Sebastian Sauer builds a combo chart:
Overlaying a histogram (possibly facetted) is not something far fetched when analyzing data. Surprisingly, it appears (to the best of my knowledge) that there’s no comfortable out-of-the-box solution in ggplot2, although it can be of course achieved with some lines of code. Here’s my take.
Click through for Sebastian’s version, as well as information on the ggh4x library.