public static double tile2lat(int y,int z){
  double n=Math.PI - (2.0 * Math.PI * y) / Math.pow(2.0,z);
  return Math.toDegrees(Math.atan(Math.sinh(n)));
}

public static double tile2lat ( int y , int z ) { double n = Math . PI - ( 2.0 * Math . PI * y ) / Math . pow ( 2.0 , z ) ; return Math . toDegrees ( Math . atan ( Math . sinh ( n ) ) ) ; }
returns the longitude for an y tile
