Get a Google Map.
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.
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, ... )
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 flavorsmaptype: 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 usedmessaging: turn messaging on/offurlonly: return url onlyfilename: destination file for download (file extension added according to format). Default NULL means a random tempfile().color: color or black-and-whiteforce: 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 urlregion: 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_domainsmarkers: 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 apipath: 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 apivisible: 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 extentstyle: 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/...: ...a ggmap object (a classed raster object with a bounding box attribute)
## Not run: requires Google API key, see ?register_google ## basic usage ######################################## (map <- get_googlemap(c(-97.14667, 31.5493))) ggmap(map) # plotting based on a colloquial name # this requires a geocode() call, and needs that API get_googlemap("waco, texas") %>% ggmap() # different maptypes are available get_googlemap("waco, texas", maptype = "satellite") %>% ggmap() get_googlemap("waco, texas", maptype = "hybrid") %>% ggmap() # you can get the url as follows # see ?register_google if you want the key printed get_googlemap(urlonly = TRUE) ## other usage ######################################## # markers and paths are easy to access d <- function(x=-95.36, y=29.76, n,r,a){ round(data.frame( lon = jitter(rep(x,n), amount = a), lat = jitter(rep(y,n), amount = a) ), digits = r) } (df <- d(n = 50, r = 3, a = .3)) map <- get_googlemap(markers = df, path = df, scale = 2) ggmap(map) ggmap(map, extent = "device") + geom_point(aes(x = lon, y = lat), data = df, size = 3, colour = "black") + geom_path(aes(x = lon, y = lat), data = df) gc <- geocode("waco, texas", source = "google") center <- as.numeric(gc) ggmap(get_googlemap(center = center, color = "bw", scale = 2), extent = "device") # the scale argument can be seen in the following # (make your graphics device as large as possible) ggmap(get_googlemap(center, scale = 1), extent = "panel") # pixelated ggmap(get_googlemap(center, scale = 2), extent = "panel") # fine # archiving; note that you must meet google's terms for this condition map <- get_googlemap(archiving = TRUE) map <- get_googlemap() map <- get_googlemap() ggmap(map) # style map <- get_googlemap( maptype = "roadmap", style = c(feature = "all", element = "labels", visibility = "off"), color = "bw" ) ggmap(map) ## End(Not run)
https://developers.google.com/maps/documentation/maps-static/overview/, https://developers.google.com/maps/documentation/maps-static/start/, https://developers.google.com/maps/documentation/maps-static/get-api-key/, https://developers.google.com/maps/documentation/maps-static/usage-and-billing/, ggmap(), register_google()
David Kahle david@kahle.io