Geocode addresses using the ‘HERE Geocoder’ and ‘HERE Geocoder Autocomplete’ APIs.
In order to geocode addresses, the function
geocode() is used. The requests are sent asynchronously, which means that every geocoded address is counting as one request. If the option
autocomplete is set to
TRUE, the addresses are sent to the ‘Geocoder Autocomplete’ API before geocoding, which improves matches but doubles the amount of requests. The addresses have to be of type
Geocode the character vector containing the addresses:
The return value is an
sf object containing
POINT geometries of the addresses:
head(geocoded, 3) #> Simple feature collection with 3 features and 8 fields #> geometry type: POINT #> dimension: XY #> bbox: xmin: 6.63222 ymin: 46.00297 xmax: 8.95121 ymax: 47.04954 #> epsg (SRID): 4326 #> proj4string: +proj=longlat +datum=WGS84 +no_defs #> id address postalCode city county state country type #> 1 1 Luzern, LU, Schweiz 6003 Luzern Luzern-Stadt LU CHE point #> 2 2 Lugano, TI, Svizzera 6900 Lugano Lugano TI CHE point #> 3 3 Lausanne, VD, Suisse 1003 Lausanne Lausanne VD CHE point #> geometry #> 1 POINT (8.30438 47.04954) #> 2 POINT (8.95121 46.00297) #> 3 POINT (6.63222 46.51961)
Not found addresses are deleted from the result. This means that the
sf object may contain fewer rows than the original number of addresses. The column
"id" matches the order of the the input addresses. Using the
"id" column a corresponding
"df" with the addresses to geocode could be joined to the coordinates after geocoding.
df <- data.frame( company = c("Schweizerische Bundesbahnen SBB", "Bahnhof AG", "Deutsche Bahn AG"), address = c("Wylerstrasse 123, 3000 Bern 65", "not_an_address", "Potsdamer Platz 2, 10785 Berlin"), stringsAsFactors = FALSE ) locs <- geocode(df$address) geocoded_sfdf <- st_as_sf(data.frame(locs, df[locs$id, ]))
Print the geocoded addresses on an interactive leaflet map:
The Geocoder Autocomplete API can be accessed using the
autocomplete() function. The
results parameter defines the maximum number of suggestions that should be requested for each address.
The return value is a
data.table containing autocomplete suggestions for the addresses. The variable
id matches the index of the initial address vector, which was used as input and
order stores the rank of the suggestion.
|Luzern||1||2||Schweiz, Luzern, Luzern-Stadt, Luzern|
|Luzern||1||3||Schweiz, Luzern, Luzern-Stadt|
|Lugano||2||2||Svizzera, Lugano, Lugano|
|Lugano||2||3||Svizzera, Lugano, Lugano, Lugano|
The reverse geocoding feature of the Geocoder API can be accessed using the
reverse_geocode() function. The function allows to retrieve addresses (
landmarks = FALSE) or landmarks (
landmarks = TRUE) near POIs.
The function returns an
sf object, containing the suggested addresses or landmark names of the reverse geocoded POIs. The coordinates are different from the initially provided POIs since they represent the locations of the suggested addresses or landmarks.
m <- mapview(poi, alpha.region = 0, col.region = "transparent", label = poi$city, cex = 30, layer.name = "POIs", map.types = c("Esri.WorldTopoMap"), homebutton = FALSE) + mapview(rev_addresses, col.region = "yellow", alpha = 0, label = rev_addresses$label, layer.name = "Adresses", homebutton = FALSE) + mapview(rev_landmarks, col.region = "red", alpha = 0, label = rev_landmarks$name, layer.name = "Landmarks", homebutton = FALSE) m
If no addresses or landmarks are found near a POI,
NULL for this POI is returned. In this case the rows corresponding to this particular POI are missing and merging the POIs by row is not possible. However, in the returned
sf object, the column
"id" matches the rows of the input POIs. The
"id" column can be used to join the original POIs.