RgoogleMaps (version 1.2.0.7)

LatLon2XY: computes the coordinate transformation from lat/lon to map tile coordinates

Description

The function LatLon2XY(lat,lon,zoom) computes the coordinate transformation from lat/lon to map tile coordinates given a zoom level.

It returns the tile coordinates as well as the pixel coordinates within the Tile itself.

Thanks to Neil Young (see http://groups.google.com/group/Google-Maps-API/browse_thread/thread/d2103ac29e95696f?hl=en) for providing the formulae used.

Usage

LatLon2XY(lat, lon, zoom)

Arguments

lat

latitude values to transform

lon

longitude values to transform

zoom

zoom level.lat,lon,zoom

Value

Tile

integer numbers specifying the tile

Coords

pixel coordinate within the Tile

Examples

LatLon2XY(38.45, -122.375, 11)