def test_stochastic_descent_maximize(self):
# Every 2-SAT with just one clause will not be satisfied by 1/4 of all
# possible literal assignments.
# With only one bang, the only way to do better than random guessing is to
# apply the DNF hamiltonian.
dnf = dnf_lib.DNF(2, [dnf_lib.Clause(0, 1, True, True)])
circuit = dnf_circuit_lib.BangBangProtocolCircuit(1, dnf)
random_protocol = stochastic_descent_lib.get_random_protocol(2)
random_eval = circuit.get_constraint_expectation(
circuit.get_wavefunction(random_protocol))
protocol, evaluation, num_epoch = stochastic_descent_lib.stochastic_descent(
circuit=circuit,
max_num_flips=2,
initial_protocol=stochastic_descent_lib.get_random_protocol(5),
minimize=False)
self.assertLen(protocol, 5)
self.assertIsInstance(evaluation, float)
self.assertGreaterEqual(evaluation, random_eval)
# Contain at least 1 epoch of stochastic descent.
self.assertGreaterEqual(num_epoch, 1)
def test_stochastic_descent_neg_max_num_flips(self):
# Every 2-SAT with just one clause will not be satisfied by 1/4 of all
# possible literal assignments.
# With only one bang, the only way to do better than random guessing is to
# apply the DNF hamiltonian.
dnf = dnf_lib.DNF(3, [dnf_lib.Clause(0, 1, False, True)])
circuit = dnf_circuit_lib.BangBangProtocolCircuit(1, dnf)
with self.assertRaisesRegex(
ValueError, 'max_num_flips should be positive, not -10'):
stochastic_descent_lib.stochastic_descent(
circuit=circuit,
max_num_flips=-10,
initial_protocol=stochastic_descent_lib.get_random_protocol(5),
minimize=False)
def test_stochastic_descent_skip_search(self):
dnf = dnf_lib.DNF(2, [dnf_lib.Clause(0, 1, True, True)])
circuit = dnf_circuit_lib.BangBangProtocolCircuit(1, dnf)
random_protocol = stochastic_descent_lib.get_random_protocol(2)
random_eval = circuit.get_constraint_expectation(
circuit.get_wavefunction(random_protocol))
protocol, evaluation, num_epoch = stochastic_descent_lib.stochastic_descent(
circuit=circuit,
max_num_flips=1,
initial_protocol=random_protocol,
minimize=False,
skip_search=True)
self.assertListEqual(protocol, random_protocol)
self.assertIsInstance(evaluation, float)
self.assertAlmostEqual(evaluation, random_eval)
# Zero epoch of stochastic descent.
self.assertEqual(num_epoch, 0)
def test_get_random_protocol_neg_chunks(self):
with self.assertRaisesRegex(ValueError,
'num_chunks should be positive, not -4'):
stochastic_descent_lib.get_random_protocol(-4)
def test_get_random_protocol(self, seed, expected_protocol):
self.assertListEqual(
stochastic_descent_lib.get_random_protocol(
num_chunks=5, random_state=np.random.RandomState(seed)),
expected_protocol)
