GetOsmMap: Query the Open Street Map server for map tiles instead of...

In RgoogleMaps: Overlays on Static Maps

Description

The querying parameters for Open Street Maps are somewhat different in this version.

Instead of a zoom, center and size, the user supplies a scale parameter and a lat/lon bounding box.

The scale determines the image size.

Usage

GetOsmMap(lonR = c(-74.02132, -73.98622), latR = c(40.69983, 


    40.72595), scale = 20000, destfile = "MyTile.png", format = "png", 


    RETURNIMAGE = TRUE, GRAYSCALE = FALSE, NEWMAP = TRUE, verbose = 1, 


    ...)

Arguments

lonR	longitude range
latR	latitude range
scale	Open Street map scale parameter. The larger this value, the smaller the resulting map tile in memory. There is a balance to be struck between the lat/lon bounding box and the scale parameter.
destfile	File to load the map image from or save to, depending on NEWMAP.
format	(optional) defines the format of the resulting image.
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.
verbose	level of verbosity,
...	extra arguments to be used in future versions

Value

map structure or URL used to download the tile.

Note

The OSM maptile server is frequently too busy to accomodate every request, so patience is warranted.

Author(s)

Markus Loecher

Examples

if (interactive()) {


 	CologneMap <- GetOsmMap(lonR= c(6.89, 7.09), latR = c(50.87, 51), scale = 150000, 


                            destfile = "Cologne.png");


	PlotOnStaticMap(CologneMap, mar=rep(4,4), NEWMAP = FALSE, TrueProj = FALSE, axes= TRUE);


		


	PrincetonMap <- GetOsmMap(lonR= c(-74.67102, -74.63943), latR = c(40.33804,40.3556), 


                             scale = 12500, destfile = "Princeton.png");


	png("PrincetonWithAxes.png", 1004, 732)


      PlotOnStaticMap(PrincetonMap, axes = TRUE, mar = rep(4,4));


    dev.off()


 }

RgoogleMaps documentation built on May 2, 2019, 5:03 p.m.