← All chart types
map family
choropleth
Geographic regions colour-coded by value.
Country / state / county shapes, each filled with a colour scale to encode quantities (population, election results, GDP). Strong when location is intrinsic to the story.
When to use
Location is the natural axis of the comparison.
When NOT to use
Population sizes vary wildly (large empty regions dominate the eye even when their value is small) — consider symbol-map.
Rhetorical roles
- locate
- compare
Variants & related
Required primitives
- has_legend (colour scale)
Optional primitives
- has_title
- has_source_note
Common anti-patterns
- rainbow-palette
- choropleth-by-area-not-population
Disambiguation rules
- Geographic outline shapes filled with colour.
- If dots/circles overlay regions instead of filling, it is symbol-map.