Geocode addresses using the ‘HERE Geocoder’ and ‘HERE Geocoder Autocomplete’ APIs.

Geocode addresses

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. The addresses have to be of type character:

head(address, 3)
#> [1] "Luzern"   "Lugano"   "Lausanne"

Geocode the character vector containing the addresses:

geocoded <- geocode(address)

The return value is an sf object containing POINT geometries of the addresses:

head(geocoded, 3)
#> Simple feature collection with 3 features and 12 fields
#> geometry type:  POINT
#> dimension:      XY
#> bbox:           xmin: 6.63222 ymin: 46.00297 xmax: 8.9512 ymax: 47.04954
#> geographic CRS: WGS 84
#>   id                  address     type street house_number postal_code district
#> 1  1          Luzern, Schweiz locality   <NA>         <NA>        6003     <NA>
#> 2  2 Lugano, Ticino, Svizzera locality   <NA>         <NA>        6900     <NA>
#> 3  3   Lausanne, Vaud, Suisse locality   <NA>         <NA>        1003     <NA>
#>       city       county  state  country      access                 geometry
#> 1   Luzern Luzern-Stadt Luzern  Schweiz POINT EMPTY POINT (8.30437 47.04954)
#> 2   Lugano       Lugano Ticino Svizzera POINT EMPTY  POINT (8.9512 46.00297)
#> 3 Lausanne     Lausanne   Vaud   Suisse POINT EMPTY  POINT (6.63222 46.5196)

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 data.frame "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:

mapview(geocoded,
        label = geocoded$address,
        col.regions = "red",
        map.types = c("Esri.WorldTopoMap"),
        legend = FALSE,
        homebutton = FALSE
)

Autosuggestions

The Geocoder Autosuggest API can be accessed using the autosuggest() function. The results parameter defines the maximum number of suggestions that should be requested for each input address.

suggestions <- autocomplete(address, results = 3)

The return value is a data.frame 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.

results <- data.frame(
  input = address[suggestions$id],
  id = suggestions$id,
  rank = suggestions$rank,
  suggestion = suggestions$suggestion
)
input id rank suggestion
Luzern 1 1 Luzern, Schweiz
Luzern 1 2 Luzern-Stadt, Luzern, Schweiz
Luzern 1 3 Luzern-Land, Luzern, Schweiz
Lugano 2 1 Lugano, Ticino, Svizzera
Lugano 2 2 Villa Lugano, Ciudad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
Lugano 2 3 Stazione Lugano FFS

Reverse geocode POIs

The reverse geocoding feature of the Geocoder API can be accessed using the reverse_geocode() function. The function allows to retrieve addresses near POIs.

reverse_geocoded <- reverse_geocode(poi = poi, results = 3)

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$city, cex = 30, layer.name = "POIs",
          map.types = c("Esri.WorldTopoMap"), homebutton = FALSE) +
  mapview(reverse_geocoded, col.region = "red", alpha = 0,
          label = reverse_geocoded$label, layer.name = "Adresses",
          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.