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

Details

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

Value

list with X and Y pixel values

Author(s)

Markus Loecher

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);