ggplot2: Adding sample size information to x-axis tick labels

Question

This question is related to Create custom geom to compute summary statistics and display them *outside* the plotting region (NOTE: All functions have been simplified; no error

Answer 1

I have updated the EnvStats package to include a stat called stat_n_text which will add the sample size (the number of unique y-values) below each unique x-value. See the help file for stat_n_text for more information and a list of examples. Below is a simple example:

library(ggplot2)
library(EnvStats)

p <- ggplot(mtcars, 
  aes(x = factor(cyl), y = mpg, color = factor(cyl))) + 
  theme(legend.position = "none")

p + geom_point() + 
  stat_n_text() + 
  labs(x = "Number of Cylinders", y = "Miles per Gallon")