PlotOnStaticMap
is used like this:
PlotOnStaticMap(MyMap, lat, lon, destfile, zoom = NULL, size = c(640,
640), GRAYSCALE = FALSE, add = FALSE, FUN = points, mar = c(0,
0, 0, 0), NEWMAP = TRUE, TrueProj = TRUE, axes = FALSE, verbose = 0, ...)
MyMap = optional map object
lat = latitude values to be overlaid
lon = longitude values to be overlaid
destfile = File to load the map image from or save to, depending on whether MyMap was passed.
zoom = Google maps zoom level. optional if MyMap is passed, required if not.
size = desired size of the map tile image. Defaults to maximum size returned by the Google server, which is 640x640 pixels
GRAYSCALE = Boolean toggle; if TRUE the colored map tile is rendered into a black & white image, see RGB2GRAY
add = start a new plot or add to an existing
FUN = plotting function to use for overlay; typical choices would be points and lines
mar = outer margin in plot; if you want to see axes, change the default
NEWMAP = load map from file or get it "new" from the static map server
TrueProj = set to FALSE if you are willing to accept some degree of inaccuracy in the mapping. In that case, the coordinates of the image are in lat/lon and the user can simply overly points/lines/axis without worrying about projections