Projects geodesic coordinates to screen
        :param lon: longitude
        :param lat: latitude
        :return: x,y screen coordinates

def lonlat_to_screen(self, lon, lat):
        """
        Projects geodesic coordinates to screen
        :param lon: longitude
        :param lat: latitude
        :return: x,y screen coordinates
        """
        if type(lon) == list:
            lon = np.array(lon)
        if type(lat) == list:
            lat = np.array(lat)

        lat_rad = np.radians(lat)
        n = 2.0 ** self.zoom
        xtile = (lon + 180.0) / 360.0 * n
        ytile = (1.0 - np.log(np.tan(lat_rad) + (1 / np.cos(lat_rad))) / math.pi) / 2.0 * n
        x = (xtile * TILE_SIZE).astype(int)
        y = (SCREEN_H - ytile * TILE_SIZE).astype(int)
        return x, y