def test_tomography_plot_raises_for_incorrect_number_of_axes():
simulator = sim.Simulator()
qubit = GridQubit(0, 0)
circuit = circuits.Circuit(ops.X(qubit)**0.5)
result = single_qubit_state_tomography(simulator, qubit, circuit, 1000)
with pytest.raises(TypeError): # ax is not a List[plt.Axes]
ax = plt.subplot()
result.plot(ax)
with pytest.raises(ValueError):
_, axes = plt.subplots(1, 3)
result.plot(axes)
def test_single_qubit_state_tomography():
# Check that the density matrices of the output states of X/2, Y/2 and
# H + Y gates closely match the ideal cases.
simulator = sim.Simulator()
qubit = GridQubit(0, 0)
circuit_1 = circuits.Circuit(ops.X(qubit)**0.5)
circuit_2 = circuits.Circuit(ops.Y(qubit)**0.5)
circuit_3 = circuits.Circuit(ops.H(qubit), ops.Y(qubit))
act_rho_1 = single_qubit_state_tomography(simulator, qubit, circuit_1,
1000).data
act_rho_2 = single_qubit_state_tomography(simulator, qubit, circuit_2,
1000).data
act_rho_3 = single_qubit_state_tomography(simulator, qubit, circuit_3,
1000).data
tar_rho_1 = np.array([[0.5, 0.5j], [-0.5j, 0.5]])
tar_rho_2 = np.array([[0.5, 0.5], [0.5, 0.5]])
tar_rho_3 = np.array([[0.5, -0.5], [-0.5, 0.5]])
np.testing.assert_almost_equal(act_rho_1, tar_rho_1, decimal=1)
np.testing.assert_almost_equal(act_rho_2, tar_rho_2, decimal=1)
np.testing.assert_almost_equal(act_rho_3, tar_rho_3, decimal=1)