org.apache.ignite.ml.preprocessing.encoding.onehotencoder

Class OneHotEncoderPreprocessor<K,V>

java.lang.Object

org.apache.ignite.ml.preprocessing.encoding.EncoderPreprocessor<K,V>

org.apache.ignite.ml.preprocessing.encoding.onehotencoder.OneHotEncoderPreprocessor<K,V>

Type Parameters:

K - Type of a key in upstream data.

V - Type of a value in upstream data.

All Implemented Interfaces:

Serializable, BiFunction<K,V,Vector>, IgniteBiFunction<K,V,Vector>

public class OneHotEncoderPreprocessor<K,V>
extends EncoderPreprocessor<K,V>

Preprocessing function that makes one-hot encoding. One-hot encoding maps a categorical feature, represented as a label index (Double or String value), to a binary vector with at most a single one-value indicating the presence of a specific feature value from among the set of all feature values. This preprocessor can transform multiple columns which indices are handled during training process. Each one-hot encoded binary vector adds its cells to the end of the current feature vector.

See Also:

This prerpocessor always creates separate column for the NULL values. NOTE: the index value associated with NULL will located in binary vector according the frequency of NULL values., Serialized Form

Field Summary

Fields inherited from class org.apache.ignite.ml.preprocessing.encoding.EncoderPreprocessor

basePreprocessor, encodingValues, handledIndices, KEY_FOR_NULL_VALUES

Constructor Summary

Constructors

Constructor and Description
OneHotEncoderPreprocessor(Map<String,Integer>[] encodingValues, IgniteBiFunction<K,V,Object[]> basePreprocessor, Set<Integer> handledIndices) Constructs a new instance of One Hot Encoder preprocessor.

Method Summary

Modifier and Type	Method and Description
Vector	apply(K k, V v) Applies this preprocessor.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.ignite.ml.math.functions.IgniteBiFunction

andThen

Methods inherited from interface java.util.function.BiFunction

andThen

Constructor Detail

OneHotEncoderPreprocessor

public OneHotEncoderPreprocessor(Map<String,Integer>[] encodingValues,
                                 IgniteBiFunction<K,V,Object[]> basePreprocessor,
                                 Set<Integer> handledIndices)

Constructs a new instance of One Hot Encoder preprocessor.

Parameters:

basePreprocessor - Base preprocessor.

handledIndices - Handled indices.

Method Detail

apply

public Vector apply(K k,
                    V v)

Applies this preprocessor.

Parameters:

k - Key.

v - Value.

Returns:

Preprocessed row.