added ability to use tiles stored locally and included modified funct…

DESCRIPTION

@@ -1,14 +1,15 @@
-Package: ggmap
-Version: 2.7.900
+Package: ggmapAwhere
+Version: 2.7.900.1
 Title: Spatial Visualization with ggplot2
 Description: A collection of functions to visualize spatial data and models
     on top of static maps from various online sources (e.g Google Maps and Stamen
     Maps). It includes tools common to those tasks, including functions for
     geolocation and routing.
-URL: https://github.com/dkahle/ggmap
-BugReports: https://github.com/dkahle/ggmap/issues
-Authors@R: c(person("David", "Kahle", email = "david.kahle@gmail.com", role = c("aut", "cre"), comment = c(ORCID = "0000-0002-9999-1558")),
-  person("Hadley", "Wickham", email = "h.wickham@gmail.com", role = "aut", comment = c(ORCID = "0000-0003-4757-117X")))
+URL: https://github.com/aWhereAPI/ggmap
+BugReports: https://github.com/aWhereAPI/ggmap/issues
+Authors@R: c(person("Technical", "Support", ,"technicalsupport@awhere.com", role = c("ctb"))
+             person("David", "Kahle", email = "david.kahle@gmail.com", role = c("aut", "cre"))
+             person("Hadley", "Wickham", email = "h.wickham@gmail.com", role = "aut"))
 Depends:
     R (>= 3.1.0),
     ggplot2 (>= 2.2.0)

NAMESPACE

@@ -2,6 +2,7 @@
 
 S3method(print,ggmap)
 S3method(print,ggmap_credentials)
+export(GetMapTiles)
 export(LonLat2XY)
 export(OSM_scale_lookup)
 export(XY2LonLat)

