def test_aux_operator_std_dev_pauli(self):
"""Test non-zero standard deviations of aux operators with PauliExpectation."""
wavefunction = self.ry_wavefunction
vqd = VQD(
ansatz=wavefunction,
expectation=PauliExpectation(),
initial_point=[
1.70256666,
-5.34843975,
-0.39542903,
5.99477786,
-2.74374986,
-4.85284669,
0.2442925,
-1.51638917,
],
optimizer=COBYLA(maxiter=0),
quantum_instance=self.qasm_simulator,
)
# Go again with two auxiliary operators
aux_op1 = PauliSumOp.from_list([("II", 2.0)])
aux_op2 = PauliSumOp.from_list([("II", 0.5), ("ZZ", 0.5), ("YY", 0.5),
("XX", -0.5)])
aux_ops = [aux_op1, aux_op2]
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=aux_ops)
self.assertEqual(len(result.aux_operator_eigenvalues), 2)
# expectation values
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][0],
2.0,
places=1)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][0],
0.0019531249999999445,
places=1)
# standard deviations
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1],
0.015183867579396111,
places=1)
# Go again with additional None and zero operators
aux_ops = [*aux_ops, None, 0]
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=aux_ops)
self.assertEqual(len(result.aux_operator_eigenvalues[0]), 4)
# expectation values
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][0],
2.0,
places=1)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][0],
0.0019531249999999445,
places=1)
self.assertEqual(result.aux_operator_eigenvalues[0][2][0], 0.0)
self.assertEqual(result.aux_operator_eigenvalues[0][3][0], 0.0)
# # standard deviations
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1],
0.01548658094658011,
places=1)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][2][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][3][1], 0.0)
def test_reuse(self):
"""Test re-using a VQD algorithm instance."""
vqd = VQD(k=1)
with self.subTest(msg="assert running empty raises AlgorithmError"):
with self.assertRaises(AlgorithmError):
_ = vqd.compute_eigenvalues(operator=self.h2_op)
ansatz = TwoLocal(rotation_blocks=["ry", "rz"],
entanglement_blocks="cz")
vqd.ansatz = ansatz
with self.subTest(msg="assert missing operator raises AlgorithmError"):
with self.assertRaises(AlgorithmError):
_ = vqd.compute_eigenvalues(operator=self.h2_op)
vqd.expectation = MatrixExpectation()
vqd.quantum_instance = self.statevector_simulator
with self.subTest(msg="assert VQE works once all info is available"):
result = vqd.compute_eigenvalues(operator=self.h2_op)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy,
decimal=2)
operator = PrimitiveOp(
np.array([[1, 0, 0, 0], [0, -1, 0, 0], [0, 0, 2, 0], [0, 0, 0,
3]]))
with self.subTest(msg="assert minimum eigensolver interface works"):
result = vqd.compute_eigenvalues(operator=operator)
self.assertAlmostEqual(result.eigenvalues.real[0], -1.0, places=5)
def test_backend_change(self, user_expectation):
"""Test that VQE works when backend changes."""
vqd = VQD(
k=1,
ansatz=TwoLocal(rotation_blocks=["ry", "rz"],
entanglement_blocks="cz"),
optimizer=SLSQP(maxiter=2),
expectation=user_expectation,
quantum_instance=BasicAer.get_backend("statevector_simulator"),
)
result0 = vqd.compute_eigenvalues(operator=self.h2_op)
if user_expectation is not None:
with self.subTest("User expectation kept."):
self.assertEqual(vqd.expectation, user_expectation)
vqd.quantum_instance = BasicAer.get_backend("qasm_simulator")
# works also if no expectation is set, since it will be determined automatically
result1 = vqd.compute_eigenvalues(operator=self.h2_op)
if user_expectation is not None:
with self.subTest(
"Change backend with user expectation, it is kept."):
self.assertEqual(vqd.expectation, user_expectation)
with self.subTest("Check results."):
self.assertEqual(len(result0.optimal_point),
len(result1.optimal_point))
def test_callback(self):
"""Test the callback on VQD."""
history = {"eval_count": [], "parameters": [], "mean": [], "std": []}
def store_intermediate_result(eval_count, parameters, mean, std):
history["eval_count"].append(eval_count)
history["parameters"].append(parameters)
history["mean"].append(mean)
history["std"].append(std)
optimizer = COBYLA(maxiter=3)
wavefunction = self.ry_wavefunction
vqd = VQD(
ansatz=wavefunction,
optimizer=optimizer,
callback=store_intermediate_result,
quantum_instance=self.qasm_simulator,
)
vqd.compute_eigenvalues(operator=self.h2_op)
self.assertTrue(
all(isinstance(count, int) for count in history["eval_count"]))
self.assertTrue(
all(isinstance(mean, float) for mean in history["mean"]))
self.assertTrue(all(isinstance(std, float) for std in history["std"]))
for params in history["parameters"]:
self.assertTrue(all(isinstance(param, float) for param in params))
def test_missing_varform_params(self):
"""Test specifying a variational form with no parameters raises an error."""
