1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
#!/usr/bin/env python
from nose.tools import *
import networkx as nx
from networkx import NetworkXNotImplemented
class TestStronglyConnected:
def setUp(self):
self.gc = []
G = nx.DiGraph()
G.add_edges_from([(1, 2), (2, 3), (2, 8), (3, 4), (3, 7), (4, 5),
(5, 3), (5, 6), (7, 4), (7, 6), (8, 1), (8, 7)])
C = {frozenset([3, 4, 5, 7]), frozenset([1, 2, 8]), frozenset([6])}
self.gc.append((G, C))
G = nx.DiGraph()
G.add_edges_from([(1, 2), (1, 3), (1, 4), (4, 2), (3, 4), (2, 3)])
C = {frozenset([2, 3, 4]), frozenset([1])}
self.gc.append((G, C))
G = nx.DiGraph()
G.add_edges_from([(1, 2), (2, 3), (3, 2), (2, 1)])
C = {frozenset([1, 2, 3])}
self.gc.append((G, C))
# Eppstein's tests
G = nx.DiGraph({0: [1], 1:[2, 3], 2:[4, 5], 3:[4, 5], 4:[6], 5:[], 6:[]})
C = {
frozenset([0]),
frozenset([1]),
frozenset([2]),
frozenset([3]),
frozenset([4]),
frozenset([5]),
frozenset([6]),
}
self.gc.append((G, C))
G = nx.DiGraph({0:[1], 1:[2, 3, 4], 2:[0, 3], 3:[4], 4:[3]})
C = {frozenset([0, 1, 2]), frozenset([3, 4])}
self.gc.append((G, C))
def test_tarjan(self):
scc = nx.strongly_connected_components
for G, C in self.gc:
assert_equal({frozenset(g) for g in scc(G)}, C)
def test_tarjan_recursive(self):
scc=nx.strongly_connected_components_recursive
for G, C in self.gc:
assert_equal({frozenset(g) for g in scc(G)}, C)
def test_kosaraju(self):
scc = nx.kosaraju_strongly_connected_components
for G, C in self.gc:
assert_equal({frozenset(g) for g in scc(G)}, C)
def test_number_strongly_connected_components(self):
ncc = nx.number_strongly_connected_components
for G, C in self.gc:
assert_equal(ncc(G), len(C))
def test_is_strongly_connected(self):
for G, C in self.gc:
if len(C) == 1:
assert_true(nx.is_strongly_connected(G))
else:
assert_false(nx.is_strongly_connected(G))
def test_strongly_connected_component_subgraphs(self):
scc = nx.strongly_connected_component_subgraphs
for G, C in self.gc:
assert_equal({frozenset(g) for g in scc(G)}, C)
def test_contract_scc1(self):
G = nx.DiGraph()
G.add_edges_from([
(1, 2), (2, 3), (2, 11), (2, 12), (3, 4), (4, 3), (4, 5), (5, 6),
(6, 5), (6, 7), (7, 8), (7, 9), (7, 10), (8, 9), (9, 7), (10, 6),
(11, 2), (11, 4), (11, 6), (12, 6), (12, 11),
])
scc = list(nx.strongly_connected_components(G))
cG = nx.condensation(G, scc)
# DAG
assert_true(nx.is_directed_acyclic_graph(cG))
# nodes
assert_equal(sorted(cG.nodes()), [0, 1, 2, 3])
# edges
mapping={}
for i, component in enumerate(scc):
for n in component:
mapping[n] = i
edge = (mapping[2], mapping[3])
assert_true(cG.has_edge(*edge))
edge = (mapping[2], mapping[5])
assert_true(cG.has_edge(*edge))
edge = (mapping[3], mapping[5])
assert_true(cG.has_edge(*edge))
def test_contract_scc_isolate(self):
# Bug found and fixed in [1687].
G = nx.DiGraph()
G.add_edge(1, 2)
G.add_edge(2, 1)
scc = list(nx.strongly_connected_components(G))
cG = nx.condensation(G, scc)
assert_equal(list(cG.nodes()), [0])
assert_equal(list(cG.edges()), [])
def test_contract_scc_edge(self):
G = nx.DiGraph()
G.add_edge(1, 2)
G.add_edge(2, 1)
G.add_edge(2, 3)
G.add_edge(3, 4)
G.add_edge(4, 3)
scc = list(nx.strongly_connected_components(G))
cG = nx.condensation(G, scc)
assert_equal(cG.nodes(), [0, 1])
if 1 in scc[0]:
edge = (0, 1)
else:
edge = (1, 0)
assert_equal(list(cG.edges()), [edge])
def test_condensation_mapping_and_members(self):
G, C = self.gc[1]
C = sorted(C, key=len, reverse=True)
cG = nx.condensation(G)
mapping = cG.graph['mapping']
assert_true(all(n in G for n in mapping))
assert_true(all(0 == cN for n, cN in mapping.items() if n in C[0]))
assert_true(all(1 == cN for n, cN in mapping.items() if n in C[1]))
for n, d in cG.nodes(data=True):
assert_equal(set(C[n]), cG.node[n]['members'])
def test_connected_raise(self):
G=nx.Graph()
assert_raises(NetworkXNotImplemented, nx.strongly_connected_components, G)
assert_raises(NetworkXNotImplemented, nx.kosaraju_strongly_connected_components, G)
assert_raises(NetworkXNotImplemented, nx.strongly_connected_components_recursive, G)
assert_raises(NetworkXNotImplemented, nx.strongly_connected_component_subgraphs, G)
assert_raises(NetworkXNotImplemented, nx.is_strongly_connected, G)
assert_raises(nx.NetworkXPointlessConcept, nx.is_strongly_connected, nx.DiGraph())
assert_raises(NetworkXNotImplemented, nx.condensation, G)
|
