libpysal.cg.Chain¶

class libpysal.cg.Chain(vertices)[source]¶

Geometric representation of a chain, also known as a polyline.

Examples

>>> c = Chain([Point((0, 0)), Point((1, 0)), Point((1, 1)), Point((2, 1))])

Create a chain from one ordered sequence of points or many parts.

Parameters:¶

vertices : list¶: A point list or list of point lists.

Attributes

`arclen`	Returns the geometric length of the chain computed using 'arcdistance' (meters).
`bounding_box`	Returns the bounding box of the chain.
`len`	Returns the geometric length of the chain.
`parts`	Returns the parts (lists of `libpysal.cg.Point` objects) of the chain.
`segments`	Returns the segments that compose the chain.
`vertices`	Returns the vertices of the chain in clockwise order.

property arclen : int | float[source]¶: Returns the geometric length of the chain computed using ‘arcdistance’ (meters).

property bounding_box[source]¶

Returns the bounding box of the chain.

Returns:¶: self._bounding_box – The bounding box of the chain.
Return type:¶: libpysal.cg.Rectangle

Examples

>>> c = Chain([Point((0, 0)), Point((2, 0)), Point((2, 1)), Point((0, 1))])
>>> c.bounding_box.left
0.0

>>> c.bounding_box.lower
0.0

>>> c.bounding_box.right
2.0

>>> c.bounding_box.upper
1.0

property len : int[source]¶

Returns the geometric length of the chain.

Examples

>>> c = Chain([Point((0, 0)), Point((1, 0)), Point((1, 1)), Point((2, 1))])
>>> c.len
3.0

>>> c = Chain(
...     [
...         [Point((0, 0)), Point((1, 0)), Point((1, 1))],
...         [Point((10, 10)), Point((11, 10)), Point((11, 11))]
...     ]
... )
>>> c.len
4.0

property parts : list[source]¶

Returns the parts (lists of libpysal.cg.Point objects) of the chain.

Examples

>>> c = Chain(
...     [
...         [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(c.parts)
2

property segments : list[source]¶: Returns the segments that compose the chain.

property vertices : list[source]¶

Returns the vertices of the chain in clockwise order.

Examples

>>> c = Chain([Point((0, 0)), Point((1, 0)), Point((1, 1)), Point((2, 1))])
>>> verts = c.vertices
>>> len(verts)
4