spectrochempy.ParetoScaleTransformer

class ParetoScaleTransformer(dim='y')[source]

Pareto scaling transformer.

Learns the mean and standard deviation along a dimension during fit() and applies \((x - \bar{x}) / \sqrt{s}\) during transform().

Parameters

dim (str or int, optional, default:’y’) – Dimension along which the statistics are computed.

mean_[source]

Learned mean.

Type

ndarray

std_[source]

Learned standard deviation.

Type

ndarray

Examples

>>> scaler = scp.ParetoScaleTransformer(dim="y")
>>> scaler.fit(train)
>>> test_scaled = scaler.transform(test)

See also

pareto_scale

Procedural Pareto scaling function.

Methods Summary

fit(dataset)

Learn parameters from dataset.

fit_transform(dataset)

Fit to dataset, then transform it.

get_params([deep])

Get the constructor parameters of this transformer.

inverse_transform(dataset)

Reverse the learned transformation on dataset.

set_params(**params)

Set constructor parameters on this transformer.

transform(dataset)

Apply the learned transformation to dataset.

Methods Documentation

fit(dataset)[source]

Learn parameters from dataset.

Parameters

dataset (NDDataset) – Training data.

Returns

self – The fitted instance.

fit_transform(dataset)[source]

Fit to dataset, then transform it.

Equivalent to self.fit(dataset).transform(dataset) but avoids an intermediate copy when possible.

Parameters

dataset (NDDataset) – Training data.

Returns

NDDataset – Transformed dataset.

get_params(deep=True)[source]

Get the constructor parameters of this transformer.

Parameters

deep (bool, optional, default:True) – Ignored. Present for compatibility with scikit-learn conventions.

Returns

dict – Mapping of parameter name -> current value.

Examples

>>> scaler = scp.AutoscaleTransformer(dim="y")
>>> scaler.get_params()
{'dim': 'y'}
inverse_transform(dataset)[source]

Reverse the learned transformation on dataset.

Parameters

dataset (NDDataset) – Data to invert.

Returns

NDDataset – Dataset in the original space.

Raises

SpectroChemPyError – If fit() has not been called first.

set_params(**params)[source]

Set constructor parameters on this transformer.

Returns self so that calls can be chained.

Parameters

**params – Parameter names and values to update.

Returns

self

Raises

SpectroChemPyError – If a parameter name does not correspond to a constructor argument.

Examples

>>> scaler = scp.AutoscaleTransformer(dim="y")
>>> scaler.set_params(dim="x")
AutoscaleTransformer(dim='x')
transform(dataset)[source]

Apply the learned transformation to dataset.

Parameters

dataset (NDDataset) – Data to transform.

Returns

NDDataset – Transformed dataset.

Raises

SpectroChemPyError – If fit() has not been called first.

Examples using spectrochempy.ParetoScaleTransformer