### comparison env/lib/python3.9/site-packages/networkx/algorithms/tests/test_boundary.py @ 0:4f3585e2f14bdraftdefaulttip

author shellac Mon, 22 Mar 2021 18:12:50 +0000
comparison
equal inserted replaced
-1:000000000000 0:4f3585e2f14b
1 """Unit tests for the :mod:`networkx.algorithms.boundary` module."""
2
3 from itertools import combinations
4
5 import networkx as nx
6 from networkx.testing import almost_equal, assert_edges_equal
7 from networkx import convert_node_labels_to_integers as cnlti
8
9
10 class TestNodeBoundary:
11 """Unit tests for the :func:`~networkx.node_boundary` function."""
12
13 def test_null_graph(self):
14 """Tests that the null graph has empty node boundaries."""
15 null = nx.null_graph()
16 assert nx.node_boundary(null, []) == set()
17 assert nx.node_boundary(null, [], []) == set()
18 assert nx.node_boundary(null, [1, 2, 3]) == set()
19 assert nx.node_boundary(null, [1, 2, 3], [4, 5, 6]) == set()
20 assert nx.node_boundary(null, [1, 2, 3], [3, 4, 5]) == set()
21
22 def test_path_graph(self):
23 P10 = cnlti(nx.path_graph(10), first_label=1)
24 assert nx.node_boundary(P10, []) == set()
25 assert nx.node_boundary(P10, [], []) == set()
26 assert nx.node_boundary(P10, [1, 2, 3]) == {4}
27 assert nx.node_boundary(P10, [4, 5, 6]) == {3, 7}
28 assert nx.node_boundary(P10, [3, 4, 5, 6, 7]) == {2, 8}
29 assert nx.node_boundary(P10, [8, 9, 10]) == {7}
30 assert nx.node_boundary(P10, [4, 5, 6], [9, 10]) == set()
31
32 def test_complete_graph(self):
33 K10 = cnlti(nx.complete_graph(10), first_label=1)
34 assert nx.node_boundary(K10, []) == set()
35 assert nx.node_boundary(K10, [], []) == set()
36 assert nx.node_boundary(K10, [1, 2, 3]) == {4, 5, 6, 7, 8, 9, 10}
37 assert nx.node_boundary(K10, [4, 5, 6]) == {1, 2, 3, 7, 8, 9, 10}
38 assert nx.node_boundary(K10, [3, 4, 5, 6, 7]) == {1, 2, 8, 9, 10}
39 assert nx.node_boundary(K10, [4, 5, 6], []) == set()
40 assert nx.node_boundary(K10, K10) == set()
41 assert nx.node_boundary(K10, [1, 2, 3], [3, 4, 5]) == {4, 5}
42
43 def test_petersen(self):
44 """Check boundaries in the petersen graph
45
46 cheeger(G,k)=min(|bdy(S)|/|S| for |S|=k, 0<k<=|V(G)|/2)
47
48 """
49
50 def cheeger(G, k):
51 return min(len(nx.node_boundary(G, nn)) / k for nn in combinations(G, k))
52
53 P = nx.petersen_graph()
54 assert almost_equal(cheeger(P, 1), 3.00, places=2)
55 assert almost_equal(cheeger(P, 2), 2.00, places=2)
56 assert almost_equal(cheeger(P, 3), 1.67, places=2)
57 assert almost_equal(cheeger(P, 4), 1.00, places=2)
58 assert almost_equal(cheeger(P, 5), 0.80, places=2)
59
60 def test_directed(self):
61 """Tests the node boundary of a directed graph."""
62 G = nx.DiGraph([(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)])
63 S = {0, 1}
64 boundary = nx.node_boundary(G, S)
65 expected = {2}
66 assert boundary == expected
67
68 def test_multigraph(self):
69 """Tests the node boundary of a multigraph."""
70 G = nx.MultiGraph(list(nx.cycle_graph(5).edges()) * 2)
71 S = {0, 1}
72 boundary = nx.node_boundary(G, S)
73 expected = {2, 4}
74 assert boundary == expected
75
76 def test_multidigraph(self):
77 """Tests the edge boundary of a multdiigraph."""
