qiskit.chemistry.algorithms.pes_samplers.SieveExtrapolator

class SieveExtrapolator(extrapolator=None, window=2, filter_before=True, filter_after=True)

A wrapper extrapolator which clusters the parameter values - either before extrapolation, after, or both - into two large and small clusters, and sets the small clusters』 parameters to zero.

Constructor.

パラメータ

• extrapolator (Union[PolynomialExtrapolator, DifferentialExtrapolator, None]) – 『internal』 extrapolator that performs extrapolation on variational parameters based on data window.

• window (int) – Number of previous points to use for extrapolation.

• filter_before (bool) – Keyword to perform clustering before extrapolation.

• filter_after (bool) – Keyword to perform clustering after extrapolation.

__init__(extrapolator=None, window=2, filter_before=True, filter_after=True)

Constructor.

パラメータ

• extrapolator (Union[PolynomialExtrapolator, DifferentialExtrapolator, None]) – 『internal』 extrapolator that performs extrapolation on variational parameters based on data window.

• window (int) – Number of previous points to use for extrapolation.

• filter_before (bool) – Keyword to perform clustering before extrapolation.

• filter_after (bool) – Keyword to perform clustering after extrapolation.

Methods

__init__([extrapolator, window, …])	Constructor.
extrapolate(points, param_dict)	Extrapolate at specified point of interest given a set of variational parameters.
factory(mode, **kwargs)	Factory method for constructing extrapolators.

extrapolate(points, param_dict)

Extrapolate at specified point of interest given a set of variational parameters. Based on the specified window, a subset of the data points will be used for extrapolation. A default window of 2 points is used, while a value of zero indicates that all previous points will be used for extrapolation. This method finds a cutoff distance based on the maximum average distance or 『gap』 between the average values of the variational parameters. This cutoff distance is used as a criteria to divide the parameters into two clusters by setting all parameters that are below the cutoff distance to zero.

パラメータ

• points (List[float]) – List of point(s) to be used for extrapolation. Can represent some degree of freedom, ex, interatomic distance.

• param_dict (Optional[Dict[float, List[float]]]) – Dictionary of variational parameters. Each key is the point and the value is a list of the variational parameters.

戻り値の型

Dict[float, List[float]]

戻り値

Dictionary of variational parameters for extrapolated point(s).

static factory(mode, **kwargs)

Factory method for constructing extrapolators.

パラメータ

• mode (str) – Extrapolator to instantiate. Can be one of: - 『window』 - 『poly』 - 『diff_model』 - 『pca』 - 『l1』

• kwargs – arguments to be passed to the constructor of an extrapolator

戻り値の型

Extrapolator

戻り値

A newly created extrapolator instance.

例外

AquaError – if specified mode is unknown.