def test_get_params_for_setting():
qubits = cirq.LineQubit.range(3)
a, b, c = qubits
init_state = cirq.KET_PLUS(a) * cirq.KET_ZERO(b)
observable = cirq.X(a) * cirq.Y(b)
setting = cw.InitObsSetting(init_state=init_state, observable=observable)
padded_setting = _pad_setting(setting, qubits=qubits)
assert padded_setting.init_state == cirq.KET_PLUS(a) * cirq.KET_ZERO(
b) * cirq.KET_ZERO(c)
assert padded_setting.observable == cirq.X(a) * cirq.Y(b) * cirq.Z(c)
assert init_state == cirq.KET_PLUS(a) * cirq.KET_ZERO(b)
assert observable == cirq.X(a) * cirq.Y(b)
needs_init_layer = True
with pytest.raises(ValueError):
_get_params_for_setting(
padded_setting,
flips=[0, 0],
qubits=qubits,
needs_init_layer=needs_init_layer,
)
params = _get_params_for_setting(
padded_setting,
flips=[0, 0, 1],
qubits=qubits,
needs_init_layer=needs_init_layer,
)
assert all(x in params for x in [
'0-Xf',
'0-Yf',
'1-Xf',
'1-Yf',
'2-Xf',
'2-Yf',
'0-Xi',
'0-Yi',
'1-Xi',
'1-Yi',
'2-Xi',
'2-Yi',
])
circuit = cirq.Circuit(cirq.I.on_each(*qubits))
circuit = _with_parameterized_layers(
circuit,
qubits=qubits,
needs_init_layer=needs_init_layer,
)
circuit = circuit[:-1] # remove measurement so we can compute <Z>
psi = cirq.Simulator().simulate(circuit, param_resolver=params)
ma = cirq.Z(a).expectation_from_state_vector(psi.final_state_vector,
qubit_map=psi.qubit_map)
mb = cirq.Z(b).expectation_from_state_vector(psi.final_state_vector,
qubit_map=psi.qubit_map)
mc = cirq.Z(c).expectation_from_state_vector(psi.final_state_vector,
qubit_map=psi.qubit_map)
np.testing.assert_allclose([ma, mb, mc], [1, 0, -1])
def test_params_and_settings():
qubits = cirq.LineQubit.range(1)
(q, ) = qubits
tests = [
(cirq.KET_ZERO, cirq.Z, 1),
(cirq.KET_ONE, cirq.Z, -1),
(cirq.KET_PLUS, cirq.X, 1),
(cirq.KET_MINUS, cirq.X, -1),
(cirq.KET_IMAG, cirq.Y, 1),
(cirq.KET_MINUS_IMAG, cirq.Y, -1),
(cirq.KET_ZERO, cirq.Y, 0),
]
for init, obs, coef in tests:
setting = cw.InitObsSetting(init_state=init(q), observable=obs(q))
circuit = cirq.Circuit(cirq.I.on_each(*qubits))
circuit = _with_parameterized_layers(circuit,
qubits=qubits,
needs_init_layer=True)
params = _get_params_for_setting(setting,
flips=[False],
qubits=qubits,
needs_init_layer=True)
circuit = circuit[:-1] # remove measurement so we can compute <Z>
psi = cirq.Simulator().simulate(circuit, param_resolver=params)
z = cirq.Z(q).expectation_from_state_vector(psi.final_state_vector,
qubit_map=psi.qubit_map)
assert np.abs(coef - z) < 1e-2, f'{init} {obs} {coef}'
