OperatorStateFn¶

class OperatorStateFn(primitive, coeff=1.0, is_measurement=False)[source]¶

Bases: qiskit.opflow.state_fns.state_fn.StateFn

A class for state functions and measurements which are defined by a density Operator, stored using an OperatorBase.

Parameters

primitive (OperatorBase) – The OperatorBase which defines the behavior of the underlying State function.
coeff (Union[complex, ParameterExpression]) – A coefficient by which to multiply the state function
is_measurement (bool) – Whether the StateFn is a measurement operator

Methods Defined Here

`add`	Return Operator addition of self and other, overloaded by `+`.
`adjoint`	Return a new Operator equal to the Operator’s adjoint (conjugate transpose), overloaded by `~`.
`eval`	Evaluate the Operator’s underlying function, either on a binary string or another Operator.
`permute`	Permute the qubits of the state function.
`primitive_strings`	Return a set of strings describing the primitives contained in the Operator.
`sample`	Sample the state function as a normalized probability distribution.
`tensor`	Return tensor product between self and other, overloaded by `^`.
`to_circuit_op`	Return `StateFnCircuit` corresponding to this StateFn.
`to_density_matrix`	Return numpy matrix of density operator, warn if more than 16 qubits to force the user to set massive=True if they want such a large matrix.
`to_matrix`	Note: this does not return a density matrix, it returns a classical matrix containing the quantum or classical vector representing the evaluation of the state function on each binary basis state.
`to_matrix_op`	Return a MatrixOp for this operator.

Attributes

coeff¶

A coefficient by which the state function is multiplied.

instance_id¶

Return the unique instance id.

is_measurement¶

Whether the StateFn object is a measurement Operator.

num_qubits¶

primitive: qiskit.opflow.operator_base.OperatorBase¶: The primitive which defines the behavior of the underlying State function.

settings¶

Return settings.