78 edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)]
79 G = nx.MultiDiGraph(edges * 2)
80 S = {0, 1}
81 boundary = nx.node_boundary(G, S)
82 expected = {2}
83 assert boundary == expected
84
85
86 class TestEdgeBoundary:
87 """Unit tests for the :func:`~networkx.edge_boundary` function."""
88
89 def test_null_graph(self):
90 null = nx.null_graph()
91 assert list(nx.edge_boundary(null, [])) == []
92 assert list(nx.edge_boundary(null, [], [])) == []
93 assert list(nx.edge_boundary(null, [1, 2, 3])) == []
94 assert list(nx.edge_boundary(null, [1, 2, 3], [4, 5, 6])) == []
95 assert list(nx.edge_boundary(null, [1, 2, 3], [3, 4, 5])) == []
96
97 def test_path_graph(self):
98 P10 = cnlti(nx.path_graph(10), first_label=1)
99 assert list(nx.edge_boundary(P10, [])) == []
100 assert list(nx.edge_boundary(P10, [], [])) == []
101 assert list(nx.edge_boundary(P10, [1, 2, 3])) == [(3, 4)]
102 assert sorted(nx.edge_boundary(P10, [4, 5, 6])) == [(4, 3), (6, 7)]
103 assert sorted(nx.edge_boundary(P10, [3, 4, 5, 6, 7])) == [(3, 2), (7, 8)]
104 assert list(nx.edge_boundary(P10, [8, 9, 10])) == [(8, 7)]
105 assert sorted(nx.edge_boundary(P10, [4, 5, 6], [9, 10])) == []
106 assert list(nx.edge_boundary(P10, [1, 2, 3], [3, 4, 5])) == [(2, 3), (3, 4)]
107
108 def test_complete_graph(self):
109 K10 = cnlti(nx.complete_graph(10), first_label=1)
110
111 def ilen(iterable):
112 return sum(1 for i in iterable)
113
114 assert list(nx.edge_boundary(K10, [])) == []
115 assert list(nx.edge_boundary(K10, [], [])) == []
116 assert ilen(nx.edge_boundary(K10, [1, 2, 3])) == 21
117 assert ilen(nx.edge_boundary(K10, [4, 5, 6, 7])) == 24
118 assert ilen(nx.edge_boundary(K10, [3, 4, 5, 6, 7])) == 25
119 assert ilen(nx.edge_boundary(K10, [8, 9, 10])) == 21
120 assert_edges_equal(
121 nx.edge_boundary(K10, [4, 5, 6], [9, 10]),
122 [(4, 9), (4, 10), (5, 9), (5, 10), (6, 9), (6, 10)],
123 )
124 assert_edges_equal(
125 nx.edge_boundary(K10, [1, 2, 3], [3, 4, 5]),
126 [(1, 3), (1, 4), (1, 5), (2, 3), (2, 4), (2, 5), (3, 4), (3, 5)],
127 )
128
129 def test_directed(self):
130 """Tests the edge boundary of a directed graph."""
131 G = nx.DiGraph([(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)])
132 S = {0, 1}
133 boundary = list(nx.edge_boundary(G, S))
134 expected = [(1, 2)]
135 assert boundary == expected
136
137 def test_multigraph(self):
138 """Tests the edge boundary of a multigraph."""
139 G = nx.MultiGraph(list(nx.cycle_graph(5).edges()) * 2)
140 S = {0, 1}
141 boundary = list(nx.edge_boundary(G, S))
142 expected = [(0, 4), (0, 4), (1, 2), (1, 2)]
143 assert boundary == expected
144
145 def test_multidigraph(self):
146 """Tests the edge boundary of a multdiigraph."""
147 edges = [(0, 1), (1, 2), (2, 3), (3, 4), (4, 0)]
148 G = nx.MultiDiGraph(edges * 2)
149 S = {0, 1}
150 boundary = list(nx.edge_boundary(G, S))
151 expected = [(1, 2), (1, 2)]
152 assert boundary == expected