def test_simulated_annealing_threshold_restart(self):
"""
Tests that the simulated annealing heuristic restarts properly when using the threshold
method for finding the next relevant parameter.
"""
np.random.seed(10)
ranges = np.array([np.arange(20), np.arange(20)])
sa = SimulatedAnnealing(
initial_temperature=50,
neighbor_function=hop_to_next_value,
cooldown_function=multiplicative_schedule,
cooling_factor=3,
restart=threshold_restart,
probability_threshold=0.3,
)
next_parameter = sa.choose_next_parameter(fake_history, ranges)
expected_next_parameter = np.array([2, 6])
np.testing.assert_array_equal(next_parameter, expected_next_parameter)
def test_simulated_annealing_temp_stop(self):
"""
Tests that the simulated annealing heuristic stop properly when reaching a low temperature.
"""
np.random.seed(10)
ranges = np.array([np.arange(20), np.arange(20)])
sa = SimulatedAnnealing(
initial_temperature=0.1,
neighbor_function=hop_to_next_value,
cooldown_function=multiplicative_schedule,
cooling_factor=10,
restart=threshold_restart,
probability_threshold=0.3,
)
sa.choose_next_parameter(fake_history, ranges) # first computation
next_parameter = sa.choose_next_parameter(fake_history, ranges)
expected_next_parameter = np.array([4, 3])
np.testing.assert_array_equal(next_parameter, expected_next_parameter)
self.assertTrue(sa.stop)
def test_reset(self):
"""
Tests that the "reset" method reset the attributes.
"""
np.random.seed(10)
ranges = np.array([np.arange(20), np.arange(20)])
sa = SimulatedAnnealing(
initial_temperature=50,
neighbor_function=hop_to_next_value,
cooldown_function=multiplicative_schedule,
cooling_factor=3,
restart=threshold_restart,
probability_threshold=0.3,
)
next_parameter = sa.choose_next_parameter(fake_history, ranges)
expected_next_parameter = np.array([2, 6])
np.testing.assert_array_equal(next_parameter, expected_next_parameter)
sa.reset()
self.assertEqual(sa.current_t, 50)
self.assertEqual(sa.nbr_iteration, 0)
self.assertEqual(sa.restart, 0)
self.assertListEqual(sa.energy, list())
def test_simulated_annealing_neg_temp(self):
"""
Tests that the simulated annealing raises an error when given a negative initial
temperature.
"""
with self.assertRaises(TypeError):
SimulatedAnnealing(
initial_temperature=-1,
neighbor_function=hop_to_next_value,
cooldown_function=multiplicative_schedule,
cooling_factor=2,
restart=False,
)
def test_simulated_annealing_wrong_temp(self):
"""
Tests that the simulated annealing class raises an error when the temperature is of the
wrong type.
"""
with self.assertRaises(TypeError):
SimulatedAnnealing(
initial_temperature="tutu",
neighbor_function=hop_to_next_value,
cooldown_function=multiplicative_schedule,
cooling_factor=2,
restart=False,
)