def test_star(self):
graph = nx.star_graph(10)
F = TseitinFormula(graph)
self.assertEqual(len(list(F.variables())), 10)
self.assertEqual(len(F), 2**9 + 10)
self.assertEqual(len([C for C in F if len(C) == 10]), 2**9)
self.assertEqual(len([C for C in F if len(C) == 1]), 10)
for C in F:
if len(C) == 1:
self.assertFalse(C[0][0])
def test_star(self):
graph=nx.star_graph(10)
F = TseitinFormula(graph)
self.assertEquals(len(list(F.variables())),10)
self.assertEquals(len(list(F.clauses())),2**9+10)
self.assertEquals(len([C for C in F.clauses() if len(C)==10]),2**9)
self.assertEquals(len([C for C in F.clauses() if len(C)==1]),10)
for C in F.clauses():
if len(C)==1:
self.assertFalse(C[0][0])
def test_null(self):
dimacs = """\
p cnf 0 0
"""
graph = nx.null_graph()
F = TseitinFormula(graph)
self.assertCnfEqualsDimacs(F, dimacs)
def test_empty_graph(self):
dimacs = """\
p cnf 0 1
0
"""
graph = nx.empty_graph(10)
F = TseitinFormula(graph)
self.assertCnfEqualsDimacs(F, dimacs)
def test_one_edge(self):
dimacs = """\
p cnf 1 2
1 0
-1 0
"""
graph = nx.path_graph(2)
F = TseitinFormula(graph)
self.assertCnfEqualsDimacs(F, dimacs)
def test_multi_edge(self):
dimacs = """\
p cnf 2 4
1 -2 0
-1 2 0
1 2 0
-1 -2 0
"""
graph = nx.MultiGraph()
graph.add_nodes_from((0, 1))
graph.add_edges_from(((0, 1), (0, 1)))
F = TseitinFormula(graph)
self.assertCnfEqualsDimacs(F, dimacs)
def test_cycle(self):
for n in range(3, 8):
graph = nx.cycle_graph(n)
F = EvenColoringFormula(graph)
G = TseitinFormula(graph, [1] * n)
self.assertCnfEquivalentModuloVariables(F, G)
def test_charge_odd(self):
graph=nx.star_graph(10)
F = TseitinFormula(graph,[1]*11)
for C in F.clauses():
if len(C)==1:
self.assertTrue(C[0][0])
def test_parameters(self):
for sz in range(1, 5):
parameters = ["cnfgen", "-q", "tseitin", "--complete", sz]
graph = nx.complete_graph(sz)
F = TseitinFormula(graph)
self.checkFormula(sys.stdin, F, parameters)
def test_charge_first(self):
graph = nx.star_graph(10)
F = TseitinFormula(graph, [1])
G = TseitinFormula(graph)
self.assertCnfEqual(F, G)
def test_charge_odd(self):
graph = nx.star_graph(10)
F = TseitinFormula(graph, [1] * 11)
for C in F.clauses():
if len(C) == 1:
self.assertTrue(C[0][0])
def test_cycle(self):
for n in range(3, 8):
graph = nx.cycle_graph(n)
F = PerfectMatchingPrinciple(graph)
G = TseitinFormula(graph, [1] * n)
self.assertCnfEquivalentModuloVariables(F, G)
def test_charge_even(self):
graph = nx.star_graph(10)
F = TseitinFormula(graph, [0] * 11)
for C in F:
if len(C) == 1:
self.assertFalse(C[0][0])
