shapely.coverage_union_all#
- coverage_union_all(geometries, axis=None, **kwargs)#
Returns the union of multiple polygons of a geometry collection. This is an optimized version of union which assumes the polygons to be non-overlapping.
Note
‘coverage_union_all’ requires at least GEOS 3.8.0.
This function ignores None values when other Geometry elements are present. If all elements of the given axis are None, an empty MultiPolygon is returned.
- Parameters:
- geometriesarray_like
- axisint, optional
Axis along which the operation is performed. The default (None) performs the operation over all axes, returning a scalar value. Axis may be negative, in which case it counts from the last to the first axis.
- **kwargs
See NumPy ufunc docs for other keyword arguments.
See also
Examples
>>> from shapely import normalize, Polygon >>> polygon_1 = Polygon([(0, 0), (0, 1), (1, 1), (1, 0), (0, 0)]) >>> polygon_2 = Polygon([(1, 0), (1, 1), (2, 1), (2, 0), (1, 0)]) >>> normalize(coverage_union_all([polygon_1, polygon_2])) <POLYGON ((0 0, 0 1, 1 1, 2 1, 2 0, 1 0, 0 0))> >>> normalize(coverage_union_all([polygon_1, None])) <POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))> >>> normalize(coverage_union_all([None, None])) <MULTIPOLYGON EMPTY>