geocoding: Geocoding to Find Coordinates and Addresses

In certe-medical-epidemiology/certegis: A Certe R Package for Geographic Information Science

Geocoding to Find Coordinates and Addresses

Description

Geocoding is the process of retrieving geographic coordinates based on text, such as an address or the name of a place (Wikipedia page). On the other hand, reverse geocoding is the process of retrieving the name and address from geographic coordinates (Wikipedia page).

Usage

geocode(
  place,
  as_coordinates = FALSE,
  only_netherlands = TRUE,
  api_key = read_secret("gis.api_key"),
  api_requests_per_second = 1
)

reverse_geocode(
  sf_data,
  api_key = read_secret("gis.api_key"),
  api_requests_per_second = 1
)

Arguments

place	a (vector of) names or addresses of places
as_coordinates	a logical to indicate whether the result should be returned as coordinates (i.e., class sfc_POINT)
only_netherlands	a logical to indicate whether only Dutch places should be searched
api_key	free API key created at https://geocode.maps.co
api_requests_per_second	number of requests per second
sf_data	an 'sf' object or an 'sfc' object (i.e., a vector with geometric sfc_POINTs). Can also be a character vector, in which case geocode() will be called first.

Details

These functions use OpenStreetMap (OSM), by using the API of https://geocode.maps.co.

geocode() provides geocoding and returns an 'sf' data.frame at default. In case of multiple results, the distance from the main Certe building in Groningen is leading.

reverse_geocode() provides reversed geocoding and returns a data.frame with the columns "name", "address", "zipcode" and "city".

For both functions, the https://geocode.maps.co API will only be called on unique input values, to increase speed.

Source

Data © OpenStreetMap contributors, ODbL 1.0. https://osm.org/copyright

Examples

## Not run: 

# geocoding: retrieve 'sf' data.frame based on place names
coord <- geocode("Van Swietenlaan 2, Groningen")
coord

# reverse geocoding: get the name and address
reverse_geocode(coord)

# places can be any text, and the results are prioritised based on
# the distance from the main Certe building, so:
reverse_geocode(c("Certe", "IKEA"))

hospitals <- geocode(c("Martini ziekenhuis",
                       "Medisch Centrum Leeuwarden",
                       "Tjongerschans Heerenveen",
                       "Scheper Emmen"))
hospitals

if (require("certeplot2")) {
  geo_gemeenten |>
    crop_certe() |>
    plot2(datalabels = FALSE) |>
    add_sf(hospitals, colour = "certeroze", datalabels = place)
}


## End(Not run)

certe-medical-epidemiology/certegis documentation built on Dec. 10, 2024, 6:27 a.m.