Geocoding and Reverse Geocoding Services are widely used to provide data about coordinate and location information, including longitude, latitude, formatted location name, administrative region with different levels. There are some package can provide geocode service such as tidygeocoder, baidumap and baidugeo. However, some of them not always provide precise information in China, and some of them is unavailable with upgrade backend API.
amapGeocode is built to provide high precise geocoding and reverse geocoding service which powered by AutoNavi Map API service. Here are two main functions to use are
getCoord() which takes a character location name as an input and
getLocation() which takes two numeric longitude and latitude values as inputs.
getCoord() function extracts coordinate information from input character location name and output the result as
JSON (as list). And the
getLocation() function extracts location information from input numeric longitude and latitude values and output the result as
JSON (as list). With the
tibble format as output, it’s highly readable and easy to be used to
Before start geocoding and reverse geocoding, please apply a AutoNavi Map API Key. Set
amap_key globally by following command:
Then get result of geocoding, by
The response we get from AutoNavi Map API is JSON or XML. For readability, we transform them to
data.table, by setting
to_table argument as
TRUE by default.
If anyone want to get response as JSON or XML, just set
to_table = FALSE. If anyone want to extract information from JSON or XML. The result can further be parsed by
extractCoord is created to get result as a data.table.
get result of reverse geocoding, by
extractLocation is created to get result as a data.table.