def test_execute_with_cdr(circuit_type):
circuit = random_x_z_circuit(LineQubit.range(2),
n_moments=2,
random_state=1)
circuit = convert_from_mitiq(circuit, circuit_type)
# Define observables for testing.
sigma_z = np.diag([1, -1])
obs = np.kron(np.identity(2), sigma_z)
obs2 = np.kron(sigma_z, sigma_z)
obs_list = [np.diag(obs), np.diag(obs2)]
exact_solution = [
calculate_observable(simulator_statevector(circuit), observable=obs)
for obs in obs_list
]
kwargs = {
"method_select": "gaussian",
"method_replace": "gaussian",
"sigma_select": 0.5,
"sigma_replace": 0.5,
"random_state": 1,
}
num_circuits = 4
frac_non_cliff = 0.5
noisy_executor = partial(executor, noise_level=0.5)
results0 = execute_with_cdr(
circuit,
noisy_executor,
simulator_statevector,
obs_list,
num_circuits,
frac_non_cliff,
full_output=True,
)
results1 = execute_with_cdr(
circuit,
noisy_executor,
simulator_statevector,
obs_list,
num_circuits,
frac_non_cliff,
ansatz=linear_fit_function_no_intercept,
num_fit_parameters=1,
scale_noise=fold_gates_from_left,
scale_factors=[3],
full_output=True,
**kwargs,
)
for results in [results0, results1]:
for i in range(len(results[1])):
assert abs(results[1][i][0] -
exact_solution[i]) >= abs(results[0][i] -
exact_solution[i])
def test_no_num_fit_parameters_with_custom_fit_raises_error():
with pytest.raises(ValueError, match="Must provide `num_fit_parameters`"):
execute_with_cdr(
random_x_z_cnot_circuit(LineQubit.range(2),
n_moments=2,
random_state=1),
execute,
observables=Observable(PauliString()),
simulator=simulate,
fit_function=lambda _: 1,
)
def test_execute_with_cdr_using_clifford_circuit():
a, b = cirq.LineQubit.range(2)
clifCirc = cirq.Circuit(
cirq.H.on(a),
cirq.H.on(b),
)
obs = Observable(PauliString("XZ"), PauliString("YY"))
cdr_value = execute_with_cdr(clifCirc,
observable=obs,
executor=execute,
simulator=simulate)
assert obs.expectation(clifCirc, simulate) == cdr_value
def test_execute_with_variable_noise_cdr(circuit_type):
circuit = random_x_z_cnot_circuit(LineQubit.range(2),
n_moments=5,
random_state=1)
circuit = convert_from_mitiq(circuit, circuit_type)
obs = Observable(PauliString("IZ"), PauliString("ZZ"))
true_value = obs.expectation(circuit, simulate)
noisy_value = obs.expectation(circuit, execute)
vncdr_value = execute_with_cdr(
circuit,
execute,
obs,
simulator=simulate,
num_training_circuits=10,
fraction_non_clifford=0.5,
scale_factors=[1, 3],
random_state=1,
)
assert abs(vncdr_value - true_value) <= abs(noisy_value - true_value)
def test_execute_with_cdr(circuit_type, fit_function, kwargs, random_state):
circuit = random_x_z_cnot_circuit(
LineQubit.range(2),
n_moments=5,
random_state=random_state,
)
circuit = convert_from_mitiq(circuit, circuit_type)
obs = Observable(PauliString("XZ"), PauliString("YY"))
true_value = obs.expectation(circuit, simulate)
noisy_value = obs.expectation(circuit, execute)
cdr_value = execute_with_cdr(
circuit,
execute,
obs,
simulator=simulate,
num_training_circuits=20,
fraction_non_clifford=0.5,
fit_function=fit_function,
random_state=random_state,
**kwargs,
)
assert abs(cdr_value - true_value) <= abs(noisy_value - true_value)