smile.feature

Class Scaler

java.lang.Object

smile.feature.FeatureTransform

smile.feature.Scaler

Direct Known Subclasses:

WinsorScaler

public class Scaler
extends FeatureTransform

Scales all numeric variables into the range [0, 1]. If the dataset has outliers, normalization will certainly scale the "normal" data to a very small interval. In this case, the Winsorization procedure should be applied: values greater than the specified upper limit are replaced with the upper limit, and those below the lower limit are replace with the lower limit. Often, the specified range is indicate in terms of percentiles of the original distribution (like the 5th and 95th percentile).

Constructor Summary

Constructors

Constructor and Description
Scaler() Constructor.
Scaler(boolean copy) Constructor.

Method Summary

Modifier and Type	Method and Description
void	learn(Attribute[] attributes, double[][] data) Learns transformation parameters from a dataset.
java.lang.String	toString()
double[]	transform(double[] x) Transform a feature vector.

Methods inherited from class smile.feature.FeatureTransform

learn, transform

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Scaler

public Scaler()

Constructor. Inplace transformation.

Scaler

public Scaler(boolean copy)

Constructor.

Parameters:

copy - If false, try to avoid a copy and do inplace scaling instead.

Method Detail

learn

public void learn(Attribute[] attributes,
                  double[][] data)

Description copied from class: FeatureTransform

Learns transformation parameters from a dataset.

Specified by:

learn in class FeatureTransform

Parameters:

attributes - The variable attributes. Of which, numeric variables will be standardized.

data - The training data to learn scaling parameters. The data will not be modified.

transform

public double[] transform(double[] x)

Description copied from class: FeatureTransform

Transform a feature vector.

Specified by:

transform in class FeatureTransform

Parameters:

x - a feature vector.

Returns:

the transformed feature value.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object