def test_reduce_terms(self):
"""Test reduce_terms function using LiH Hamiltonian."""
hamiltonian, spectrum = lih_hamiltonian()
qubit_hamiltonian = jordan_wigner(hamiltonian)
stab1 = QubitOperator('Z0 Z2', -1.0)
stab2 = QubitOperator('Z1 Z3', -1.0)
red_eigenspectrum = eigenspectrum(
reduce_number_of_terms(qubit_hamiltonian, stab1 + stab2))
self.assertAlmostEqual(spectrum[0], red_eigenspectrum[0])
def test_reduce_terms_manual_input(self):
"""Test reduce_terms function using LiH Hamiltonian."""
hamiltonian, spectrum = lih_hamiltonian()
qubit_hamiltonian = jordan_wigner(hamiltonian)
stab1 = QubitOperator('Z0 Z2', -1.0)
stab2 = QubitOperator('Z1 Z3', -1.0)
red_eigenspectrum = eigenspectrum(
reduce_number_of_terms(qubit_hamiltonian, [stab1, stab2],
manual_input=True,
fixed_positions=[0, 1]))
self.assertAlmostEqual(spectrum[0], red_eigenspectrum[0])
def test_function_errors(self):
"""Test error of main function."""
hamiltonian, spectrum = lih_hamiltonian()
qubit_hamiltonian = jordan_wigner(hamiltonian)
stab1 = QubitOperator('Z0 Z2', -1.0)
stab2 = QubitOperator('Z1 Z3', -1.0)
with self.assertRaises(TypeError):
reduce_number_of_terms(operator=1, stabilizers=stab1 + stab2)
with self.assertRaises(TypeError):
reduce_number_of_terms(operator=qubit_hamiltonian, stabilizers=1)
with self.assertRaises(TypeError):
reduce_number_of_terms(operator=qubit_hamiltonian,
stabilizers=stab1 + stab2,
manual_input=True,
fixed_positions=None)
with self.assertRaises(StabilizerError):
reduce_number_of_terms(operator=qubit_hamiltonian,
stabilizers=stab1 + stab2,
manual_input=True,
fixed_positions=[1])
with self.assertRaises(StabilizerError):
reduce_number_of_terms(operator=qubit_hamiltonian,
stabilizers=stab1 + stab2,
manual_input=True,
fixed_positions=[1, 1])
with self.assertRaises(StabilizerError):
# Check Identity as stabilizer error.
reduce_number_of_terms(operator=qubit_hamiltonian,
stabilizers=(stab1 +
QubitOperator(' ', 1.0)))
with self.assertRaises(StabilizerError):
# Check complex coefficient stabilizer error.
reduce_number_of_terms(operator=qubit_hamiltonian,
stabilizers=(stab1 +
QubitOperator('Z0', 1.0j)))
with self.assertRaises(StabilizerError):
# Check linearly-dependent stabilizer error.
reduce_number_of_terms(
operator=qubit_hamiltonian,
stabilizers=(stab1 + QubitOperator('Z0 Z1 Z2 Z3', 1.0) +
stab2))
with self.assertRaises(StabilizerError):
# Check anti-commuting stabilizer error.
reduce_number_of_terms(operator=qubit_hamiltonian,
stabilizers=(QubitOperator('X0', 1.0) +
QubitOperator('Y0', 1.0)))
with self.assertRaises(StabilizerError):
# Check linearly-dependent stabilizer error.
_reduce_terms(
terms=qubit_hamiltonian,
stabilizer_list=list(stab1 +
QubitOperator('Z0 Z1 Z2 Z3', 1.0) +
stab2),
manual_input=False,
fixed_positions=[])
with self.assertRaises(StabilizerError):
# Check complex coefficient stabilizer error.
_reduce_terms(terms=qubit_hamiltonian,
stabilizer_list=list(stab1 +
QubitOperator('Z0', 1.0j)),
manual_input=False,
fixed_positions=[])
with self.assertRaises(StabilizerError):
# Check linearly-dependent stabilizer error.
par_qop = QubitOperator('Z0 Z1 Z2 Z3', 1.0)
_reduce_terms_keep_length(terms=qubit_hamiltonian,
stabilizer_list=[stab1, par_qop, stab2],
manual_input=False,
fixed_positions=[])
with self.assertRaises(StabilizerError):
# Check complex coefficient stabilizer error.
aux_qop = QubitOperator('Z0', 1.0j)
_reduce_terms_keep_length(terms=qubit_hamiltonian,
stabilizer_list=[stab1, aux_qop],
manual_input=False,
fixed_positions=[])
with self.assertRaises(StabilizerError):
# Test check_commuting_stabilizer function
# Requires a list of QubitOperators one of which
# has an imaginary term.
check_commuting_stabilizers(stabilizer_list=[
QubitOperator('Z0 Z1', 1.0),
QubitOperator('X0', 1j)
],
msg='This test fails.')
with self.assertRaises(StabilizerError):
# Test check_stabilizer_linearity function.
# Requires a list of QUbitOperators one of which is
# the identity.
check_stabilizer_linearity(
[QubitOperator('Z0 Z1', 1.0),
QubitOperator(' ', 1.0)],
msg='This test fails.')