def cut_and_solve_basic(kpp):
max_cliques = kpp.G.maximal_cliques()
k = kpp.k
kpp.add_separator(YCliqueSeparator(max_cliques, 4, k))
kpp.add_separator(YCliqueSeparator(max_cliques, 5, k))
kpp.cut()
kpp.solve()
def cut_and_solve_extension(kpp):
max_cliques = kpp.G.maximal_cliques()
k = kpp.k
k2 = kpp.k2
kpp.add_separator(YCliqueSeparator(max_cliques, 4, k))
kpp.add_separator(YCliqueSeparator(max_cliques, 5, k))
kpp.cut()
kpp.sep_algs.clear()
kpp.add_z_variables()
kpp.add_separator(YZCliqueSeparator(max_cliques, 7, k, k2))
kpp.add_separator(ZCliqueSeparator(max_cliques, 8, k, k2))
kpp.cut()
kpp.solve()
def test_cuts(self):
print("\ttest_cuts...")
cuts_kpp = KPP(self.G, k, verbosity=0)
cuts_kpp.add_separator(YCliqueSeparator(self.max_cliques, k + 1, k))
cuts_kpp.cut()
cuts_kpp.solve()
obj_val = cuts_kpp.model.objVal
self.assertAlmostEqual(self.obj_val, obj_val)
def test_cuts_and_break_symmetry(self):
print("\ttest_cuts_and_break_symmetry...")
kpp = KPP(self.G, k, verbosity=0)
kpp.add_separator(YCliqueSeparator(self.max_cliques, k + 1, k))
kpp.cut()
kpp.break_symmetry()
kpp.solve()
obj_val = kpp.model.objVal
self.assertAlmostEqual(self.obj_val, obj_val)
def test_fractional_ycut(self):
print("\ttest_fractional_ycut...")
cuts_kpp = KPPExtension(self.G, k, k2, verbosity=0)
cuts_kpp.add_separator(YCliqueSeparator(self.max_cliques, k + 1, k))
y_sep_alg_1 = YCliqueSeparator(self.max_cliques, k + 1, k)
yz_sep_alg = YZCliqueSeparator(self.max_cliques, k2 * k + 1, k, k2)
z_sep_alg = ZCliqueSeparator(self.max_cliques, k2 * k + 2, k, k2)
cuts_kpp.add_separator(y_sep_alg_1)
cuts_kpp.cut()
cuts_kpp.add_fractional_cut()
cuts_kpp.sep_algs = []
cuts_kpp.add_z_variables()
cuts_kpp.add_separator(yz_sep_alg)
cuts_kpp.add_separator(z_sep_alg)
cuts_kpp.cut()
cuts_kpp.solve()
obj_val = cuts_kpp.model.objVal
self.assertAlmostEqual(self.obj_val, obj_val)
def test_cuts_and_break_symmetry(self):
print("\ttest_cuts_and_break_symmetry...")
kpp = KPPExtension(self.G, k, k2, verbosity=0)
y_sep_alg_1 = YCliqueSeparator(self.max_cliques, k + 1, k)
y_sep_alg_2 = YCliqueSeparator(self.max_cliques, k + 2, k)
yz_sep_alg = YZCliqueSeparator(self.max_cliques, k * k2 + 1, k, k2)
z_sep_alg = ZCliqueSeparator(self.max_cliques, k * k2 + 2, k, k2)
kpp.add_separator(y_sep_alg_1)
kpp.add_separator(y_sep_alg_2)
kpp.cut()
kpp.sep_algs = []
kpp.add_z_variables()
kpp.add_separator(yz_sep_alg)
kpp.add_separator(z_sep_alg)
kpp.cut()
kpp.break_symmetry()
kpp.solve()
obj_val = kpp.model.objVal
self.assertAlmostEqual(self.obj_val, obj_val)
def test_YCliqueSeparator(n, k):
graph = ig.Graph.Full(n)
for e in graph.es():
e["weight"] = random()
kpp = KPP(graph, k, verbosity=0)
kpp.solve()
opt_val = kpp.model.objVal
max_cliques = graph.maximal_cliques() # [graph.vs()]
kpp_sep = KPP(graph, k, verbosity=0)
for p in range(k + 1, n + 1):
kpp_sep.add_separator(YCliqueSeparator(max_cliques, p, k))
kpp_sep.cut()
kpp_sep.add_node_variables()
kpp_sep.solve()
new_opt_val = kpp_sep.model.objVal
assert isclose(opt_val, new_opt_val)