DatabaseScaler

Module for Scaler plugin

class DatabaseScaler(scaler, mode, target)

Bases: Plugin

The plugin to rescale the database of the reduced order model. It uses a user defined scaler, which has to have implemented the fit, transform and inverse_trasform methods (i.e. sklearn interface), to rescale the parameters and/or the snapshots. It can be applied at the full order (mode=’full’), at the reduced one (mode=’reduced’) or both of them (mode=’both’).

Parameters:

• scaler (obj) – a generic object which has to have implemented the fit, transform and inverse_trasform methods (i.e. sklearn interface).

• mode ({'full', 'reduced'}) – define if the rescaling has to be applied at the full order (‘full’) or at the reduced one (‘reduced’).

• params ({'parameters', 'snapshots'}) – define if the rescaling has to be applied to the parameters or to the snapshots.

Example:

>>> from ezyrb import ReducedOrderModel as ROM
>>> from ezyrb import POD, RBF, Database
>>> from ezyrb.plugin import DatabaseScaler
>>> from sklearn.preprocessing import StandardScaler
>>> pod = POD(rank=10)
>>> rbf = RBF()
>>> db = Database(params, snapshots)
>>> scaler = DatabaseScaler(StandardScaler(), 'full', 'snapshots')
>>> rom = ROM(db, pod, rbf, plugins=[scaler])
>>> rom.fit()

Initialize the DatabaseScaler plugin.

Parameters:

• scaler – Scaler object with fit, transform, and inverse_transform methods.

• mode (str) – ‘full’ or ‘reduced’ - where to apply the scaling.

• target (str) – ‘parameters’ or ‘snapshots’ - what to scale.

_abc_impl = <_abc._abc_data object>

_select_matrix(db)

Helper function to select the proper matrix to rescale.

Parameters:

db (Database) – The database object.

Returns:

The selected matrix (parameters or snapshots).

fom_postprocessing(rom)

fom_preprocessing(rom)

property mode

Get the type of scaling. See class documentation for more info.

rtype: str

rom_postprocessing(rom)

rom_preprocessing(rom)

Apply scaling to the reduced database before ROM processing.

Parameters:

rom (ReducedOrderModel) – The ROM instance.

property target

Get the type of scaling. See class documentation for more info.

rtype: str