R/GetMapTiles.R

@@ -0,0 +1,141 @@
+#' Download Map Tiles to local directory
+#'
+#' \code{GetMapTiles} is a smart wrapper that queries the Google Maps,
+#' OpenStreetMap, Stamen Maps or Naver Map servers for a map.  This download map
+#'  tiles from specified map tile servers such as openstreetmap or Google
+#'  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
+#'  THIS CODE WAS MODIFIED FROM THE FUNCTION IN THE RgoogleMaps Package
+#'
+#' @param bbox Extent over which to pull tiles
+#' @param zoom map zoom, an integer from 3 (continent) to 21
+#'   (building), default value 10 (city).  openstreetmaps limits a
+#'   zoom of 18, and the limit on stamen maps depends on the
+#'   maptype.  "auto" automatically determines the zoom for bounding
+#'   box specifications, and is defaulted to 10 with center/zoom
+#'   specifications.  maps of the whole world currently not
+#'   supported.
+#' @param urlBase path of tile server to query
+#' @param CheckExistingFiles will check if current tiles are already downloaded and skip if are
+#' @param 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 \link{Sys.sleep} is executed
+#' @param tileDir Where are local tiles stored.  Only relevant if doOffline == TRUE
+#' @param tileExt file extension of files from tile server
+#' @param verbose level of verbosity 
+#' @return a ggmap object (a classed raster object with a bounding
+#'   box attribute)
+#' @author David Kahle \email{david.kahle@@gmail.com}
+#' @seealso \code{\link{ggmap}}, \code{\link{GetMap}} in package
+#'   RgoogleMaps
+#' @export
+#' @examples GetMapTiles(zoom=9
+#'                       ,bbox = sbbox
+#'                       ,verbose=1
+#'                       ,urlBase = "http://tile.stamen.com/terrain/"
+#'                       ,tileDir= "./mapTiles/stamen/terrain/")
+
+GetMapTiles <- function(bbox = c(left = -95.80204
+                                 ,bottom = 29.38048
+                                 ,right = -94.92313
+                                 ,top = 30.14344)
+                        ,zoom =10 
+                        ,urlBase =  "http://tile.stamen.com/terrain/"
+                        ,CheckExistingFiles = TRUE 
+                        ,TotalSleep = NULL 
+                        ,tileExt = ".png" 
+                        ,tileDir= "~/mapTiles/stamen/" 
+                        ,verbose=0){
+
+
+  # tile2long = function(x,z){ return (x/(2^z)*360-180); }
+  # tile2lat= function(y,z) { n=pi-2*pi*y/(2^z);
+  #                           return (180/pi*atan(0.5*(exp(n)-exp(-n)))); }
+
+  lonR <- c(bbox['left'],bbox['right'])
+  latR <- c(bbox['bottom'],bbox['top'])
+
+  nTiles = c(0,0)
+
+  if (!missing(lonR) & !missing(latR)) {
+    XYmin = RgoogleMaps::LatLon2XY(lat=latR[1], lon=lonR[1],zoom=zoom)
+    XYmax = RgoogleMaps::LatLon2XY(lat=latR[2], lon=lonR[2],zoom=zoom)
+    nTiles[1] = abs(XYmax$Tile[1,1]-XYmin$Tile[1,1])+1
+    nTiles[2] = abs(XYmax$Tile[1,2]-XYmin$Tile[1,2])+1
+
+    center = c(lat=mean(latR),lon=mean(lonR))
+
+    if (verbose){
+      cat("nTiles=",nTiles,", center=", round(center,3), "\n")
+    }
+  } 
+
+  XY = RgoogleMaps::LatLon2XY(lat=center["lat"], lon=center["lon"],zoom=zoom)
+  tileXY = XY$Tile + as.numeric(XY$Coords > 256)
+
+  if (nTiles[1] %% 2 == 0) {#even
+    X = (tileXY[1,1]-nTiles[1]/2):(tileXY[1,1]+nTiles[1]/2-1);
+  } else {
+    X = (tileXY[1,1]-(nTiles[1]-1)/2):(tileXY[1,1]+(nTiles[1]-1)/2);
+  }
+  if (nTiles[2] %% 2 == 0) {#even
+    Y = (tileXY[1,2]-nTiles[2]/2):(tileXY[1,2]+nTiles[2]/2-1);
+  } else {
+    Y = (tileXY[1,2]-(nTiles[2]-1)/2):(tileXY[1,2]+(nTiles[2]-1)/2);
+  }
+
+  if (!dir.exists(tileDir)) {
+    if (verbose) cat("trying to create dir",tileDir, "\n")
+    dir.create(tileDir, recursive = TRUE)
+  }
+  if (CheckExistingFiles) ExistingFiles=list.files(path=tileDir)
+
+  NumTiles = length(X)*length(Y)
+  if (verbose) cat (NumTiles, "tiles to download \n")
+
+  DOWNLOAD=TRUE
+  k=1
+  tiles=list()
+  y = 0
+
+  for (x_count in 1:length(X)){
+
+    cat(paste0('Currently on tile ', ((x_count-1) * length(Y))+1,' of ',NumTiles,'\n'))
+
+    x <- X[x_count]
+
+    for (y_count in 1:length(Y)){
+
+      y <- Y[y_count]
+
+      if (grepl("openstreetmap",urlBase) | grepl("stamen",urlBase)){
+        url <- paste0(urlBase, zoom, "/",x , "/", y, ".png")
+      } else if (grepl("google",urlBase)){
+        url <- paste0(urlBase, "&x=", x, "&y=", y, "&z=", zoom)
+      } 
+
+      f=paste(zoom, x, y, sep="_")
+		  if (CheckExistingFiles) 
+        if (paste0(f,tileExt) %in% ExistingFiles) {
+          if (verbose) cat("     NOT downloading existing file ",f, tileExt, "\n",sep="" )
+          DOWNLOAD=FALSE
+        } else {
+          if (verbose) cat("     downloading file ",f, tileExt, "\n",sep="" )
+          DOWNLOAD=TRUE
+        }
+      destfile = file.path(tileDir, f)
+      mapFile=paste0(destfile,tileExt)
+
+      if (DOWNLOAD){
+  		  if (!is.null(TotalSleep)){
+  		    Sys.sleep(round(runif(1,max=2*TotalSleep/NumTiles),1))
+  		  }
+  		  try(download.file(url, mapFile, mode="wb", quiet = TRUE));
+      }
+		  k=k+1
+    }
+  }
+  mt = list(X=X,Y=Y,zoom=zoom,tileDir=tileDir,tileExt=tileExt,tiles=tiles)
+  class(mt) =  "mapTiles"
+  invisible(mt)	
+}

