get_googlemap: Get a Google Map.

Description

get_googlemap() queries the Google Maps Static API version 2 to download a static map. Note that in most cases by using this function you are agreeing to the Google Maps API Terms of Service at https://cloud.google.com/maps-platform/terms/. Note that as of mid-2018, registering with Google Cloud to obtain an API key is required to use any of Google's services, including get_googlemap(). Usage and billing may apply, see the links under See Also further down in this documentation for more details.

Usage

get_googlemap(
  center = c(lon = -95.3632715, lat = 29.7632836),
  zoom = 10,
  size = c(640, 640),
  scale = 2,
  format = c("png8", "gif", "jpg", "jpg-baseline", "png32"),
  maptype = GOOGLE_VALID_MAP_TYPES,
  language = "en-EN",
  messaging = FALSE,
  urlonly = FALSE,
  filename = NULL,
  color = c("color", "bw"),
  force = FALSE,
  where = tempdir(),
  archiving = FALSE,
  ext = "com",
  inject = "",
  region,
  markers,
  path,
  visible,
  style,
  ...
)

Value

a ggmap object (a classed raster object with a bounding box attribute)

Arguments

center: the center of the map; either a longitude/latitude numeric vector or a string containing a location, in which case geocode() is called with source = "google". (default: c(lon = -95.3632715, lat = 29.7632836), a reference to Houston, Texas)
zoom: map zoom; an integer from 3 (continent) to 21 (building), default value 10 (city)
size: rectangular dimensions of map in pixels - horizontal x vertical - with a max of c(640, 640). this parameter is affected in a multiplicative way by scale.
scale: multiplicative factor for the number of pixels returned possible values are 1, 2, or 4 (e.g. size = c(640,640) and scale = 2 returns an image with 1280x1280 pixels). 4 is reserved for google business users only. scale also affects the size of labels as well.
format: character string providing image format - png, jpeg, and gif formats available in various flavors
maptype: character string providing google map theme. options available are "terrain", "satellite", "roadmap", and "hybrid"
language: character string providing language of map labels (for themes with them) in the format "en-EN". not all languages are supported; for those which aren't the default language is used
messaging: turn messaging on/off
urlonly: return url only
filename: destination file for download (file extension added according to format). Default NULL means a random tempfile().
color: color or black-and-white
force: if the map is on file, should a new map be looked up?
where: where should the file drawer be located (without terminating "/")
archiving: use archived maps. note: by changing to TRUE you agree to the one of the approved uses listed in the Google Maps API Terms of Service : https://cloud.google.com/maps-platform/terms/.
ext: domain extension (e.g. "com", "co.nz")
inject: character string to add to the url
region: borders to display as a region code specified as a two-character ccTLD ("top-level domain") value, see https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains#Country_code_top-level_domains
markers: data.frame with first column longitude, second column latitude, for which google markers should be embedded in the map image, or character string to be passed directly to api
path: data.frame (or list of data.frames) with first column longitude, second column latitude, for which a single path should be embedded in the map image, or character string to be passed directly to api
visible: a location as a longitude/latitude numeric vector (or data frame with first column longitude, second latitude) or vector of character string addresses which should be visible in map extent
style: character string to be supplied directly to the api for the style argument or a named vector (see examples). this is a powerful complex specification, see https://developers.google.com/maps/documentation/maps-static/
...: ...

Author

David Kahle david@kahle.io