Set number of bins for histogram directly in ggplot

Question

I\'d like to feed geom_histogram the number of bins for my histogram instead of controlling bins through binwidth. The documentation says I can do this

Answer 1

Just pass bins=x directly

library(ggplot2)
df <- data.frame(a = rnorm(10000))

ggplot(df, aes(x=a)) + geom_histogram()

Produces this (with warning "stat_bin() using bins = 30. Pick better value with binwidth."):

And this:

ggplot(df, aes(x=a)) + geom_histogram(bins=10)

Produces:

Using ggplot2 version 2.0.0