def test_PrepareAndMeasureOnWFSim_QubitPlaceholders():
q1, q2 = QubitPlaceholder(), QubitPlaceholder()
p = Program()
params = p.declare("params", memory_type="REAL", memory_size=2)
p.inst(RX(params[0], q1))
p.inst(RX(params[1], q2))
def make_memory_map(params):
return {"params": params}
ham = PauliSum([PauliTerm("Z", q1), PauliTerm("Z", q2)])
qubit_mapping = get_default_qubit_mapping(p)
sim = WavefunctionSimulator()
with local_qvm():
cost_fn = PrepareAndMeasureOnWFSim(
p,
make_memory_map,
ham,
sim,
enable_logging=True,
qubit_mapping=qubit_mapping,
scalar_cost_function=False,
)
out = cost_fn([np.pi, np.pi / 2], nshots=100)
assert np.allclose(cost_fn.log[0].fun, (-1.0, 0.1))
assert np.allclose(out, (-1, 0.1))
def test_PrepareAndMeasureOnQVM_QubitPlaceholders_nondiag_hamiltonian():
q1, q2, q3 = QubitPlaceholder(), QubitPlaceholder(), QubitPlaceholder()
ham = PauliTerm("Y", q1) * PauliTerm("Z", q3)
ham += PauliTerm("Y", q1) * PauliTerm("Z", q2, -0.3)
ham += PauliTerm("Y", q1) * PauliTerm("X", q3, 2.0)
params = [3.0, 0.4, 4.5]
prepare_ansatz = Program()
param_register = prepare_ansatz.declare("params",
memory_type="REAL",
memory_size=3)
prepare_ansatz.inst(RX(param_register[0], q1))
prepare_ansatz.inst(RY(param_register[1], q2))
prepare_ansatz.inst(RY(param_register[2], q3))
def make_memory_map(params):
return {"params": params}
qubit_mapping = get_default_qubit_mapping(prepare_ansatz)
qvm = get_qc("3q-qvm")
with local_qvm():
cost_fn = PrepareAndMeasureOnQVM(prepare_ansatz,
make_memory_map,
qvm=qvm,
hamiltonian=ham,
scalar_cost_function=False,
base_numshots=100,
qubit_mapping=qubit_mapping)
out = cost_fn(params, nshots=10)
assert np.allclose(out, (0.346, 0.07), rtol=1.1)
def test_PrepareAndMeasureOnQVM_QubitPlaceholders():
q1, q2 = QubitPlaceholder(), QubitPlaceholder()
prepare_ansatz = Program()
param_register = prepare_ansatz.declare("params",
memory_type="REAL",
memory_size=2)
prepare_ansatz.inst(RX(param_register[0], q1))
prepare_ansatz.inst(RX(param_register[1], q2))
def make_memory_map(params):
return {"params": params}
ham = PauliSum([PauliTerm("Z", q1), PauliTerm("Z", q2)])
qubit_mapping = get_default_qubit_mapping(prepare_ansatz)
qvm = get_qc("2q-qvm")
with local_qvm():
# qvm = proc.qvm
cost_fn = PrepareAndMeasureOnQVM(prepare_ansatz,
make_memory_map,
qvm=qvm,
hamiltonian=ham,
enable_logging=True,
scalar_cost_function=False,
base_numshots=10,
qubit_mapping=qubit_mapping)
out = cost_fn([np.pi, np.pi / 2], nshots=10)
assert np.allclose(cost_fn.log[0].fun, (-1.0, 0.1), rtol=1.1)
assert np.allclose(out, (-1, 0.1), rtol=1.1)
def test_exponentiate_2():
# testing general 2-circuit
q = QubitPlaceholder.register(8)
generator = PauliTerm("Z", q[0], 1.0) * PauliTerm("Z", q[1], 1.0)
para_prog = exponential_map(generator)
prog = para_prog(1)
result_prog = Program().inst(CNOT(q[0], q[1])).inst(RZ(2.0, q[1])).inst(CNOT(q[0], q[1]))
mapping = get_default_qubit_mapping(prog)
assert address_qubits(prog, mapping) == address_qubits(result_prog, mapping)
def test_vqe_on_WFSim_QubitPlaceholders():
qubit_mapping = get_default_qubit_mapping(prepare_ansatz)
sim = WavefunctionSimulator()
cost_fun = PrepareAndMeasureOnWFSim(
prepare_ansatz=prepare_ansatz,
make_memory_map=lambda p: {"params": p},
hamiltonian=hamiltonian,
sim=sim,
scalar_cost_function=True,
qubit_mapping=qubit_mapping)
out = scipy.optimize.minimize(cost_fun, p0, tol=1e-3, method="Cobyla")
print(out)
prog = address_qubits(prepare_ansatz, qubit_mapping=qubit_mapping)
wf = sim.wavefunction(prog, {"params": out['x']})
print(wf.probabilities())
assert np.allclose(np.abs(wf.amplitudes**2), [0, 0, 0, 1],
rtol=1.5,
atol=0.01)
assert np.allclose(out['fun'], -4)
assert out['success']
