Removing Unused Factors from a Facet in ggplot2

Question

I am trying to figure out a neat way to remove unused factors from a facet in ggplot2. Here is a minimal example

# DUMMY DATA
mydf = data.frame(
  x = rpois(         


        

Answer 1

I think all you need is scales = "free_y":

p0 = ggplot(mydf, aes(x = x, y = y)) +
  geom_point() +
  facet_wrap(~ cat, ncol = 1,scales = "free_y")

p0