code: def lonlat_to_screen(self, lon, lat):
          
          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
docs: Projects geodesic coordinates to screen
          :param lon: longitude
          :param lat: latitude
          :return: x,y screen coordinates