def _check_is_diagonal(operator: OperatorBase) -> bool:
"""Check whether ``operator`` is diagonal.
Args:
operator: The operator to check for diagonality.
Returns:
True, if the operator is diagonal, False otherwise.
Raises:
OpflowError: If the operator is not diagonal.
"""
if isinstance(operator, PauliOp):
# every X component must be False
return not np.any(operator.primitive.x)
# For sums (PauliSumOp and SummedOp), we cover the case of sums of diagonal paulis, but don't
# raise since there might be summand canceling the non-diagonal parts. That case is checked
# in the inefficient matrix check at the bottom.
if isinstance(operator, PauliSumOp):
if not np.any(operator.primitive.paulis.x):
return True
elif isinstance(operator, SummedOp):
if all(
isinstance(op, PauliOp) and not np.any(op.primitive.x)
for op in operator.oplist):
return True
elif isinstance(operator, ListOp):
return all(operator.traverse(_check_is_diagonal))
# cannot efficiently check if a operator is diagonal, converting to matrix
matrix = operator.to_matrix()
return np.all(matrix == np.diag(np.diagonal(matrix)))
def convert(self, operator: OperatorBase) -> OperatorBase:
"""Convert the Operator to ``CircuitStateFns``, recursively if ``traverse`` is True.
Args:
operator: The Operator to convert
Returns:
The converted Operator.
"""
if isinstance(operator, DictStateFn) and self._convert_dicts:
return CircuitStateFn.from_dict(operator.primitive)
if isinstance(operator, VectorStateFn) and self._convert_vectors:
return CircuitStateFn.from_vector(operator.to_matrix(massive=True))
elif isinstance(operator,
ListOp) and "Dict" in operator.primitive_strings():
return operator.traverse(self.convert)
else:
return operator
def _check_is_diagonal(operator: OperatorBase) -> bool:
"""Check whether ``operator`` is diagonal.
Args:
operator: The operator to check for diagonality.
Returns:
True, if the operator is diagonal, False otherwise.
Raises:
OpflowError: If the operator is not diagonal.
"""
if isinstance(operator, PauliOp):
# every X component must be False
if not np.any(operator.primitive.x):
return True
return False
if isinstance(operator, SummedOp):
# cover the case of sums of diagonal paulis, but don't raise since there might be summands
# canceling the non-diagonal parts
# ignoring mypy since we know that all operators are PauliOps
if all(
isinstance(op, PauliOp) and not np.any(op.primitive.x)
for op in operator.oplist):
return True
if isinstance(operator, ListOp):
return all(operator.traverse(_check_is_diagonal))
# cannot efficiently check if a operator is diagonal, converting to matrix
matrix = operator.to_matrix()
if np.all(matrix == np.diag(np.diagonal(matrix))):
return True
return False
