mapsapi package provides an interface to the Google Maps APIs, currently four of them:
mp_geocode are used to access the Directions, Matrix and Geocode APIs, respectively. They return an
xml_document object (package
xml2) with the response contents.
Given a directions response, functions
mp_get_segments can be used to process the response document into a spatial layer. Function
mp_get_routes gives each alternative as a separate line, while function
mp_get_segments gives each segment (that is, a portion of the route associated with specific driving instructions) as a separate line.
Given a distance matrix response, function
mp_get_matrix can be used to obtain distance/duration matrices.
Given a geocode response, functions
mp_get_bounds can be used to obtain geocoded locations as a point or polygon (bounds) layer.
The fourth function
mp_map is used to access the Maps Static API. It returns a
stars raster RGB image, which can be used as background in maps.
The CRAN version can be installed with:
The development version can be installed using
Once installed, the package can be loaded with
Note: due to new Google Maps API policy, starting from June 2018 the functions require an API key.
key = "AIz....."
The complete documentation can be found at https://michaeldorman.github.io/mapsapi/.
The following code section obtains (and plots) the driving directions from New-York to Los Angeles.
# Get routes (XML document) doc = mp_directions( origin = "New-York", destination = "Los Angeles", alternatives = TRUE, key = key, quiet = TRUE ) # Extract lines 'sf' layer r = mp_get_routes(doc) # Plot library(maps) library(sf) #> Linking to GEOS 3.8.0, GDAL 3.0.4, PROJ 6.3.1 map("state", fill = FALSE, col = "grey") plot(st_geometry(r), col = c("red", "green", "blue"), add = TRUE)