stackedbar() — Stacked bar chart

Bars split into parts that stack to a total.

barplot(rbind(a, b))

Key idea

• A stacked bar splits each bar into parts (segments) that add up to its total. (e.g. 20 + 30 + 50 = 100)
• It compares both overall totals and their inner composition (the mix of parts).
• Each coloured segment is one sub-group within the category. (e.g. Q1: Web 40, Store 60)
• Full bar height shows the grand total for that category. (e.g. total = 100)
• Useful for seeing how a mix changes across categories.

In plain words

Each bar is a stack of coloured blocks — the taller the stack, the bigger the total, and each block is one part of it.

Where you'd use it

• Each month you sold goods online and in-store, like January $8k online plus $5k in-store. A stackedbar makes each month’s bar $13k tall, with coloured sections showing how the $13k split between the two channels.
• Per game genre, stack satisfied players on top of unsatisfied ones; the full bar shows total players while the green section’s size reveals which genre keeps people happiest.
• A yearly budget bar split into rent, food, and savings lets you read both the total spend per year and how the mix shifts — for example savings growing from a thin sliver to a thick block over time.

Frequently asked questions

Why are stacked bars hard to read?

Only the bottom segment shares a baseline, so upper segments are hard to compare across bars.