ComposedOp¶

class ComposedOp(oplist, coeff=1.0, abelian=False)[source]¶

Bases: qiskit.opflow.list_ops.list_op.ListOp

A class for lazily representing compositions of Operators. Often Operators cannot be efficiently composed with one another, but may be manipulated further so that they can be composed later. This class holds logic to indicate that the Operators in oplist are meant to be composed, and therefore if they reach a point in which they can be, such as after conversion to QuantumCircuits or matrices, they can be reduced by composition.

Parameters

oplist (List[OperatorBase]) – The Operators being composed.
coeff (Union[complex, ParameterExpression]) – A coefficient multiplying the operator
abelian (bool) – Indicates whether the Operators in oplist are known to mutually commute.

Methods Defined Here

`adjoint`	Return a new Operator equal to the Operator's adjoint (conjugate transpose), overloaded by `~`.
`compose`	Return Operator Composition between self and other (linear algebra-style: A@B(x) = A(B(x))), overloaded by `@`.
`eval`	Evaluate the Operator's underlying function, either on a binary string or another Operator.
`non_distributive_reduce`	Reduce without attempting to expand all distributive compositions.
`reduce`	Try collapsing the Operator structure, usually after some type of conversion, e.g.
`to_circuit`	Returns the quantum circuit, representing the composed operator.
`to_matrix`	Return NumPy representation of the Operator.

Attributes

INDENTATION = ' '¶

abelian¶

Whether the Operators in oplist are known to commute with one another.

Return type: bool
Returns: A bool indicating whether the oplist is Abelian.

coeff¶

The scalar coefficient multiplying the Operator.

Return type: Union[complex, ParameterExpression]
Returns: The coefficient.

coeffs¶

Return a list of the coefficients of the operators listed. Raises exception for nested Listops.

Return type: List[Union[complex, ParameterExpression]]

combo_fn¶

The function defining how to combine oplist (or Numbers, or NumPy arrays) to produce the Operator’s underlying function. For example, SummedOp’s combination function is to add all of the Operators in oplist.

Return type: Callable
Returns: The combination function.

distributive¶

Return type: bool

grad_combo_fn¶

The gradient of combo_fn.

Return type: Optional[Callable]

instance_id¶

Return the unique instance id.

Return type: int

num_qubits¶

Return type: int

oplist¶

The list of OperatorBases defining the underlying function of this Operator.

Return type: List[OperatorBase]
Returns: The Operators defining the ListOp

parameters¶

settings¶

Return settings.

Return type: Dict