GetMap.bbox {RgoogleMaps} | R Documentation |
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.
GetMap.bbox(lonR, latR, center, size = c(640, 640), destfile = "MyTile.png", MINIMUMSIZE = FALSE, RETURNIMAGE = TRUE, GRAYSCALE = FALSE, NEWMAP = TRUE, zoom, verbose = 1, ...)
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 ? default: FALSE |
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 |
... |
extra arguments to GetMap |
map tile
To handle png file formats, you will need the package rgdal installed, for jpeg the package ReadImages.
Markus Loecher, Sense Networks <markus@sensenetworks.com>
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: ## Not run: MyMap <- GetMap.bbox(bb$lonR, bb$latR, destfile = "DC.png", GRAYSCALE =T, markers = mymarkers); ## End(Not run) #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: ## Not run: MyMap <- GetMap.bbox(bb$lonR, bb$latR,destfile = "MyTile3.png", maptype = "satellite")