def test_fundamental_cycle_basis_paton():
g = create_graph(
directed=False,
allowing_self_loops=False,
allowing_multiple_edges=False,
weighted=True,
)
g.add_vertices_from([0, 1, 2, 3, 4, 5])
g.add_edge(0, 1)
g.add_edge(1, 2)
g.add_edge(2, 3)
g.add_edge(3, 0)
g.add_edge(1, 4)
g.add_edge(4, 5)
g.add_edge(5, 2)
fcb_weight, fcb_it = cycles.fundamental_cycle_basis_paton(g)
assert fcb_weight == 8.0
cycle1 = next(fcb_it)
cycle2 = next(fcb_it)
with pytest.raises(StopIteration):
next(fcb_it)
assert cycle1.edges == [1, 2, 3, 0]
assert cycle2.edges == [4, 5, 6, 1]
def is_bridge(e, g):
if not (e in g.edges):
return None
w, c = fundamental_cycle_basis_paton(g)
return all(not e in cycle for cycle in c)