4  Six geoms

4.1 geom_histogram()

4.2 geom_density()

library(ggplot2)
ggplot(faithful, aes(x = eruptions, y = after_stat(density))) +
  geom_histogram(breaks = seq(1.5, 5.5, .25), color = "blue",
                 fill = "cornflowerblue", alpha = .5) +
  geom_density(linewidth = 1.5, color = "red")