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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
import pytest
import networkx as nx
class TestConfigurationModel:
"""Unit tests for the :func:`~networkx.configuration_model`
function.
"""
def test_empty_degree_sequence(self):
"""Tests that an empty degree sequence yields the null graph."""
G = nx.configuration_model([])
assert len(G) == 0
def test_degree_zero(self):
"""Tests that a degree sequence of all zeros yields the empty
graph.
"""
G = nx.configuration_model([0, 0, 0])
assert len(G) == 3
assert G.number_of_edges() == 0
def test_degree_sequence(self):
"""Tests that the degree sequence of the generated graph matches
the input degree sequence.
"""
deg_seq = [5, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
G = nx.configuration_model(deg_seq, seed=12345678)
assert sorted((d for n, d in G.degree()), reverse=True) == [
5,
3,
3,
3,
3,
2,
2,
2,
1,
1,
1,
]
assert sorted((d for n, d in G.degree(range(len(deg_seq)))), reverse=True) == [
5,
3,
3,
3,
3,
2,
2,
2,
1,
1,
1,
]
def test_random_seed(self):
"""Tests that each call with the same random seed generates the
same graph.
"""
deg_seq = [3] * 12
G1 = nx.configuration_model(deg_seq, seed=1000)
G2 = nx.configuration_model(deg_seq, seed=1000)
assert nx.is_isomorphic(G1, G2)
G1 = nx.configuration_model(deg_seq, seed=10)
G2 = nx.configuration_model(deg_seq, seed=10)
assert nx.is_isomorphic(G1, G2)
def test_directed_disallowed(self):
"""Tests that attempting to create a configuration model graph
using a directed graph yields an exception.
"""
with pytest.raises(nx.NetworkXNotImplemented):
nx.configuration_model([], create_using=nx.DiGraph())
def test_odd_degree_sum(self):
"""Tests that a degree sequence whose sum is odd yields an
exception.
"""
with pytest.raises(nx.NetworkXError):
nx.configuration_model([1, 2])
def test_directed_configuration_raise_unequal():
with pytest.raises(nx.NetworkXError):
zin = [5, 3, 3, 3, 3, 2, 2, 2, 1, 1]
zout = [5, 3, 3, 3, 3, 2, 2, 2, 1, 2]
nx.directed_configuration_model(zin, zout)
def test_directed_configuration_model():
G = nx.directed_configuration_model([], [], seed=0)
assert len(G) == 0
def test_simple_directed_configuration_model():
G = nx.directed_configuration_model([1, 1], [1, 1], seed=0)
assert len(G) == 2
def test_expected_degree_graph_empty():
# empty graph has empty degree sequence
deg_seq = []
G = nx.expected_degree_graph(deg_seq)
assert dict(G.degree()) == {}
def test_expected_degree_graph():
# test that fixed seed delivers the same graph
deg_seq = [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3]
G1 = nx.expected_degree_graph(deg_seq, seed=1000)
assert len(G1) == 12
G2 = nx.expected_degree_graph(deg_seq, seed=1000)
assert nx.is_isomorphic(G1, G2)
G1 = nx.expected_degree_graph(deg_seq, seed=10)
G2 = nx.expected_degree_graph(deg_seq, seed=10)
assert nx.is_isomorphic(G1, G2)
def test_expected_degree_graph_selfloops():
deg_seq = [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3]
G1 = nx.expected_degree_graph(deg_seq, seed=1000, selfloops=False)
G2 = nx.expected_degree_graph(deg_seq, seed=1000, selfloops=False)
assert nx.is_isomorphic(G1, G2)
assert len(G1) == 12
def test_expected_degree_graph_skew():
deg_seq = [10, 2, 2, 2, 2]
G1 = nx.expected_degree_graph(deg_seq, seed=1000)
G2 = nx.expected_degree_graph(deg_seq, seed=1000)
assert nx.is_isomorphic(G1, G2)
assert len(G1) == 5
def test_havel_hakimi_construction():
G = nx.havel_hakimi_graph([])
assert len(G) == 0
z = [1000, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z)
z = ["A", 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z)
z = [5, 4, 3, 3, 3, 2, 2, 2]
G = nx.havel_hakimi_graph(z)
G = nx.configuration_model(z)
z = [6, 5, 4, 4, 2, 1, 1, 1]
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z)
z = [10, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2]
G = nx.havel_hakimi_graph(z)
pytest.raises(nx.NetworkXError, nx.havel_hakimi_graph, z, create_using=nx.DiGraph())
def test_directed_havel_hakimi():
# Test range of valid directed degree sequences
n, r = 100, 10
p = 1.0 / r
for i in range(r):
G1 = nx.erdos_renyi_graph(n, p * (i + 1), None, True)
din1 = [d for n, d in G1.in_degree()]
dout1 = [d for n, d in G1.out_degree()]
G2 = nx.directed_havel_hakimi_graph(din1, dout1)
din2 = [d for n, d in G2.in_degree()]
dout2 = [d for n, d in G2.out_degree()]
assert sorted(din1) == sorted(din2)
assert sorted(dout1) == sorted(dout2)
# Test non-graphical sequence
dout = [1000, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1]
din = [103, 102, 102, 102, 102, 102, 102, 102, 102, 102]
pytest.raises(nx.exception.NetworkXError, nx.directed_havel_hakimi_graph, din, dout)
# Test valid sequences
dout = [1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
din = [2, 2, 2, 2, 2, 2, 2, 2, 0, 2]
G2 = nx.directed_havel_hakimi_graph(din, dout)
dout2 = (d for n, d in G2.out_degree())
din2 = (d for n, d in G2.in_degree())
assert sorted(dout) == sorted(dout2)
assert sorted(din) == sorted(din2)
# Test unequal sums
din = [2, 2, 2, 2, 2, 2, 2, 2, 2, 2]
pytest.raises(nx.exception.NetworkXError, nx.directed_havel_hakimi_graph, din, dout)
# Test for negative values
din = [2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -2]
pytest.raises(nx.exception.NetworkXError, nx.directed_havel_hakimi_graph, din, dout)
def test_degree_sequence_tree():
z = [1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
G = nx.degree_sequence_tree(z)
assert len(G) == len(z)
assert len(list(G.edges())) == sum(z) / 2
pytest.raises(
nx.NetworkXError, nx.degree_sequence_tree, z, create_using=nx.DiGraph()
)
z = [1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
pytest.raises(nx.NetworkXError, nx.degree_sequence_tree, z)
def test_random_degree_sequence_graph():
d = [1, 2, 2, 3]
G = nx.random_degree_sequence_graph(d, seed=42)
assert d == sorted(d for n, d in G.degree())
def test_random_degree_sequence_graph_raise():
z = [1, 1, 1, 1, 1, 1, 2, 2, 2, 3, 4]
pytest.raises(nx.NetworkXUnfeasible, nx.random_degree_sequence_graph, z)
def test_random_degree_sequence_large():
G1 = nx.fast_gnp_random_graph(100, 0.1, seed=42)
d1 = (d for n, d in G1.degree())
G2 = nx.random_degree_sequence_graph(d1, seed=42)
d2 = (d for n, d in G2.degree())
assert sorted(d1) == sorted(d2)
|
