Order discrete x scale by frequency/value

Question

I am making a dodged bar chart using ggplot with discrete x scale, the x axis are now arranged in alphabetical order, but I need to rearrange it so that it is ordered by the

Answer 1

The best way for me was using vector with categories in order I need as limits parameter to scale_x_discrete. I think it is pretty simple and straightforward solution.

ggplot(mtcars, aes(factor(cyl))) + 
  geom_bar() + 
  scale_x_discrete(limits=c(8,4,6))