circuit = QuantumCircuit(self.h2_op.num_qubits)
vqd = VQD(
k=1,
ansatz=circuit,
quantum_instance=BasicAer.get_backend("statevector_simulator"))
with self.assertRaises(RuntimeError):
vqd.compute_eigenvalues(operator=self.h2_op)
def test_aux_operator_std_dev_aer_pauli(self):
"""Test non-zero standard deviations of aux operators with AerPauliExpectation."""
wavefunction = self.ry_wavefunction
vqd = VQD(
ansatz=wavefunction,
expectation=AerPauliExpectation(),
optimizer=COBYLA(maxiter=0),
quantum_instance=QuantumInstance(
backend=Aer.get_backend("qasm_simulator"),
shots=1,
seed_simulator=algorithm_globals.random_seed,
seed_transpiler=algorithm_globals.random_seed,
),
)
# Go again with two auxiliary operators
aux_op1 = PauliSumOp.from_list([("II", 2.0)])
aux_op2 = PauliSumOp.from_list([("II", 0.5), ("ZZ", 0.5), ("YY", 0.5),
("XX", -0.5)])
aux_ops = [aux_op1, aux_op2]
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=aux_ops)
self.assertEqual(len(result.aux_operator_eigenvalues), 2)
# expectation values
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][0],
2.0,
places=1)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][0],
0.6698863565455391,
places=1)
# standard deviations
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1],
0.0,
places=6)
# Go again with additional None and zero operators
aux_ops = [*aux_ops, None, 0]
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=aux_ops)
self.assertEqual(len(result.aux_operator_eigenvalues[-1]), 4)
# expectation values
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][0],
2.0,
places=6)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][0],
0.6036400943063891,
places=6)
self.assertEqual(result.aux_operator_eigenvalues[0][2][0], 0.0)
self.assertEqual(result.aux_operator_eigenvalues[0][3][0], 0.0)
# standard deviations
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1],
0.0,
places=6)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][2][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][3][1], 0.0)
def test_aux_operators_list(self):
"""Test list-based aux_operators."""
wavefunction = self.ry_wavefunction
vqd = VQD(k=2,
ansatz=wavefunction,
quantum_instance=self.statevector_simulator)
# Start with an empty list
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=[])
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=2)
self.assertIsNone(result.aux_operator_eigenvalues)
# Go again with two auxiliary operators
aux_op1 = PauliSumOp.from_list([("II", 2.0)])
aux_op2 = PauliSumOp.from_list([("II", 0.5), ("ZZ", 0.5), ("YY", 0.5),
("XX", -0.5)])
aux_ops = [aux_op1, aux_op2]
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=aux_ops)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=2)
self.assertEqual(len(result.aux_operator_eigenvalues), 2)
# expectation values
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][0],
2,
places=2)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][0],
0,
places=2)
# standard deviations
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1], 0.0)
# Go again with additional None and zero operators
extra_ops = [*aux_ops, None, 0]
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=extra_ops)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=2)
self.assertEqual(len(result.aux_operator_eigenvalues), 2)
# expectation values
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][0],
2,
places=2)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][0],
0,
places=2)
self.assertEqual(result.aux_operator_eigenvalues[0][2][0], 0.0)
self.assertEqual(result.aux_operator_eigenvalues[0][3][0], 0.0)
# standard deviations
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][0][1], 0.0)
self.assertAlmostEqual(result.aux_operator_eigenvalues[0][1][1], 0.0)
self.assertEqual(result.aux_operator_eigenvalues[0][3][1], 0.0)
def test_basic_aer_statevector(self):
"""Test the VQD on BasicAer's statevector simulator."""
wavefunction = self.ryrz_wavefunction
vqd = VQD(
k=2,
ansatz=wavefunction,
optimizer=COBYLA(),
quantum_instance=QuantumInstance(
BasicAer.get_backend("statevector_simulator"),
basis_gates=["u1", "u2", "u3", "cx", "id"],
coupling_map=[[0, 1]],
seed_simulator=algorithm_globals.random_seed,
seed_transpiler=algorithm_globals.random_seed,
),
)
result = vqd.compute_eigenvalues(operator=self.h2_op)
with self.subTest(msg="test eigenvalue"):
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=1)
with self.subTest(msg="test dimension of optimal point"):
self.assertEqual(len(result.optimal_point[-1]), 8)
with self.subTest(msg="assert cost_function_evals is set"):
self.assertIsNotNone(result.cost_function_evals)
with self.subTest(msg="assert optimizer_time is set"):
self.assertIsNotNone(result.optimizer_time)
def test_with_aer_qasm_snapshot_mode(self):
"""Test the VQD using Aer's qasm_simulator snapshot mode."""
backend = Aer.get_backend("aer_simulator")
optimizer = COBYLA(maxiter=400)
wavefunction = self.ryrz_wavefunction
quantum_instance = QuantumInstance(
backend,
shots=100,
seed_simulator=algorithm_globals.random_seed,
seed_transpiler=algorithm_globals.random_seed,
)
vqd = VQD(
k=2,
ansatz=wavefunction,
optimizer=optimizer,
expectation=AerPauliExpectation(),
quantum_instance=quantum_instance,
)
result = vqd.compute_eigenvalues(operator=self.test_op)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.test_results,
decimal=1)
def test_with_aer_qasm(self):
"""Test VQD with Aer's qasm_simulator."""
