def test_is_povm_false_not_sum_identity():
"""Test if invalid POVM (does not sum to identity)."""
non_meas_1 = np.array([[1, 0], [0, 1]])
non_meas_2 = np.array([[1, 0], [0, 1]])
non_meas = [non_meas_1, non_meas_2]
np.testing.assert_equal(is_povm(non_meas), False)
def test_is_povm_true():
"""Test if valid measurement returns True."""
dim, num_inputs, num_outputs = 2, 2, 2
measurements = random_povm(dim, num_inputs, num_outputs)
np.testing.assert_equal(
is_povm([measurements[:, :, 0, 0], measurements[:, :, 0, 1]]), True)
def test_is_povm_false():
"""Test if invalid POVM returns False."""
non_meas_1 = np.array([[1, 2], [3, 4]])
non_meas_2 = np.array([[5, 6], [7, 8]])
non_meas = [non_meas_1, non_meas_2]
np.testing.assert_equal(is_povm(non_meas), False)