AbelianGrouper
class AbelianGrouper(traverse=True)
Bases: qiskit.opflow.converters.converter_base.ConverterBase
The AbelianGrouper converts SummedOps into a sum of Abelian sums.
Meaning, it will traverse the Operator, and when it finds a SummedOp, it will evaluate which of the summed sub-Operators commute with one another. It will then convert each of the groups of commuting Operators into their own SummedOps, and return the sum-of-commuting-SummedOps. This is particularly useful for cases where mutually commuting groups can be handled similarly, as in the case of Pauli Expectations, where commuting Paulis have the same diagonalizing circuit rotation, or Pauli Evolutions, where commuting Paulis can be diagonalized together.
Parameters
traverse (bool) – Whether to convert only the Operator passed to convert, or traverse down that Operator.
Methods Defined Here
convert
AbelianGrouper.convert(operator)
Check if operator is a SummedOp, in which case covert it into a sum of mutually commuting sums, or if the Operator contains sub-Operators and traverse is True, attempt to convert any sub-Operators.
Parameters
operator (OperatorBase) – The Operator to attempt to convert.
Return type
OperatorBase
Returns
The converted Operator.
group_subops
classmethod AbelianGrouper.group_subops(list_op)
Given a ListOp, attempt to group into Abelian ListOps of the same type.
Parameters
list_op (Union[ListOp, PauliSumOp]) – The Operator to group into Abelian groups
Return type
ListOp
Returns
The grouped Operator.
Raises
OpflowError – If any of list_op’s sub-ops is not PauliOp.