BaseEstimator
class BaseEstimator(circuits: Iterable[QuantumCircuit] | QuantumCircuit | None = None, observables: Iterable[SparsePauliOp] | SparsePauliOp | None = None, parameters: Iterable[Iterable[Parameter]] | None = None, **kwargs)
Bases: qiskit.primitives.base.base_primitive.BasePrimitive
Estimator base class.
Base class for Estimator that estimates expectation values of quantum circuits and observables.
Creating an instance of an Estimator, or using one in a with context opens a session that holds resources until the instance is close() ed or the context is exited.
Parameters
- circuits – Quantum circuits that represent quantum states.
- observables – Observables.
- parameters – Parameters of quantum circuits, specifying the order in which values will be bound. Defaults to
[circ.parameters for circ in circuits]The indexing is such thatparameters[i, j]is the j-th formal parameter ofcircuits[i]. - options – Default options.
Raises
ValueError – For mismatch of circuits and parameters list.
Methods
close
BaseEstimator.close()
Close the session and free resources
run
BaseEstimator.run(circuits, observables, parameter_values=None, **run_options)
Run the job of the estimation of expectation value(s).
circuits, observables, and parameter_values should have the same length. The i-th element of the result is the expectation of observable
obs = observables[i]for the state prepared by
circ = circuits[i]with bound parameters
values = parameter_values[i].Parameters
- circuits – one or more circuit objects.
- observables – one or more observable objects. Several formats are allowed; importantly,
strshould follow the string representation format forPauliobjects. - parameter_values – concrete parameters to be bound.
- run_options – runtime options used for circuit execution.
Returns
The job object of EstimatorResult.
Raises
- TypeError – Invalid argument type given.
- ValueError – Invalid argument values given.
set_options
BaseEstimator.set_options(**fields)
Set options values for the estimator.
Parameters
**fields – The fields to update the options
Attributes
circuits
Quantum circuits that represents quantum states.
Returns
The quantum circuits.
observables
Observables to be estimated.
Returns
The observables.
options
parameters
Parameters of the quantum circuits.
Returns
Parameters, where parameters[i][j] is the j-th parameter of the i-th circuit.