--- title: "Get started wit arcgeocoder" output: rmarkdown::html_vignette desc: > Quick examples showing what arcgeocoder can do for you. vignette: > %\VignetteIndexEntry{Get started wit arcgeocoder} %\VignetteEngine{knitr::rmarkdown} %\VignetteEncoding{UTF-8} bibliography: REFERENCES.bib link-citations: true --- The goal of **arcgeocoder** is to provide a light interface for geocoding addresses and reverse geocoding location trough the [ArcGIS REST API Geocoding Service](https://developers.arcgis.com/rest/geocode/api-reference/overview-world-geocoding-service.htm). Full site with examples and vignettes on ## Why **arcgeocoder**? **arcgeocoder** is a package that provides a lightweight interface for geocoding and reverse geocoding with the ArcGIS REST API service. The goal of **arcgeocoder** is to access the ArcGIS REST API with fewer dependencies, such as **curl** . In some situations, **curl** may not be available or accessible, so **arcgeocoder** uses base functions to overcome this limitation. The interface of **apigeocoder** is built with the aim of easing the access to all the features provided by the API. The API endpoints used by **arcgeocoder** are `findAddressCandidates` and `reverseGeocode`, which can be accessed without the need for an API key. ## Recommended packages There are other packages much more complete and mature than `nominatimlite`, that presents similar features: - [**tidygeocoder**](https://jessecambon.github.io/tidygeocoder/) [@R-tidygeocoder]. Allows to interface with ArcGIS, Nominatim (OpenStreetMaps), Google, TomTom, Mapbox, etc. for geocoding and reverse geocoding. - [**nominatimlite**](https://dieghernan.github.io/nominatimlite/) [@R-nominatimlite]. Similar to **arcgeocoder** but using data from OpenStreetMaps trough the [Nominatim API](https://nominatim.org/release-docs/latest/) service. ## Usage ### Geocoding and reverse geocoding *Note: examples adapted from **tidygeocoder** package* In this first example we will geocode a few addresses using the `arc_geo()` function. Note that **arcgeocoder** works straight away, and you don't need to provide any API key to start geocoding! ``` r library(arcgeocoder) library(dplyr) # create a dataframe with addresses some_addresses <- tribble( ~name, ~addr, "White House", "1600 Pennsylvania Ave NW, Washington, DC", "Transamerica Pyramid", "600 Montgomery St, San Francisco, CA 94111", "Willis Tower", "233 S Wacker Dr, Chicago, IL 60606" ) # geocode the addresses lat_longs <- arc_geo(some_addresses$addr, lat = "latitude", long = "longitude") #> | | | 0% | |================= | 33% | |================================= | 67% | |==================================================| 100% ``` Only a few fields are returned from the geocoder service in this example, but `full_results = TRUE` can be used to return all of the data from the geocoder service. |query | latitude| longitude|address | score| x| y| xmin| ymin| xmax| ymax| wkid| latestWkid| |:------------------------------------------|--------:|----------:|:-----------------------------------------------------------------|-----:|----------:|--------:|----------:|--------:|----------:|--------:|----:|----------:| |1600 Pennsylvania Ave NW, Washington, DC | 38.89768| -77.03655|1600 Pennsylvania Ave NW, Washington, District of Columbia, 20500 | 100| -77.03655| 38.89768| -77.03755| 38.89668| -77.03555| 38.89868| 4326| 4326| |600 Montgomery St, San Francisco, CA 94111 | 37.79519| -122.40279|600 Montgomery St, San Francisco, California, 94111 | 100| -122.40279| 37.79519| -122.40379| 37.79419| -122.40179| 37.79619| 4326| 4326| |233 S Wacker Dr, Chicago, IL 60606 | 41.87889| -87.63602|233 S Wacker Dr, Chicago, Illinois, 60606 | 100| -87.63602| 41.87889| -87.63702| 41.87789| -87.63502| 41.87989| 4326| 4326| To perform reverse geocoding (obtaining addresses from geographic coordinates), we can use the `arc_reverse_geo()` function. The arguments are similar to the `arc_geo()` function, but now we specify the input data columns with the `x` and `y` arguments. The dataset used here is from the geocoder query above. The single line address is returned in a column named by the `address`. ``` r reverse <- arc_reverse_geo( x = lat_longs$longitude, y = lat_longs$latitude, address = "address_found" ) #> | | | 0% | |================= | 33% | |================================= | 67% | |==================================================| 100% ``` | x| y|address_found | |----------:|--------:|:----------------------------------------------------------------------------| | -77.03655| 38.89768|White House, 1600 Pennsylvania Ave NW, Washington, DC, 20500, USA | | -122.40279| 37.79519|Mbia Insurance Corporation, 600 Montgomery St, San Francisco, CA, 94111, USA | | -87.63602| 41.87889|Liberty Hands Cleaning, 233 S Wacker Dr, Ste 1011, Chicago, IL, 60606, USA | It is possible also to search for specific locations within or near a reference are or location using [category filtering](https://developers.arcgis.com/rest/geocode/api-reference/geocoding-category-filtering.htm). See more information in the documentation of the data base `arc_categories`. In the following example we would look for POIs related with food (i.e. Restaurants, Coffee Shops, Bakeries) near the Eiffel Tower in France. ``` r library(ggplot2) # For plotting # Step 1: Locate Eiffel Tower, using multifield query eiffel_tower <- arc_geo_multi( address = "Tour Eiffel", city = "Paris", countrycode = "FR", langcode = "FR", custom_query = list(outFields = "LongLabel") ) # Display results eiffel_tower %>% select(lon, lat, LongLabel) #> # A tibble: 1 × 3 #> lon lat LongLabel #> #> 1 2.29 48.9 Tour Eiffel, 3 Esplanade des Ouvriers de la Tour Eiffel, 75007, 7e Arrondissement, … # Use lon,lat to boots the search and using category = Food food_eiffel <- arc_geo_categories("Food", x = eiffel_tower$lon, y = eiffel_tower$lat, limit = 50, full_results = TRUE ) # Plot by Food Type ggplot(eiffel_tower, aes(x, y)) + geom_point(shape = 17, color = "red", size = 4) + geom_point(data = food_eiffel, aes(x, y, color = Type)) + labs( title = "Food near the Eiffel Tower", subtitle = "Using arcgecoder", color = "Type of place", x = "", y = "", caption = "Data from ArcGIS REST API services" ) ``` ![Example: Food places near the Eiffel Tower](./eiffel-1.png) ### **arcgeocoder** and **r-spatial** See additional articles showing how **arcgeocoder** can be use in combination with **leaflet** to create [dynamic maps](https://dieghernan.github.io/arcgeocoder/articles/ex_leaflet.html) and with **sf** and **terra** to create [static maps](https://dieghernan.github.io/arcgeocoder/articles/ex_static.html). ## References