PlotOnStaticMap: overlays plot on background image of map tile

In RgoogleMaps: Overlays on Static Maps

overlays plot on background image of map tile

Description

This function is the workhorse of the package RgoogleMaps. It overlays plot on background image of map tile

Usage

PlotOnStaticMap(MyMap, lat, lon, destfile, zoom = NULL, 


    size, GRAYSCALE = FALSE, add = FALSE, FUN = points, 


    mar = c(0, 0, 0, 0), NEWMAP = TRUE, TrueProj = TRUE, 


    axes = FALSE, atX = NULL, atY = NULL, verbose = 0, 


    ...)

Arguments

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 Gogle 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
axes	overlay axes ?
atX	numeric; position of ticks on x-axis; if missing, axTicks is called for nice values; see axis
atY	numeric; position of ticks on y-axis; if missing, axTicks is called for nice values; see axis
verbose	level of verbosity
...	further arguments to be passed to FUN

Value

the map object is returned via invisible(MyMap)

Author(s)

Markus Loecher

Examples

#The first step naturally will be to download a static map from the Google server. A simple example:





  if (0){


    lat = c(40.702147,40.711614,40.718217);


    lon = c(-74.015794,-74.012318,-73.998284);


    center = c(mean(lat), mean(lon));


    zoom <- min(MaxZoom(range(lat), range(lon)));


    #this overhead is taken care of implicitly by GetMap.bbox();              


    MyMap <- GetMap(center=center, zoom=zoom,markers = paste0("&markers=color:blue|label:S|",


             "40.702147,-74.015794&markers=color:green|label:G|40.711614,-74.012318&markers=",


             "color:red|color:red|label:C|40.718217,-73.998284"), destfile = "MyTile1.png");


                   


     tmp <- PlotOnStaticMap(MyMap, lat = lat, 


                            lon = lon, 


                            destfile = "MyTile1.png", cex=1.5,pch=20,


                            col=c('red', 'blue', 'green'), add=FALSE);


     #and add lines:


     PlotOnStaticMap(MyMap, lat = c(40.702147,40.711614,40.718217), 


                     lon = c(-74.015794,-74.012318,-73.998284), 


                     lwd=1.5,col=c('red', 'blue', 'green'), FUN = lines, add=TRUE)


     	


  }

RgoogleMaps documentation built on Nov. 6, 2023, 5:08 p.m.