Thursday, February 23, 2012

Violin Plots

Violin plots are an excellent way of displaying the distribution of a continuous variable by levels of a categorical variable. In essence, violin plots are box plots and kernel density plots combined. For instance, here are a set of violin plots from Stata's auto data:

These same data could also be displayed in tabular form, but again this is case in which a graphical display is a more effective way to examine and convey the patterns in the data.