Tile2R: simple utility to offset and scale XY coordinates with...
In RgoogleMaps: Overlays on Static Maps

Description Usage Arguments Details Value Author(s) Examples

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

1	Tile2R(points, center)

`points`	XY coordinates returned by e.g. LatLon2XY
`center`	XY coordinates of center returned by e.g. LatLon2XY

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

list with X and Y pixel values

Markus Loecher

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);