RgoogleMaps (version 1.0)

Tile2R: simple utility to offset and scale XY coordinates with respect to the center

Description

simple utility to offset and scale XY coordinates with respect to the center

Usage

Tile2R(points, center)

Arguments

points

XY coordinates returned by e.g. LatLon2XY

center

XY coordinates of center returned by e.g. LatLon2XY

Value

• X
  X values of proper coordinate system
• Y
  Y values of proper coordinate system

Details

mainly used for shrinking the size of a tile to the minimum size.

Examples

latR <- c(34.5,34.9);
  lonR <- c(-100.3, -100);
  lat.center <- 34.7;
  lon.center <- -100.2;
  zoom = 10;
  ll <- LatLon2XY(latR[1], lonR[1], zoom);#lower left corner
  ur <- LatLon2XY(latR[2], lonR[2], zoom );#upper right corner
  cr <- LatLon2XY(lat.center, lon.center, zoom );#center
  ll.Rcoords <- Tile2R(ll, cr);
  ur.Rcoords <- Tile2R(ur, cr);