Set operations

pygeos.set_operations.coverage_union(a, b, **kwargs)

Merges multiple polygons into one. This is an optimized version of union which assumes the polygons to be non-overlapping.

Requires at least GEOS 3.8.0.

Parameters

a : Geometry or array_like

b : Geometry or array_like

See also

coverage_union_all

Examples

>>> from pygeos.constructive import normalize
>>> polygon = Geometry("POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))")
>>> normalize(coverage_union(polygon, Geometry("POLYGON ((1 0, 1 1, 2 1, 2 0, 1 0))")))
<pygeos.Geometry POLYGON ((0 0, 0 1, 1 1, 2 1, 2 0, 1 0, 0 0))>

Union with None returns same polygon >>> normalize(coverage_union(polygon, None)) <pygeos.Geometry POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))>

pygeos.set_operations.coverage_union_all(geometries, axis=0, **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.

Requires at least GEOS 3.8.0.

Parameters

geometries : array_like

axis : int

Axis along which the operation is performed. The default (zero) performs the operation over the first dimension of the input array. axis may be negative, in which case it counts from the last to the first axis.

See also

coverage_union

Examples

>>> from pygeos.constructive import normalize
>>> polygon_1 = Geometry("POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))")
>>> polygon_2 = Geometry("POLYGON ((1 0, 1 1, 2 1, 2 0, 1 0))")
>>> normalize(coverage_union_all([polygon_1, polygon_2]))
<pygeos.Geometry POLYGON ((0 0, 0 1, 1 1, 2 1, 2 0, 1 0, 0 0))>

pygeos.set_operations.difference(a, b, **kwargs)

Returns the part of geometry A that does not intersect with geometry B.

Parameters

a : Geometry or array_like

b : Geometry or array_like

Examples

>>> line = Geometry("LINESTRING (0 0, 2 2)")
>>> difference(line, Geometry("LINESTRING (1 1, 3 3)"))
<pygeos.Geometry LINESTRING (0 0, 1 1)>
>>> difference(line, Geometry("LINESTRING EMPTY"))
<pygeos.Geometry LINESTRING (0 0, 2 2)>
>>> difference(line, None) is None
True

pygeos.set_operations.intersection(a, b, **kwargs)

Returns the geometry that is shared between input geometries.

Parameters

a : Geometry or array_like

b : Geometry or array_like

See also

intersection_all

Examples

>>> line = Geometry("LINESTRING(0 0, 2 2)")
>>> intersection(line, Geometry("LINESTRING(1 1, 3 3)"))
<pygeos.Geometry LINESTRING (1 1, 2 2)>

pygeos.set_operations.intersection_all(geometries, axis=0, **kwargs)

Returns the intersection of multiple geometries.

Parameters

geometries : array_like

axis : int

Axis along which the operation is performed. The default (zero) performs the operation over the first dimension of the input array. axis may be negative, in which case it counts from the last to the first axis.

See also

intersection

Examples

>>> line_1 = Geometry("LINESTRING(0 0, 2 2)")
>>> line_2 = Geometry("LINESTRING(1 1, 3 3)")
>>> intersection_all([line_1, line_2])
<pygeos.Geometry LINESTRING (1 1, 2 2)>
>>> intersection_all([[line_1, line_2, None]], axis=1).tolist()
[None]

pygeos.set_operations.symmetric_difference(a, b, **kwargs)

Returns the geometry that represents the portions of input geometries that do not intersect.

Parameters

a : Geometry or array_like

b : Geometry or array_like

See also

symmetric_difference_all

Examples

>>> line = Geometry("LINESTRING(0 0, 2 2)")
>>> symmetric_difference(line, Geometry("LINESTRING(1 1, 3 3)"))
<pygeos.Geometry MULTILINESTRING ((0 0, 1 1), (2 2, 3 3))>

pygeos.set_operations.symmetric_difference_all(geometries, axis=0, **kwargs)

Returns the symmetric difference of multiple geometries.

Parameters

geometries : array_like

axis : int

Axis along which the operation is performed. The default (zero) performs the operation over the first dimension of the input array. axis may be negative, in which case it counts from the last to the first axis.

See also

symmetric_difference

Examples

>>> line_1 = Geometry("LINESTRING(0 0, 2 2)")
>>> line_2 = Geometry("LINESTRING(1 1, 3 3)")
>>> symmetric_difference_all([line_1, line_2])
<pygeos.Geometry MULTILINESTRING ((0 0, 1 1), (2 2, 3 3))>
>>> symmetric_difference_all([[line_1, line_2, None]], axis=1).tolist()
[None]

pygeos.set_operations.union(a, b, **kwargs)

Merges geometries into one.

Parameters

a : Geometry or array_like

b : Geometry or array_like

See also

union_all

Examples

>>> line = Geometry("LINESTRING(0 0, 2 2)")
>>> union(line, Geometry("LINESTRING(2 2, 3 3)"))
<pygeos.Geometry MULTILINESTRING ((0 0, 2 2), (2 2, 3 3))>
>>> union(line, None) is None
True

pygeos.set_operations.union_all(geometries, axis=0, **kwargs)

Returns the union of multiple geometries.

Parameters

geometries : array_like

axis : int

Axis along which the operation is performed. The default (zero) performs the operation over the first dimension of the input array. axis may be negative, in which case it counts from the last to the first axis.

See also

union

Examples

>>> line_1 = Geometry("LINESTRING(0 0, 2 2)")
>>> line_2 = Geometry("LINESTRING(2 2, 3 3)")
>>> union_all([line_1, line_2])
<pygeos.Geometry MULTILINESTRING ((0 0, 2 2), (2 2, 3 3))>
>>> union_all([[line_1, line_2, None]], axis=1).tolist()
[<pygeos.Geometry MULTILINESTRING ((0 0, 2 2), (2 2, 3 3))>]