64 lines
1.4 KiB
Python
64 lines
1.4 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(
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[
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(0, 3),
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(0, 5),
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(1, 2),
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(1, 4),
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(1, 6),
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(1, 9),
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(2, 3),
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(2, 4),
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(3, 5),
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(3, 8),
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(4, 6),
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(5, 6),
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(5, 7),
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(6, 7),
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]
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)
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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], [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(
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[
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(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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]
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)
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answers = [
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[6, 3, 5, 7, 1, 2, 4, 0],
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[6, 3, 7, 5, 1, 2, 4, 0],
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[7, 5, 1, 2, 4, 0, 6, 3],
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]
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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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