def test_density_matrix_measurement():
"""Check measurement gate on density matrices."""
from qibo.tests.test_measurements import assert_results
original_backend = qibo.get_backend()
qibo.set_backend("matmuleinsum")
state = np.zeros(4)
state[2] = 1
rho = np.outer(state, state.conj())
result = gates.M(0, 1)(rho, nshots=100, is_density_matrix=True)
target_binary_samples = np.zeros((100, 2))
target_binary_samples[:, 0] = 1
assert_results(result,
decimal_samples=2 * np.ones((100,)),
binary_samples=target_binary_samples,
decimal_frequencies={2: 100},
binary_frequencies={"10": 100})
qibo.set_backend(original_backend)
def test_density_matrix_circuit_measurement(backend):
"""Check measurement gate on density matrices using circuit."""
from qibo.tests.test_measurements import assert_results
from qibo.tests.test_measurements import assert_register_results
original_backend = qibo.get_backend()
qibo.set_backend(backend)
state = np.zeros(16)
state[0] = 1
init_rho = np.outer(state, state.conj())
c = models.Circuit(4, density_matrix=True)
c.add(gates.X(1))
c.add(gates.X(3))
c.add(gates.M(0, 1, register_name="A"))
c.add(gates.M(3, 2, register_name="B"))
result = c(init_rho, nshots=100)
target_binary_samples = np.zeros((100, 4))
target_binary_samples[:, 1] = 1
target_binary_samples[:, 2] = 1
assert_results(result,
decimal_samples=6 * np.ones((100, )),
binary_samples=target_binary_samples,
decimal_frequencies={6: 100},
binary_frequencies={"0110": 100})
target = {}
target["decimal_samples"] = {
"A": np.ones((100, )),
"B": 2 * np.ones((100, ))
}
target["binary_samples"] = {
"A": np.zeros((100, 2)),
"B": np.zeros((100, 2))
}
target["binary_samples"]["A"][:, 1] = 1
target["binary_samples"]["B"][:, 0] = 1
target["decimal_frequencies"] = {"A": {1: 100}, "B": {2: 100}}
target["binary_frequencies"] = {"A": {"01": 100}, "B": {"10": 100}}
assert_register_results(result, **target)
qibo.set_backend(original_backend)