GetMapTiles: download map tiles from specified map tile servers such as openstreetmap or Google

Description

Query the server for map tiles, defined uniquely by their

X and Y ID and zoom. For offline usage, these map tiles are stored in a local directory

Example OSM:http://a.tile.openstreetmap.org/10/549/335.png

Also see https://wiki.openstreetmap.org/wiki/Tile_servers

Example Google mobile: http://mt1.google.com/vt/lyrs=m&x=1325&y=3143&z=13

Example Google satellite: http://mt1.google.com/vt/lyrs=s&x=1325&y=3143&z=13

Usage

GetMapTiles(center = c(lat = 52.431635, lon = 13.194773), 

    lonR, latR, nTiles = c(3, 3), zoom = 13, type = c("google", 

        "google-m", "google-s", "osm", "osm-hot", "stamen-toner", 

        "stamen-terrain", "stamen-watercolor")[1], 

    urlBase = "http://mt1.google.com/vt/lyrs=m", tileDir = "/tmp/", 

    CheckExistingFiles = TRUE, TotalSleep = NULL, tileExt = ".png", 

    returnTiles = TRUE, verbose = 0)

Value

list with important information

Arguments

center: optional center (lat first,lon second )
lonR: longitude range
latR: latitude range
nTiles: number of tiles in x and y direction
zoom: Google maps zoom level.
type: choice of tile server
urlBase: tileserver URL, alternatives would be "http://a.tile.openstreetmap.org/", "http://tile.stamen.com/toner/","http://tile.stamen.com/watercolor/"
tileDir: map tiles can be stored in a local directory, e.g. "~/mapTiles/Google/"
CheckExistingFiles: logical, if TRUE check if files already exist and only download if not!
TotalSleep: overall time (in seconds) that one is willing to add in between downloads. This is intended to lower the risk of a server denial. If NULL no call to Sys.sleep is executed
tileExt: image type of tile
returnTiles: return tiles in a list?
verbose: level of verbosity

Author

Markus Loecher

Examples

Run this code



if (0){


  


  #OSM, Ireland


  xlim = c(-7, -3.5) 


  ylim = c(51.35, 55.35)


  Dublin = c(lon=-6.266155,lat=53.350140)


  DublinMerc = geosphere_mercator(Dublin)


  


  ir.osm <- GetMapTiles(lonR=xlim, latR=ylim, zoom=7, verbose=1,


                        type = "osm", tileDir= TRUE)


  map = plotOSM(ir.osm)


  par("usr")#A vector of the form c(x1, x2, y1, y2)


  points(map$bbox$upperLeft,col=2,pch=20)


  points(map$bbox$lowerRight,col=2,pch=20)


  


  points(DublinMerc, col =2, pch=1,cex=1.5)


  


  ir.stamenToner <- GetMapTiles(lonR=xlim, latR=ylim, zoom=7,verbose=0,


                                type = "stamen", tileDir= TRUE)


  plotOSM(ir.stamenToner)


  


  ir.stamenWater <- GetMapTiles(lonR=xlim, latR=ylim, zoom=7, verbose=1,


                                type = "stamen-watercolor", tileDir= TRUE)


  plotOSM(ir.stamenWater)


 


  


  #############################################


  zoom=5


  nTiles = prod(NumTiles(lonR=c(-135,-66), latR=c(25,54) , zoom=zoom))


  us_google_5 = GetMapTiles(lonR=c(-135,-66), latR=c(25,54) , zoom=zoom, TotalSleep = 2*nTiles,


              type = "google", tileDir= TRUE, verbose = TRUE)


  


  PlotOnMapTiles(us_google_5)


  wtc_ll = getGeoCode("World Trade Center, NY")


  wtc_google_15=GetMapTiles(wtc_ll, zoom=15,nTiles = c(3,3), type = "google", 


                            tileDir= TRUE, verbose = 1)


  PlotOnMapTiles(wtc_google_15)


  wtc_google_16 =GetMapTiles(wtc_ll, zoom=16,nTiles = c(4,4), type = "google", 


                             tileDir= TRUE, verbose=1)


  PlotOnMapTiles(wtc_google_16)








  wtc_stamen=GetMapTiles(wtc_ll, zoom=15,nTiles = c(3,3), verbose=1,


                  type = "stamen-toner", tileDir= TRUE)


  PlotOnMapTiles(wtc_stamen)











###combine with leaflet:


#From:http://stackoverflow.com/questions/5050851/


#     best-lightweight-web-server-only-static-content-for-windows


#To use Python as a simple web server just change your working 


#directory to the folder with your static content and type 


#python -m SimpleHTTPServer 8000, everything in the directory


#will be available at http:/localhost:8000/


  


library(leaflet)


m = leaflet::leaflet() %>% 


  addTiles( urlTemplate = "http:/localhost:8000/mapTiles/OSM/{z}_{x}_{y}.png")


m = leaflet::leaflet() %>% 


  addTiles( urlTemplate = "http:/localhost:8000/mapTiles/Google/{z}_{x}_{y}.png")


m = m %>% leaflet::setView(-74.01312, 40.71180, zoom = 16)


m = m %>% leaflet::addMarkers(-74.01312, 40.71180)





#Quadriga:


m = m %>% leaflet::setView(13.39780, 52.51534, zoom = 16)


m = m %>% leaflet::addMarkers(13.39780, 52.51534)


}