backend = Aer.get_backend("aer_simulator")
optimizer = COBYLA(maxiter=1000)
wavefunction = self.ry_wavefunction
quantum_instance = QuantumInstance(
backend,
seed_simulator=algorithm_globals.random_seed,
seed_transpiler=algorithm_globals.random_seed,
)
vqd = VQD(
k=2,
ansatz=wavefunction,
optimizer=optimizer,
expectation=PauliExpectation(),
quantum_instance=quantum_instance,
)
result = vqd.compute_eigenvalues(operator=self.h2_op)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=1)
def test_mismatching_num_qubits(self):
"""Ensuring circuit and operator mismatch is caught"""
wavefunction = QuantumCircuit(1)
optimizer = SLSQP(maxiter=50)
vqd = VQD(
k=1,
ansatz=wavefunction,
optimizer=optimizer,
quantum_instance=self.statevector_simulator,
)
with self.assertRaises(AlgorithmError):
_ = vqd.compute_eigenvalues(operator=self.h2_op)
def test_basic_aer_qasm(self):
"""Test the VQD on BasicAer's QASM simulator."""
optimizer = COBYLA(maxiter=1000)
wavefunction = self.ry_wavefunction
vqd = VQD(
ansatz=wavefunction,
optimizer=optimizer,
max_evals_grouped=1,
quantum_instance=self.qasm_simulator,
)
# TODO benchmark this later.
result = vqd.compute_eigenvalues(operator=self.h2_op)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=1)
def test_with_aer_statevector(self):
"""Test VQD with Aer's statevector_simulator."""
backend = Aer.get_backend("aer_simulator_statevector")
wavefunction = self.ry_wavefunction
optimizer = L_BFGS_B()
quantum_instance = QuantumInstance(
backend,
seed_simulator=algorithm_globals.random_seed,
seed_transpiler=algorithm_globals.random_seed,
)
vqd = VQD(
k=2,
ansatz=wavefunction,
optimizer=optimizer,
max_evals_grouped=1,
quantum_instance=quantum_instance,
)
result = vqd.compute_eigenvalues(operator=self.h2_op)
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=2)
def test_aux_operators_dict(self):
"""Test dictionary compatibility of aux_operators"""
wavefunction = self.ry_wavefunction
vqd = VQD(ansatz=wavefunction,
quantum_instance=self.statevector_simulator)
# Start with an empty dictionary
result = vqd.compute_eigenvalues(self.h2_op, aux_operators={})
np.testing.assert_array_almost_equal(result.eigenvalues.real,
self.h2_energy_excited,
decimal=2)
self.assertIsNone(result.aux_operator_eigenvalues)
# Go again with two auxiliary operators
aux_op1 = PauliSumOp.from_list([("II", 2.0)])
aux_op2 = PauliSumOp.from_list([("II", 0.5), ("ZZ", 0.5), ("YY", 0.5),
("XX", -0.5)])
aux_ops = {"aux_op1": aux_op1, "aux_op2": aux_op2}
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=aux_ops)
self.assertEqual(len(result.eigenvalues), 2)
self.assertEqual(len(result.eigenstates), 2)
self.assertEqual(result.eigenvalues.dtype, np.complex128)
self.assertAlmostEqual(result.eigenvalues[0], -1.85727503)
self.assertEqual(len(result.aux_operator_eigenvalues), 2)
self.assertEqual(len(result.aux_operator_eigenvalues[0]), 2)
# expectation values
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op1"][0], 2, places=6)
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op2"][0], 0, places=1)
# standard deviations
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op1"][1], 0.0)
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op2"][1], 0.0)
# Go again with additional None and zero operators
extra_ops = {**aux_ops, "None_operator": None, "zero_operator": 0}
result = vqd.compute_eigenvalues(self.h2_op, aux_operators=extra_ops)
self.assertEqual(len(result.eigenvalues), 2)
self.assertEqual(len(result.eigenstates), 2)
self.assertEqual(result.eigenvalues.dtype, np.complex128)
self.assertAlmostEqual(result.eigenvalues[0], -1.85727503)
self.assertEqual(len(result.aux_operator_eigenvalues), 2)
self.assertEqual(len(result.aux_operator_eigenvalues[0]), 3)
# expectation values
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op1"][0], 2, places=6)
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op2"][0], 0, places=6)
self.assertEqual(
result.aux_operator_eigenvalues[0]["zero_operator"][0], 0.0)
self.assertTrue(
"None_operator" not in result.aux_operator_eigenvalues[0].keys())
# standard deviations
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op1"][1], 0.0)
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["aux_op2"][1], 0.0)
self.assertAlmostEqual(
result.aux_operator_eigenvalues[0]["zero_operator"][1], 0.0)