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mightyscape-1.1-deprecated/extensions/networkx/algorithms/bipartite/tests/test_spectral_bipartivity.py
2020-07-30 01:16:18 +02:00

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2.4 KiB
Python

# -*- coding: utf-8 -*-
import pytest
import networkx as nx
from networkx.algorithms.bipartite import spectral_bipartivity as sb
from networkx.testing import almost_equal
# Examples from Figure 1
# E. Estrada and J. A. Rodríguez-Velázquez, "Spectral measures of
# bipartivity in complex networks", PhysRev E 72, 046105 (2005)
class TestSpectralBipartivity(object):
@classmethod
def setup_class(cls):
global scipy
scipy = pytest.importorskip('scipy')
def test_star_like(self):
# star-like
G = nx.star_graph(2)
G.add_edge(1, 2)
assert almost_equal(sb(G), 0.843, places=3)
G = nx.star_graph(3)
G.add_edge(1, 2)
assert almost_equal(sb(G), 0.871, places=3)
G = nx.star_graph(4)
G.add_edge(1, 2)
assert almost_equal(sb(G), 0.890, places=3)
def k23_like(self):
# K2,3-like
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(0, 1)
assert almost_equal(sb(G), 0.769, places=3)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(2, 4)
assert almost_equal(sb(G), 0.829, places=3)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(2, 4)
G.add_edge(3, 4)
assert almost_equal(sb(G), 0.731, places=3)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(0, 1)
G.add_edge(2, 4)
assert almost_equal(sb(G), 0.692, places=3)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(2, 4)
G.add_edge(3, 4)
G.add_edge(0, 1)
assert almost_equal(sb(G), 0.645, places=3)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(2, 4)
G.add_edge(3, 4)
G.add_edge(2, 3)
assert almost_equal(sb(G), 0.645, places=3)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(2, 4)
G.add_edge(3, 4)
G.add_edge(2, 3)
G.add_edge(0, 1)
assert almost_equal(sb(G), 0.597, places=3)
def test_single_nodes(self):
# single nodes
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(2, 4)
sbn = sb(G, nodes=[1, 2])
assert almost_equal(sbn[1], 0.85, places=2)
assert almost_equal(sbn[2], 0.77, places=2)
G = nx.complete_bipartite_graph(2, 3)
G.add_edge(0, 1)
sbn = sb(G, nodes=[1, 2])
assert almost_equal(sbn[1], 0.73, places=2)
assert almost_equal(sbn[2], 0.82, places=2)