ViewPoint.adjacent#

ViewPoint.adjacent() → list[Vertex]#

Vertices adjacent to this vertex

Returns:

the vertices at the far end of this vertex’s edges

Return type:

list of Vertex subclass

v.adjacent() is a list of the vertices that this vertex is joined to by an edge. “Adjacent” is the graph-theory term, and it is the relation that Graph.adjacency tabulates: row i of the adjacency matrix is non-zero exactly at the columns of the vertices returned by g[i].adjacent().

Note

  • For a directed graph these are the vertices at the head of the edges leaving this vertex, the successors.

  • There is one entry per edge, so a vertex joined by k parallel edges appears k times. In an undirected graph a self-loop lists the vertex itself twice, once for each end.

  • neighbours and neighbors are aliases, the same method under the British and American spellings, and are not deprecated.

>>> from pgraph import UGraph
>>> g = UGraph()
>>> v1 = g.add_vertex(coord=[0,0], name='v1')
>>> v2 = g.add_vertex(coord=[1,1], name='v2')
>>> v3 = g.add_vertex(coord=[2,2], name='v3')
>>> g.add_edge(v1, v2)
Edge{[v1] -- [v2], cost=1.414}
>>> g.add_edge(v1, v3)
Edge{[v1] -- [v3], cost=2.828}
>>> print(v1.adjacent())
[Vertex[v2, coord=(1, 1)], Vertex[v3, coord=(2, 2)]]
Seealso:

isadjacent successors predecessors incidences out_edges edges Graph.adjacency