Stacked histograms like in flow cytometry

Question

I\'m trying to use ggplot or base R to produce something like the following:

Answer 1

Using the ggridges package:

ggplot(my.data, aes(x = V1, y = factor(V2), fill = factor(V2), color = factor(V2))) +
  geom_density_ridges(alpha = 0.5)