GetMap.bbox: GetMap bbox

In RgoogleMaps: Overlays on Static Maps

GetMap bbox

Description

Wrapper function for GetMap. Query the Google server for a static map tile, defined primarily by its lat/lon range and/or center and/or zoom.

Multiple additional arguments allow the user to customize the map tile.

Usage

GetMap.bbox(lonR, latR, center, size = c(640, 640), 


    destfile = "MyTile.png", MINIMUMSIZE = FALSE, RETURNIMAGE = TRUE, 


    GRAYSCALE = FALSE, NEWMAP = TRUE, zoom, verbose = 0, 


    SCALE = 1, type = c("google", "google-m", "google-s", 


        "osm", "osm-hot", "stamen-toner", "stamen-terrain", 


        "stamen-watercolor")[1], urlBase = "http://mt1.google.com/vt/lyrs=m", 


    tileDir = "/tmp/", ...)

Arguments

lonR	longitude range
latR	latitude range
center	optional center
size	desired size of the map tile image. defaults to maximum size returned by the Gogle server, which is 640x640 pixels
destfile	File to load the map image from or save to, depending on NEWMAP.
MINIMUMSIZE	reduce the size of the map to its minimum size that still fits the lat/lon ranges ?
RETURNIMAGE	return image yes/no default: TRUE
GRAYSCALE	Boolean toggle; if TRUE the colored map tile is rendered into a black & white image, see RGB2GRAY
NEWMAP	if TRUE, query the Google server and save to destfile, if FALSE load from destfile.
zoom	Google maps zoom level. optional
verbose	level of verbosity
SCALE	use the API's scale parameter to return higher-resolution map images. The scale value is multiplied with the size to determine the actual output size of the image in pixels, without changing the coverage area of the map
type	choice of tile server
urlBase	tileserver URL, alternatives would be "http://a.tile.openstreetmap.org/", "http://tile.stamen.com/toner/","http://tile.stamen.com/watercolor/"
tileDir	map tiles can be stored in a local directory, e.g. "~/mapTiles/Google/"
...	extra arguments to GetMap

Value

map tile

Author(s)

Markus Loecher

Examples

 if (0){


 	mymarkers <- cbind.data.frame(lat = c(38.898648,38.889112, 38.880940), 


          lon = c(-77.037692, -77.050273, -77.03660), size =  c('tiny','tiny','tiny'), 


          col = c('blue', 'green', 'red'), char = c('','',''));





	##get the bounding box:


  	bb <- qbbox(lat = mymarkers[,"lat"], lon = mymarkers[,"lon"]);


  


	##download the map:


  	MyMap <- GetMap.bbox(bb$lonR, bb$latR, destfile = "DC.png", GRAYSCALE =TRUE,


                markers = mymarkers);


 	##The function qbbox() basically computes a bounding box for the given lat,lon 


   #points with a few additional options such as quantile boxes, additional buffers, etc.  


  	bb <- qbbox(c(40.702147,40.711614,40.718217),c(-74.015794,-74.012318,-73.998284), 


            TYPE = "all", margin = list(m=rep(5,4), TYPE = c("perc", "abs")[1]));


 	##download the map:           


	MyMap <- GetMap.bbox(bb$lonR, bb$latR,destfile = "MyTile3.png", maptype = "satellite") 





}

RgoogleMaps documentation built on Nov. 6, 2023, 5:08 p.m.