R/get_map.R

@@ -32,6 +32,9 @@
 #' @param color color ("color") or black-and-white ("bw")
 #' @param language language for google maps
 #' @param api_key an api key for cloudmade maps
+#' @param doOffline Should map tiles be loaded from local directory.
+#'    Must be downloaded first
+#' @param tileDir Where are local tiles stored.  Only relevant if doOffline == TRUE
 #' @return a ggmap object (a classed raster object with a bounding
 #'   box attribute)
 #' @author David Kahle \email{david.kahle@@gmail.com}
@@ -57,18 +60,39 @@
 #' ggmap(map, fullpage = TRUE)
 #'
 #' }
-get_map <- function(
-  location = c(lon = -95.3632715, lat = 29.7632836), zoom = "auto", scale = "auto",
-  maptype = c("terrain", "terrain-background", "satellite", "roadmap",
-    "hybrid", "toner", "watercolor", "terrain-labels",
-    "terrain-lines", "toner-2010", "toner-2011", "toner-background",
-    "toner-hybrid", "toner-labels", "toner-lines", "toner-lite"),
-  source = c("google","osm","stamen","cloudmade"),
-  force = ifelse(source == "google", TRUE, TRUE), messaging = FALSE, urlonly = FALSE,
-  filename = NULL,
-  crop = TRUE, color = c("color","bw"), language = "en-EN",
-  api_key
-){
+get_map <- function(location = c(lon = -95.3632715, lat = 29.7632836)
+                    ,zoom = "auto"
+                    ,scale = "auto"
+                    ,maptype = c("terrain"
+                                 ,"terrain-background"
+                                 ,"satellite", "roadmap"
+                                 ,"hybrid",
+                                 ,"toner"
+                                 ,"watercolor"
+                                 ,"terrain-labels"
+                                 ,"terrain-lines"
+                                 ,"toner-2010"
+                                 ,"toner-2011"
+                                 ,"toner-background"
+                                 ,"toner-hybrid"
+                                 ,"toner-labels"
+                                 ,"toner-lines"
+                                 ,"toner-lite")
+                    ,source = c("google","osm","stamen","cloudmade")
+                    ,force = ifelse(source == "google", TRUE, TRUE)
+                    ,messaging = FALSE
+                    ,urlonly = FALSE
+                    ,filename = NULL
+                    ,crop = TRUE
+                    ,color = c("color","bw")
+                    ,language = "en-EN"
+                    ,api_key
+                    ,doOffline = FALSE
+                    ,tileDir = './mapTiles'){
+
+  if (doOffline == TRUE & !(maptype %in% c('terrain','toner')) & source == 'stamen') {
+    stop('Offline Mode only works for Stamen Terrain and Toner maps currently')
+  }
 
   # deprecated syntaxes
   args <- as.list(match.call(expand.dots = TRUE)[-1])
@@ -184,6 +208,13 @@ get_map <- function(
     zoom = 10
   }
 
+  maxZoomDownloaded <- 13
+
+  if (doOffline == TRUE & zoom > maxZoomDownloaded) {
+    zoom <- maxZoomDownloaded
+  }
+
+
 
   # compute scale when scale = "auto" (only for google/osm)
   if(scale == "auto"){
@@ -273,9 +304,17 @@ get_map <- function(
 
   	# get map/return
     return(
-      get_stamenmap(bbox = location, zoom = zoom, maptype = maptype, crop = crop,
-        messaging = messaging, urlonly = urlonly, filename = filename, force = force,
-        color = color)
+      get_stamenmap(bbox = location
+                    ,zoom = zoom
+                    ,maptype = maptype
+                    ,crop = crop
+                    ,messaging = messaging
+                    ,urlonly = urlonly
+                    ,filename = filename
+                    ,force = force
+                    ,color = color
+                    ,doOffline = doOffline
+                    ,tileDir = tileDir)
     )
   }