\name{LatLon2XY}

\alias{LatLon2XY}

\title{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 \url{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{

  \item{lat}{latitude values to transform}

  \item{lon}{longitude values to transform}

  \item{zoom}{zoom level.lat,lon,zoom}

}



\value{A list with values

\item{Tile}{integer numbers specifying the tile}

\item{Coords}{pixel coordinate within the Tile}}



\author{"Markus Loecher, Berlin School of Economics and Law (BSEL)" <markus.loecher@gmail.com>}

\note{The fractional part times 256 is the pixel coordinate within the Tile itself. }







\examples{

LatLon2XY(38.45, -122.375, 11)

}