NumTiles function

computes the necessary number of tiles from a bounding box and a zoom level

NumTiles(lonR, latR, zoom = 13, CheckExistingFiles = TRUE, 
    tileExt = ".png", tileDir = "~/mapTiles/OSM/", 
    verbose = 0)

Arguments

• lonR: longitude range
• latR: latitude range,
• zoom: zoom level
• CheckExistingFiles: logical, if TRUE check if files already exist and only download if not!
• tileExt: image type of tile
• tileDir: map tiles are stored in a local directory, e.g. "~/mapTiles/Google/"
• verbose: level of verbosity

Returns

tuple with number of tiles for lon and lat extent

Author(s)

Markus Loecher

Examples

if (0){
  #US bounding box:
  for (zoom in 4:15) {
    cat("OSM, zoom =", zoom, "\n")
    NumTiles(lonR=c(-135,-66), latR=c(25,54) , zoom=zoom)
  }
  for (zoom in 4:15) {
    cat("Google, zoom =", zoom, "\n")
    NumTiles(lonR=c(-135,-66), latR=c(25,54) , zoom=zoom, tileDir= "~/mapTiles/Google/")
  }
}