qiskit.chemistry.algorithms.pes_samplers.PCAExtrapolator¶
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class
PCAExtrapolator(extrapolator=None, kernel=None, window=2)[source]¶ 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.
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__init__(extrapolator=None, kernel=None, window=2)[source]¶ 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.
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extrapolate(points, param_dict)[source]¶ 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 pointthe value is a list of the variational parameters. (and) –
- Return type
Dict[float,List[float]]- Returns
Dictionary of variational parameters for extrapolated point(s).
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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.