- class ListOp(oplist, combo_fn=None, coeff=1.0, abelian=False, grad_combo_fn=None)¶
Deprecated: A Class for manipulating List Operators, and parent class to
List Operators are classes for storing and manipulating lists of Operators, State functions, or Measurements, and include some rule or
combo_fndefining how the Operator functions of the list constituents should be combined to form to cumulative Operator function of the
ListOp. For example, a
SummedOphas an addition-based
combo_fn, so once the Operators in its list are evaluated against some bitstring to produce a list of results, we know to add up those results to produce the final result of the
SummedOp's evaluation. In theory, this
combo_fncan be any function over classical complex values, but for convenience we've chosen for them to be defined over NumPy arrays and values. This way, large numbers of evaluations, such as after calling
to_matrixon the list constituents, can be efficiently combined. While the combination function is defined over classical values, it should be understood as the operation by which each Operators' underlying function is combined to form the underlying Operator function of the
ListOp. In this way, the
ListOpsare the basis for constructing large and sophisticated Operators, State Functions, and Measurements.
ListOpclass is particularly interesting, as its
combo_fnis "the identity list Operation". Meaning, if we understand the
combo_fnas a function from a list of complex values to some output, one such function is returning the list as-is. This is powerful for constructing compact hierarchical Operators which return many measurements in multiple dimensional lists.
Deprecated since version 0.24.0: The class
qiskit.opflow.list_ops.list_op.ListOpis deprecated as of qiskit-terra 0.24.0. It will be removed no earlier than 3 months after the release date. For code migration guidelines, visit https://qisk.it/opflow_migration.
oplist (Sequence[OperatorBase]) -- The list of
OperatorBasesdefining this Operator's underlying function.
combo_fn (Optional[Callable]) -- The recombination function to combine classical results of the
oplistOperators' eval functions (e.g. sum). Default is lambda x: x.
coeff (Union[complex, ParameterExpression]) -- A coefficient multiplying the operator
abelian (bool) -- Indicates whether the Operators in
oplistare known to mutually commute.
grad_combo_fn (Optional[Callable]) -- The gradient of recombination function. If None, the gradient will be computed automatically.
the (Note that the default "recombination function" lambda above is essentially) --
values (identity - it accepts the list of) --
list. (and returns them in a) --
Methods Defined Here
Return Operator addition of self and other, overloaded by
Return a new Operator equal to the Operator's adjoint (conjugate transpose), overloaded by
Binds scalar values to any Terra
Parametersin the coefficients or primitives of the Operator, or substitutes one
Return Operator Composition between self and other (linear algebra-style: A@B(x) = A(B(x))), overloaded by
ListOp default combo function i.e. lambda x: x.
Evaluate Equality between Operators, overloaded by
Evaluate the Operator's underlying function, either on a binary string or another Operator.
OperatorBaseequivalent to an exponentiation of self * -i, e^(-i*op).
MatrixOpequivalent to log(H)/-i for this operator H.
Returns the scalar multiplication of the Operator, overloaded by
*, including support for Terra's
Parameters, which can be bound to values later (via
Permute the qubits of the operator.
Return Operator composed with self multiple times, overloaded by
Return a set of strings describing the primitives contained in the Operator.
Try collapsing the Operator structure, usually after some type of conversion, e.g.
Return tensor product between self and other, overloaded by
Return tensor product with self multiple times, overloaded by
Returns an equivalent Operator composed of only QuantumCircuit-based primitives, such as
Return NumPy representation of the Operator.
Returns an equivalent Operator composed of only NumPy-based primitives, such as
Returns an equivalent Operator composed of only Pauli-based primitives, such as
Returns SciPy sparse matrix representation of the Operator.
Apply the convert_fn to each node in the oplist.
- INDENTATION = ' '¶
Whether the Operators in
oplistare known to commute with one another.
A bool indicating whether the
The scalar coefficient multiplying the Operator.
Return a list of the coefficients of the operators listed. Raises exception for nested Listops.
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
The combination function.
Indicates whether the ListOp or subclass is distributive under composition. ListOp and SummedOp are, meaning that (opv @ op) = (opv @ op + opv @ op) (using plus for SummedOp, list for ListOp, etc.), while ComposedOp and TensoredOp do not behave this way.
A bool indicating whether the ListOp is distributive under composition.
The gradient of
Return the unique instance id.
The list of
OperatorBasesdefining the underlying function of this Operator.
The Operators defining the ListOp