is_arborescence

is_arborescence(G)

Returns True if G is an arborescence.

An arborescence is a directed tree with maximum in-degree equal to 1.

Parameters:

Ggraph

The graph to test.

Returns:

bbool

A boolean that is True if G is an arborescence.

See also

is_tree

Notes

In another convention, an arborescence is known as a tree.

Examples

>>> G = nx.DiGraph([(0, 1), (0, 2), (2, 3), (3, 4)])
>>> nx.is_arborescence(G)
True
>>> G.remove_edge(0, 1)
>>> G.add_edge(1, 2)  # maximum in-degree is 2
>>> nx.is_arborescence(G)
False