register_map: Register a new feature type

In cartographer: Turn Place Names into Map Data

Register a new feature type

Description

This adds a new feature type that can then be used by all the geoms in this package. If registering from another package, this should occur in the .onLoad() hook in the package.

Usage

register_map(
  feature_type,
  data,
  feature_column,
  aliases = NULL,
  outline = NULL,
  lazy = TRUE
)

Arguments

feature_type	Name of the type. If registering from within a package, the suggested format is "<package name>.<map name>" to avoid clashes between packages.
data	A simple feature data frame with the map data, or a function that returns a data frame. When lazy is TRUE, the value will not be evaluated until the data is first accessed.
feature_column	Name of the column of data that contains the feature names.
aliases	Optional named character vector or list that maps aliases to values that appear in the feature column. This allows abbreviations or alternative names to be supported.
outline	Optional sf geometry containing just the outline of the map, or a function returning such a geometry. When lazy is TRUE, the value will not be evaluated until the data is first accessed.
lazy	When TRUE, defer evaluation of data and outline until it is used.

Details

Registration supports delayed evaluation (lazy loading). This is particularly useful for larger datasets, so that they are not loaded into memory until they are accessed.

Value

No return value; this updates the global feature registry.

See Also

vignette("registering_maps")

Examples

# register a map of the states of Italy from rnaturalearth using the
# Italian names, and providing an outline of the country
register_map(
  "italy",
  data = rnaturalearth::ne_states(country = "italy", returnclass = "sf"),
  feature_column = "name_it",
  outline = rnaturalearth::ne_countries(country = "italy", returnclass = "sf", scale = "large")
)

cartographer documentation built on March 19, 2026, 5:07 p.m.