violin() — Violin plot

Shows the shape of a distribution — fat where values are common.

vioplot(x)

Key idea

• A violin plot shows a box plot summary (middle and edges) plus the full shape of the data.
• The shape is a density curve — a smooth outline of how common each value is — mirrored on both sides for a symmetric look.
• Wider parts mean more values sit at that level; narrow parts mean fewer. (e.g. bulge near value 50)
• Two bulges reveal two clusters that a plain box plot would hide. (e.g. peaks at 20 and 80)
• It is useful for comparing the shape of several groups side by side. (e.g. group A vs group B)

In plain words

Imagine pouring all the values into a glass — the violin shows where they pile up the most and where they barely reach.

Where you'd use it

• Three classes sat the same test. Drawing a violin for each, you can see not just the medians but the full shape — class A bulges around 80 while class B is fat at both 50 and 90, hinting at two groups of students.
• Plot 200 clinic waiting times as a violin: if it shows two bulges, one near 10 minutes and one near 40, you have spotted two kinds of visits a boxplot would hide.
• A violin of 500 heights that is fat in the middle near 170 cm and thin at the ends confirms the values are evenly bunched around the average rather than split into clumps.

Frequently asked questions

Violin or boxplot?

A violin shows the full shape (and can reveal two peaks); a boxplot shows just the summary.