def matrix_height(self, zoom):
        """
        Tile matrix height (number of rows) at zoom level.

        - zoom: zoom level
        """
        validate_zoom(zoom)
        height = int(math.ceil(self.grid.shape.height * 2**(zoom) / self.metatiling))
        return 1 if height < 1 else height
Tile matrix height (number of rows) at zoom level.

        - zoom: zoom level