qiskit.chemistry.algorithms.pes_samplers.PCAExtrapolator
class PCAExtrapolator(extrapolator=None, kernel=None, window=2)
A wrapper extrapolator which reduces the points’ dimensionality with PCA, performs extrapolation in the transformed pca space, and inverse transforms the results before returning. A user specifies the kernel within how the PCA transformation should be done.
Constructor.
Parameters
- extrapolator (
Union[PolynomialExtrapolator,DifferentialExtrapolator,None]) – ‘internal’ extrapolator that performs extrapolation on variational parameters based on data window. - kernel (
Optional[str]) – Kernel (from sklearn) that specifies how dimensionality reduction should be done for PCA. Default value is None, and switches the extrapolation to standard PCA. - window (
int) – Number of previous points to use for extrapolation.
Raises
AquaError – if kernel is not defined in sklearn module.
__init__
__init__(extrapolator=None, kernel=None, window=2)
Constructor.
Parameters
- extrapolator (
Union[PolynomialExtrapolator,DifferentialExtrapolator,None]) – ‘internal’ extrapolator that performs extrapolation on variational parameters based on data window. - kernel (
Optional[str]) – Kernel (from sklearn) that specifies how dimensionality reduction should be done for PCA. Default value is None, and switches the extrapolation to standard PCA. - window (
int) – Number of previous points to use for extrapolation.
Raises
AquaError – if kernel is not defined in sklearn module.
Methods
__init__([extrapolator, kernel, 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
extrapolate(points, param_dict)
Extrapolate at specified point of interest given a set of variational parameters. This method transforms the parameters in PCA space before performing the internal extrapolation. The parameters are transformed back to regular space after extrapolation.
Parameters
- 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 - the value is a list of the variational parameters. (and) –
Return type
Dict[float, List[float]]
Returns
Dictionary of variational parameters for extrapolated point(s).
factory
static factory(mode, **kwargs)
Factory method for constructing extrapolators.
Parameters
- 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
Return type
Extrapolator
Returns
A newly created extrapolator instance.
Raises
AquaError – if specified mode is unknown.