Package org.tribuo.classification.sequence.viterbi

Class DefaultFeatureExtractor

java.lang.Object

org.tribuo.classification.sequence.viterbi.DefaultFeatureExtractor

All Implemented Interfaces:

com.oracle.labs.mlrg.olcut.config.Configurable, com.oracle.labs.mlrg.olcut.provenance.Provenancable<com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance>, Serializable, LabelFeatureExtractor

public class DefaultFeatureExtractor
extends Object
implements LabelFeatureExtractor

A label feature extractor that produces several kinds of label-based features.

The options are: the most recent output, the least recent output, recent bigrams, recent trigrams, recent 4-grams.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
DefaultFeatureExtractor()	Constructs a default feature extractor for bigrams and trigrams using the past 3 outcomes.
DefaultFeatureExtractor(int mostRecentOutcome, int leastRecentOutcome, boolean useBigram, boolean useTrigram, boolean use4gram)	Constructs a default feature extractor using the supplied parameters.

Method Summary

Modifier and Type	Method	Description
List<Feature>	extractFeatures(List<Label> previousOutcomes, double value)	Generates features based on the previously produced labels.
com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance	getProvenance()
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.labs.mlrg.olcut.config.Configurable

postConfig

Constructor Details

DefaultFeatureExtractor

public DefaultFeatureExtractor()

Constructs a default feature extractor for bigrams and trigrams using the past 3 outcomes.

DefaultFeatureExtractor

public DefaultFeatureExtractor(int mostRecentOutcome,
 int leastRecentOutcome,
 boolean useBigram,
 boolean useTrigram,
 boolean use4gram)

Constructs a default feature extractor using the supplied parameters.

Parameters:

mostRecentOutcome - The most recent outcome to include as a feature.

leastRecentOutcome - The least recent outcome to include as a feature.

useBigram - Use bigrams of the outcomes.

useTrigram - Use trigrams of the outcomes.

use4gram - Use 4-grams of the outcomes.

Method Details

toString

public String toString()

Overrides:

toString in class Object

extractFeatures

public List<Feature> extractFeatures(List<Label> previousOutcomes,
 double value)

Description copied from interface: LabelFeatureExtractor

Generates features based on the previously produced labels.

Specified by:

extractFeatures in interface LabelFeatureExtractor

Parameters:

previousOutcomes - The previous step's labels.

value - The value to give to the features.

Returns:

Features.

getProvenance

public com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance getProvenance()

Specified by:

getProvenance in interface com.oracle.labs.mlrg.olcut.provenance.Provenancable<com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance>