Associate regions with counts — geom

Counts the number of occurrences of each location, then by default maps the count to the fill aesthetic. If your data has only one row per location and some other field that you'd like to map to aesthetics, use geom_sf() or geom_sf_inset() with stat = "automap" instead.

Usage

geom_choropleth(
  mapping = ggplot2::aes(),
  data = NULL,
  stat = "choropleth",
  position = "identity",
  ...,
  feature_type = NA,
  inset = NA,
  map_base = "normal",
  map_inset = "auto",
  na.rm = TRUE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_choropleth(
  mapping = NULL,
  data = NULL,
  geom = "sf",
  position = "identity",
  ...,
  feature_type = NA,
  na.rm = TRUE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping, data, stat, geom, position, na.rm, show.legend, inherit.aes, ...: See ggplot2::geom_sf().
feature_type: Type of map feature. See feature_types() for a list of registered types. If NA, the type is guessed based on the values in feature_names.
inset: Inset configuration; see configure_inset(). If NA (the default), this is inherited from the coord (see coord_sf_inset()).
map_base: Controls the layer with the base map. Possible values are "normal" to create a layer as though the inset were not specified, "clip" to create a layer with the inset viewport cut out, and "none" to prevent the insertion of a layer for the base map.
map_inset: Controls the layer with the inset map. Possible values are "auto" to choose the behaviour based on whether inset is specified, "normal" to create a layer with the viewport cut out and transformed, and "none" to prevent the insertion of a layer for the viewport map.

Value

A ggplot layer.

Details

Note that choropleths have a tendency to be misleading by emphasising geographically larger areas.

Aesthetics

The location aesthetic is required. geom_choropleth() understands the same aesthetics as ggplot2::geom_sf().

Computed variables

count: rows matching the region
geometry: sf geometry column
...: limits as computed by ggplot2::stat_sf()

Examples

library(ggplot2)

cartographer::nc_type_example_2 |>
  ggplot(aes(location = county)) +
  geom_choropleth() +
  geom_boundaries(feature_type = "sf.nc") +
  scale_fill_steps(low = "#e6f9ff", high = "#00394d") +
  coord_automap(feature_type = "sf.nc")