GetMap.bbox {RgoogleMaps}R Documentation

download a static map from the Google server

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 = 1, ...)

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 ? 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

Value

map tile

Note

To handle png file formats, you will need the package rgdal installed, for jpeg the package ReadImages.

Author(s)

Markus Loecher, Sense Networks <markus@sensenetworks.com>

See Also

GetMap

Examples

  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") 


[Package RgoogleMaps version 1.1.3 Index]