get static Map from the Google server
MapBackground(lat, lon, destfile, NEWMAP = TRUE, myTile, zoom = NULL,
size = c(640, 640), GRAYSCALE = FALSE, mar = c(0, 0, 0, 0),
PLOT = FALSE, verbose = 1, ...)
File to load the map image from or save to, depending on NEWMAP.
if TRUE, query the Google server and save to destfile, if FALSE load from destfile.
map tile from previous downloads
Google maps zoom level.
desired size of the map tile image. defaults to maximum size returned by the Gogle server, which is 640x640 pixels
Boolean toggle; if TRUE the colored map tile is rendered into a black & white image, see RGB2GRAY
outer margin in plot; if you want to see axes, change the default
if TRUE, leave the plotting to PlotOnStaticMap, highly recommended
level of verbosity
further arguments to be passed to GetMap.bbox
list containing the map tile