)) +
  geom_histogram()

library(gridExtra)
grid.arrange(flip, prune)