Estimator

class Estimator(circuits: Iterable[QuantumCircuit] | QuantumCircuit | None = None, observables: Iterable[SparsePauliOp] | SparsePauliOp | None = None, parameters: Iterable[Iterable[Parameter]] | None = None, **kwargs)

Bases: qiskit.primitives.base.base_estimator.BaseEstimator

Reference implementation of BaseEstimator.

Run Options

• shots (None or int) – The number of shots. If None, it calculates the exact expectation values. Otherwise, it samples from normal distributions with standard errors as standard deviations using normal distribution approximation.

• seed (np.random.Generator or int) – Set a fixed seed or generator for the normal distribution. If shots is None, this option is ignored.

Parameters

• circuits – circuits that represent quantum states.

• observables – observables to be estimated.

• parameters – Parameters of each of the quantum circuits. Defaults to [circ.parameters for circ in circuits].

• options – Default options.

Raises

QiskitError – if some classical bits are not used for measurements.

Methods

close	Close the session and free resources
run	Run the job of the estimation of expectation value(s).
set_options	Set options values for the estimator.

Attributes

circuits

Quantum circuits that represents quantum states.

Returns

The quantum circuits.

observables

Observables to be estimated.

Returns

The observables.

options

Return options values for the estimator.

Return type

Options

Returns

options

parameters

Parameters of the quantum circuits.

Returns

Parameters, where parameters[i][j] is the j-th parameter of the i-th circuit.