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import random
import unittest
from igraph import Graph
class CycleTests(unittest.TestCase):
def setUp(self):
random.seed(42)
def test_is_acyclic(self):
g = Graph.Tree(121, 3, mode="out")
self.assertTrue(g.is_acyclic())
g = Graph()
self.assertTrue(g.is_acyclic())
g = Graph.Ring(5)
self.assertFalse(g.is_acyclic())
def test_is_dag(self):
g = Graph(5, [(0, 1), (0, 2), (1, 2), (1, 3), (2, 3)], directed=True)
self.assertTrue(g.is_dag())
g.to_undirected()
self.assertFalse(g.is_dag())
g = Graph.Barabasi(1000, 2, directed=True)
self.assertTrue(g.is_dag())
g = Graph.GRG(100, 0.2)
self.assertFalse(g.is_dag())
g = Graph.Ring(10, directed=True, mutual=False)
self.assertFalse(g.is_dag())
def test_fundamental_cycles(self):
g = Graph(
[
(1, 2),
(2, 3),
(3, 1),
(4, 5),
(5, 4),
(4, 5),
(6, 7),
(7, 8),
(8, 9),
(9, 6),
(6, 8),
(10, 10),
(10, 11),
(12, 12),
]
)
cycles = [sorted(cycle) for cycle in g.fundamental_cycles()]
assert cycles == [[0, 1, 2], [4, 5], [3, 5], [6, 7, 10], [8, 9, 10], [11], [13]]
cycles = [sorted(cycle) for cycle in g.fundamental_cycles(start_vid=6)]
assert cycles == [[6, 7, 10], [8, 9, 10]]
cycles = [
sorted(cycle) for cycle in g.fundamental_cycles(start_vid=6, cutoff=1)
]
assert cycles == [[6, 7, 10], [8, 9, 10]]
def test_minimum_cycle_basis(self):
g = Graph(
[
(1, 2),
(2, 3),
(3, 1),
(4, 5),
(5, 4),
(4, 5),
(6, 7),
(7, 8),
(8, 9),
(9, 6),
(6, 8),
(10, 10),
(10, 11),
(12, 12),
]
)
cycles = g.minimum_cycle_basis()
assert cycles == [
(11,),
(13,),
(3, 5),
(4, 5),
(0, 1, 2),
(6, 7, 10),
(8, 9, 10),
]
g = Graph.Lattice((5, 6), circular=True)
cycles = g.minimum_cycle_basis()
expected = [
(0, 1, 10, 3),
(0, 51, 50, 53),
(1, 8, 9, 18),
(2, 3, 12, 5),
(2, 53, 52, 55),
(4, 5, 14, 7),
(4, 55, 54, 57),
(6, 7, 16, 9),
(6, 57, 56, 59),
(8, 59, 58, 51),
(10, 11, 20, 13),
(11, 18, 19, 28),
(12, 13, 22, 15),
(14, 15, 24, 17),
(16, 17, 26, 19),
(20, 21, 30, 23),
(21, 28, 29, 38),
(22, 23, 32, 25),
(24, 25, 34, 27),
(26, 27, 36, 29),
(30, 31, 40, 33),
(31, 38, 39, 48),
(32, 33, 42, 35),
(34, 35, 44, 37),
(36, 37, 46, 39),
(40, 41, 50, 43),
(41, 48, 49, 58),
(42, 43, 52, 45),
(44, 45, 54, 47),
(0, 8, 6, 4, 2),
(1, 51, 41, 31, 21, 11),
]
assert len(cycles) == len(expected)
for expected_cycle, observed_cycle in zip(expected, cycles):
assert expected_cycle == observed_cycle or expected_cycle == (
observed_cycle[0],
) + tuple(reversed(observed_cycle[1:]))
g = Graph.Lattice((5, 6), circular=True)
cycles = g.minimum_cycle_basis(cutoff=2, complete=False)
expected = [
(0, 1, 10, 3),
(0, 51, 50, 53),
(1, 8, 9, 18),
(2, 3, 12, 5),
(2, 53, 52, 55),
(4, 5, 14, 7),
(4, 55, 54, 57),
(6, 7, 16, 9),
(6, 57, 56, 59),
(8, 59, 58, 51),
(10, 11, 20, 13),
(11, 18, 19, 28),
(12, 13, 22, 15),
(14, 15, 24, 17),
(16, 17, 26, 19),
(20, 21, 30, 23),
(21, 28, 29, 38),
(22, 23, 32, 25),
(24, 25, 34, 27),
(26, 27, 36, 29),
(30, 31, 40, 33),
(31, 38, 39, 48),
(32, 33, 42, 35),
(34, 35, 44, 37),
(36, 37, 46, 39),
(40, 41, 50, 43),
(41, 48, 49, 58),
(42, 43, 52, 45),
(44, 45, 54, 47),
(0, 8, 6, 4, 2),
(1, 51, 41, 31, 21, 11),
]
assert len(cycles) == len(expected) - 1
for expected_cycle, observed_cycle in zip(expected[:-1], cycles):
assert expected_cycle == observed_cycle or expected_cycle == (
observed_cycle[0],
) + tuple(reversed(observed_cycle[1:]))
def suite():
cycle_suite = unittest.defaultTestLoader.loadTestsFromTestCase(CycleTests)
return unittest.TestSuite([cycle_suite])
def test():
runner = unittest.TextTestRunner()
runner.run(suite())
if __name__ == "__main__":
test()
|
