def test_transformation_by_pauli(self):
n = NoiseTransformer()
# polarization in the XY plane; we represent via Kraus operators
X = self.ops['X']
Y = self.ops['Y']
Z = self.ops['Z']
p = 0.22
theta = numpy.pi / 5
E0 = numpy.sqrt(1 - p) * numpy.array(numpy.eye(2))
E1 = numpy.sqrt(p) * (numpy.cos(theta) * X + numpy.sin(theta) * Y)
results = approximate_quantum_error((E0, E1),
operator_dict={
"X": X,
"Y": Y,
"Z": Z})
expected_results = pauli_error(
[('X', p * numpy.cos(theta) * numpy.cos(theta)),
('Y', p * numpy.sin(theta) * numpy.sin(theta)), ('Z', 0),
('I', 1 - p)])
self.assertErrorsAlmostEqual(expected_results, results)
# now try again without fidelity; should be the same
n.use_honesty_constraint = False
results = approximate_quantum_error((E0, E1),
operator_dict={
"X": X,
"Y": Y,
"Z": Z})
self.assertErrorsAlmostEqual(expected_results, results)
def test_fidelity(self):
n = NoiseTransformer()
expected_fidelity = {'X': 0, 'Y': 0, 'Z': 0, 'H': 0, 'S': 2}
for key in expected_fidelity:
self.assertAlmostEqual(expected_fidelity[key],
n.fidelity([self.ops[key]]),
msg="Wrong fidelity for {}".format(key))
def setUp(self):
self.ops = {
'X': standard_gate_unitary('x'),
'Y': standard_gate_unitary('y'),
'Z': standard_gate_unitary('z'),
'H': standard_gate_unitary('h'),
'S': standard_gate_unitary('s')
}
self.n = NoiseTransformer()