41 lines
1.3 KiB
Python
41 lines
1.3 KiB
Python
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from networkx.utils import reverse_cuthill_mckee_ordering
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import networkx as nx
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def test_reverse_cuthill_mckee():
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# example graph from
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# http://www.boost.org/doc/libs/1_37_0/libs/graph/example/cuthill_mckee_ordering.cpp
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G = nx.Graph([(0, 3), (0, 5), (1, 2), (1, 4), (1, 6), (1, 9), (2, 3),
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(2, 4), (3, 5), (3, 8), (4, 6), (5, 6), (5, 7), (6, 7)])
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rcm = list(reverse_cuthill_mckee_ordering(G))
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assert rcm in [[0, 8, 5, 7, 3, 6, 2, 4, 1, 9],
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[0, 8, 5, 7, 3, 6, 4, 2, 1, 9]]
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def test_rcm_alternate_heuristic():
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# example from
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G = nx.Graph([(0, 0),
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(0, 4),
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(1, 1),
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(1, 2),
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(1, 5),
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(1, 7),
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(2, 2),
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(2, 4),
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(3, 3),
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(3, 6),
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(4, 4),
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(5, 5),
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(5, 7),
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(6, 6),
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(7, 7)])
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answers = [[6, 3, 5, 7, 1, 2, 4, 0], [6, 3, 7, 5, 1, 2, 4, 0],
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[7, 5, 1, 2, 4, 0, 6, 3]]
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def smallest_degree(G):
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deg, node = min((d, n) for n, d in G.degree())
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return node
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rcm = list(reverse_cuthill_mckee_ordering(G, heuristic=smallest_degree))
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assert rcm in answers
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