Package opennlp.tools.util.featuregen

Class CharacterNgramFeatureGenerator

java.lang.Object

opennlp.tools.util.featuregen.CharacterNgramFeatureGenerator

All Implemented Interfaces:

AdaptiveFeatureGenerator

public class CharacterNgramFeatureGenerator
extends Object
implements AdaptiveFeatureGenerator

The CharacterNgramFeatureGenerator uses character ngrams to generate features about each token.

See Also:

• AdaptiveFeatureGenerator

Constructor Summary

Constructors

Constructor	Description
CharacterNgramFeatureGenerator()	Initializes a CharacterNgramFeatureGenerator with default values for ngrams.
CharacterNgramFeatureGenerator(int minLength, int maxLength)	Initializes a CharacterNgramFeatureGenerator with the specified parameters.

Method Summary

Modifier and Type	Method	Description
void	createFeatures(List<String> features, String[] tokens, int index, String[] preds)	Adds the appropriate features for the token at the specified index with the specified array of previousOutcomes to the specified list of features.

Methods inherited from class java.lang.Object

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

Methods inherited from interface opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

clearAdaptiveData, updateAdaptiveData

Constructor Details

CharacterNgramFeatureGenerator

public CharacterNgramFeatureGenerator(int minLength,
 int maxLength)

Initializes a CharacterNgramFeatureGenerator with the specified parameters.

Parameters:

minLength - The minimum length to use. Must not be negative.

maxLength - The maximum length to use. Must not be negative.

CharacterNgramFeatureGenerator

public CharacterNgramFeatureGenerator()

Initializes a CharacterNgramFeatureGenerator with default values for ngrams. The minimal length is set to 2 and maximum length to a value of 5.

Method Details

createFeatures

public void createFeatures(List<String> features,
 String[] tokens,
 int index,
 String[] preds)

Description copied from interface: AdaptiveFeatureGenerator

Adds the appropriate features for the token at the specified index with the specified array of previousOutcomes to the specified list of features.

Specified by:

createFeatures in interface AdaptiveFeatureGenerator

Parameters:

features - The list of features to be added to.

tokens - The tokens of the sentence or other text unit being processed.

index - The index of the token which is currently being processed.

preds - The outcomes for the tokens prior to the specified index.