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
Estimator.close()
Close the session and free resources
run
Estimator.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
Estimator.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.