R: overlays plot on background image of map tile

PlotOnStaticMap {RgoogleMaps} | R Documentation

## 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:

      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)

[Package RgoogleMaps version 1.4.1 Index]