Geographic centroid of locations

Assigns each point a longitude and latitude corresponding to the geographic centre of its administrative area. This means that all points in the same area will overlap. The default position uses position_circle_repel() to repel the points outwards with an amount controllable with its scale parameter.

Usage

geom_centroids(
  mapping = ggplot2::aes(),
  data = NULL,
  stat = "automap_coords",
  position = "circle_repel_sf",
  ...,
  fun.geometry = NULL,
  feature_type = NA,
  inset = NA,
  map_base = "clip",
  map_inset = "auto",
  na.rm = TRUE,
  show.legend = "point",
  inherit.aes = TRUE
)

Arguments

mapping, data, stat, position, na.rm, show.legend, inherit.aes, ...

See ggplot2::stat_sf_coordinates().

fun.geometry

A function that takes a sfc object and returns a sfc_POINT with the same length as the input. If NULL, function(x) sf::st_point_on_surface(sf::st_zm(x)) will be used. Note that the function may warn about the incorrectness of the result if the data is not projected, but you can ignore this except when you really care about the exact locations.

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.

Aesthetics

The location aesthetic is required. geom_centroids() understands the same aesthetics as ggplot2::geom_point().

Examples

library(ggplot2)

cartographer::nc_type_example_2 |>
  head(n = 100) |>
  ggplot(aes(location = county)) +
  geom_boundaries(feature_type = "sf.nc") +
  geom_centroids(aes(colour = type), position = position_circle_repel_sf(scale = 6), size = 0.5) +
  coord_automap(feature_type = "sf.nc")