160 lines
6.4 KiB
Python
160 lines
6.4 KiB
Python
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# test_boundary.py - unit tests for the boundary module
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#
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# Copyright 2015 NetworkX developers.
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#
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# This file is part of NetworkX.
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#
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# NetworkX is distributed under a BSD license; see LICENSE.txt for more
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# information.
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"""Unit tests for the :mod:`networkx.algorithms.boundary` module."""
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from itertools import combinations
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import networkx as nx
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from networkx.testing import almost_equal, assert_edges_equal
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from networkx import convert_node_labels_to_integers as cnlti
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class TestNodeBoundary(object):
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"""Unit tests for the :func:`~networkx.node_boundary` function."""
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def test_null_graph(self):
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"""Tests that the null graph has empty node boundaries."""
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null = nx.null_graph()
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assert nx.node_boundary(null, []) == set()
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assert nx.node_boundary(null, [], []) == set()
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assert nx.node_boundary(null, [1, 2, 3]) == set()
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assert nx.node_boundary(null, [1, 2, 3], [4, 5, 6]) == set()
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assert nx.node_boundary(null, [1, 2, 3], [3, 4, 5]) == set()
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def test_path_graph(self):
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P10 = cnlti(nx.path_graph(10), first_label=1)
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assert nx.node_boundary(P10, []) == set()
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assert nx.node_boundary(P10, [], []) == set()
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assert nx.node_boundary(P10, [1, 2, 3]) == {4}
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assert nx.node_boundary(P10, [4, 5, 6]) == {3, 7}
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assert nx.node_boundary(P10, [3, 4, 5, 6, 7]) == {2, 8}
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assert nx.node_boundary(P10, [8, 9, 10]) == {7}
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assert nx.node_boundary(P10, [4, 5, 6], [9, 10]) == set()
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def test_complete_graph(self):
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K10 = cnlti(nx.complete_graph(10), first_label=1)
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assert nx.node_boundary(K10, []) == set()
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assert nx.node_boundary(K10, [], []) == set()
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assert nx.node_boundary(K10, [1, 2, 3]) == {4, 5, 6, 7, 8, 9, 10}
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assert nx.node_boundary(K10, [4, 5, 6]) == {1, 2, 3, 7, 8, 9, 10}
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assert nx.node_boundary(K10, [3, 4, 5, 6, 7]) == {1, 2, 8, 9, 10}
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assert nx.node_boundary(K10, [4, 5, 6], []) == set()
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assert nx.node_boundary(K10, K10) == set()
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assert nx.node_boundary(K10, [1, 2, 3], [3, 4, 5]) == {4, 5}
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def test_petersen(self):
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"""Check boundaries in the petersen graph
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cheeger(G,k)=min(|bdy(S)|/|S| for |S|=k, 0<k<=|V(G)|/2)
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"""
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def cheeger(G, k):
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return min(len(nx.node_boundary(G, nn)) / k
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for nn in combinations(G, k))
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P = nx.petersen_graph()
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assert almost_equal(cheeger(P, 1), 3.00, places=2)
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assert almost_equal(cheeger(P, 2), 2.00, places=2)
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assert almost_equal(cheeger(P, 3), 1.67, places=2)
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assert almost_equal(cheeger(P, 4), 1.00, places=2)
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assert almost_equal(cheeger(P, 5), 0.80, places=2)
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def test_directed(self):
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"""Tests the node boundary of a directed graph."""
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G = nx.DiGraph([(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)])
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S = {0, 1}
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boundary = nx.node_boundary(G, S)
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expected = {2}
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assert boundary == expected
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def test_multigraph(self):
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"""Tests the node boundary of a multigraph."""
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G = nx.MultiGraph(list(nx.cycle_graph(5).edges()) * 2)
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S = {0, 1}
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boundary = nx.node_boundary(G, S)
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expected = {2, 4}
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assert boundary == expected
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def test_multidigraph(self):
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"""Tests the edge boundary of a multdiigraph."""
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edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)]
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G = nx.MultiDiGraph(edges * 2)
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S = {0, 1}
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boundary = nx.node_boundary(G, S)
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expected = {2}
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assert boundary == expected
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class TestEdgeBoundary(object):
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"""Unit tests for the :func:`~networkx.edge_boundary` function."""
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def test_null_graph(self):
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null = nx.null_graph()
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assert list(nx.edge_boundary(null, [])) == []
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assert list(nx.edge_boundary(null, [], [])) == []
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assert list(nx.edge_boundary(null, [1, 2, 3])) == []
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assert list(nx.edge_boundary(null, [1, 2, 3], [4, 5, 6])) == []
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assert list(nx.edge_boundary(null, [1, 2, 3], [3, 4, 5])) == []
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def test_path_graph(self):
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P10 = cnlti(nx.path_graph(10), first_label=1)
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assert list(nx.edge_boundary(P10, [])) == []
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assert list(nx.edge_boundary(P10, [], [])) == []
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assert list(nx.edge_boundary(P10, [1, 2, 3])) == [(3, 4)]
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assert (sorted(nx.edge_boundary(P10, [4, 5, 6])) ==
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[(4, 3), (6, 7)])
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assert (sorted(nx.edge_boundary(P10, [3, 4, 5, 6, 7])) ==
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[(3, 2), (7, 8)])
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assert list(nx.edge_boundary(P10, [8, 9, 10])) == [(8, 7)]
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assert sorted(nx.edge_boundary(P10, [4, 5, 6], [9, 10])) == []
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assert (list(nx.edge_boundary(P10, [1, 2, 3], [3, 4, 5])) ==
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[(2, 3), (3, 4)])
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def test_complete_graph(self):
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K10 = cnlti(nx.complete_graph(10), first_label=1)
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def ilen(iterable): return sum(1 for i in iterable)
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assert list(nx.edge_boundary(K10, [])) == []
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assert list(nx.edge_boundary(K10, [], [])) == []
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assert ilen(nx.edge_boundary(K10, [1, 2, 3])) == 21
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assert ilen(nx.edge_boundary(K10, [4, 5, 6, 7])) == 24
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assert ilen(nx.edge_boundary(K10, [3, 4, 5, 6, 7])) == 25
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assert ilen(nx.edge_boundary(K10, [8, 9, 10])) == 21
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assert_edges_equal(nx.edge_boundary(K10, [4, 5, 6], [9, 10]),
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[(4, 9), (4, 10), (5, 9), (5, 10), (6, 9), (6, 10)])
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assert_edges_equal(nx.edge_boundary(K10, [1, 2, 3], [3, 4, 5]),
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[(1, 3), (1, 4), (1, 5), (2, 3), (2, 4),
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(2, 5), (3, 4), (3, 5)])
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def test_directed(self):
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"""Tests the edge boundary of a directed graph."""
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G = nx.DiGraph([(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)])
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S = {0, 1}
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boundary = list(nx.edge_boundary(G, S))
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expected = [(1, 2)]
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assert boundary == expected
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def test_multigraph(self):
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"""Tests the edge boundary of a multigraph."""
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G = nx.MultiGraph(list(nx.cycle_graph(5).edges()) * 2)
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S = {0, 1}
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boundary = list(nx.edge_boundary(G, S))
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expected = [(0, 4), (0, 4), (1, 2), (1, 2)]
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assert boundary == expected
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def test_multidigraph(self):
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"""Tests the edge boundary of a multdiigraph."""
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edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)]
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G = nx.MultiDiGraph(edges * 2)
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S = {0, 1}
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boundary = list(nx.edge_boundary(G, S))
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expected = [(1, 2), (1, 2)]
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assert boundary == expected
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