pointpats.Window¶

class pointpats.Window(parts, holes=[])[source]¶

Geometric container for point patterns.

A window is used to define the area over which the pattern is observed. This area is used in estimating the intensity of the point pattern. See PointPattern.lambda_window.

Parameters:

parts: sequence: A sequence of rings which bound the positive space point pattern.
holes: sequence: A sequence of rings which bound holes in the polygons that bound the point pattern.

__init__(parts, holes=[])[source]¶

Methods

`__init__`(parts[, holes])
`build_quad_tree_structure`()	Build the quad tree structure for this polygon.
`contains_point`(point)	Test if a polygon contains a point.
`filter_contained`(points)

Attributes

`area`	Returns the area of the polygon.
`bbox`	Returns the bounding box of the polygon as a list.
`bounding_box`	Returns the bounding box of the polygon.
`centroid`	Returns the centroid of the polygon.
`holes`	Returns the holes of the polygon in clockwise order.
`len`	Returns the number of vertices in the polygon.
`parts`	Returns the parts of the polygon in clockwise order.
`perimeter`	Returns the perimeter of the polygon.
`vertices`	Returns the vertices of the polygon in clockwise order.

property area: float¶

Returns the area of the polygon.

Examples

>>> p = Polygon([Point((0, 0)), Point((1, 0)), Point((1, 1)), Point((0, 1))])
>>> p.area
1.0

>>> p = Polygon(
...     [Point((0, 0)), Point((10, 0)), Point((10, 10)), Point((0, 10))],
...     [Point((2, 1)), Point((2, 2)), Point((1, 2)), Point((1, 1))]
... )
>>> p.area
99.0

property bbox¶

Returns the bounding box of the polygon as a list.

Returns:

self._bboxlist: The bounding box of the polygon as a list.

See also

libpysal.cg.bounding_box

property bounding_box¶

Returns the bounding box of the polygon.

Returns:

self._bounding_boxlibpysal.cg.Rectangle: The bounding box of the polygon.

Examples

>>> p = Polygon([Point((0, 0)), Point((2, 0)), Point((2, 1)), Point((0, 1))])
>>> p.bounding_box.left
0.0

>>> p.bounding_box.lower
0.0

>>> p.bounding_box.right
2.0

>>> p.bounding_box.upper
1.0

build_quad_tree_structure()¶: Build the quad tree structure for this polygon. Once the structure is built, speed for testing if a point is inside the ring will be increased significantly.

property centroid: tuple¶

Returns the centroid of the polygon.

Notes

The centroid returned by this method is the geometric centroid and respects multipart polygons with holes. Also known as the ‘center of gravity’ or ‘center of mass’.

Examples

>>> p = Polygon(
...     [Point((0, 0)), Point((10, 0)), Point((10, 10)), Point((0, 10))],
...     [Point((1, 1)), Point((1, 2)), Point((2, 2)), Point((2, 1))]
... )
>>> p.centroid
(5.0353535353535355, 5.0353535353535355)

contains_point(point)¶

Test if a polygon contains a point.

Parameters:

pointlibpysal.cg.Point: A point to test for containment.

Returns:

containsbool: True if the polygon contains point otherwise False.

Notes

Points falling exactly on polygon edges may yield unpredictable results.

Examples

>>> p = Polygon(
...     [Point((0,0)), Point((4,0)), Point((4,5)), Point((2,3)), Point((0,5))]
... )
>>> p.contains_point((3,3))
1

>>> p.contains_point((0,6))
0

>>> p.contains_point((2,2.9))
1

>>> p.contains_point((4,5))
0

>>> p.contains_point((4,0))
0

Handles holes.

>>> p = Polygon(
...     [Point((0, 0)), Point((0, 10)), Point((10, 10)), Point((10, 0))],
...     [Point((2, 2)), Point((4, 2)), Point((4, 4)), Point((2, 4))]
... )
>>> p.contains_point((3.0, 3.0))
False

>>> p.contains_point((1.0, 1.0))
True

filter_contained(points)[source]¶

property holes: list¶

Returns the holes of the polygon in clockwise order.

Examples

>>> p = Polygon(
...     [Point((0, 0)), Point((10, 0)), Point((10, 10)), Point((0, 10))],
...     [Point((1, 2)), Point((2, 2)), Point((2, 1)), Point((1, 1))]
... )
>>> len(p.holes)
1

property len: int¶

Returns the number of vertices in the polygon.

Examples

>>> p1 = Polygon([Point((0, 0)), Point((0, 1)), Point((1, 1)), Point((1, 0))])
>>> p1.len
4

>>> len(p1)
4

property parts: list¶

Returns the parts of the polygon in clockwise order.

Examples

>>> p = Polygon(
...     [
...         [Point((0, 0)), Point((1, 0)), Point((1, 1)), Point((0, 1))],
...         [Point((2, 1)), Point((2, 2)), Point((1, 2)), Point((1, 1))]
...     ]
... )
>>> len(p.parts)
2

property perimeter: int | float¶

Returns the perimeter of the polygon.

Examples

>>> p = Polygon([Point((0, 0)), Point((1, 0)), Point((1, 1)), Point((0, 1))])
>>> p.perimeter
4.0

property vertices: list¶

Returns the vertices of the polygon in clockwise order.

Examples

>>> p1 = Polygon([Point((0, 0)), Point((0, 1)), Point((1, 1)), Point((1, 0))])
>>> len(p1.vertices)
4