Class WindowFeatureGenerator

java.lang.Object

opennlp.tools.util.featuregen.WindowFeatureGenerator

All Implemented Interfaces:

opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

public class WindowFeatureGenerator
extends Object
implements opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

Generates previous (left-sided) and next (right-sided) features for a given AdaptiveFeatureGenerator. The window size can be specified.

Features:

• Current token is always included unchanged,
• Previous tokens are prefixed with p distance,
• Next tokens are prefix with n distance.

See Also:

• AdaptiveFeatureGenerator

Field Summary

Fields

Modifier and Type	Field	Description
static final String	NEXT_PREFIX
static final String	PREV_PREFIX

Constructor Summary

Constructors

Constructor	Description
WindowFeatureGenerator(int prevWindowSize, int nextWindowSize, opennlp.tools.util.featuregen.AdaptiveFeatureGenerator... generators)	Initializes a WindowFeatureGenerator with the given parameters.
WindowFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator generator)	Initializes a WindowFeatureGenerator.
WindowFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator... generators)	Initializes a WindowFeatureGenerator.
WindowFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator generator, int prevWindowSize, int nextWindowSize)	Initializes a WindowFeatureGenerator with the given parameters.

Method Summary

Modifier and Type	Method	Description
void	clearAdaptiveData()
void	createFeatures(List<String> features, String[] tokens, int index, String[] preds)
String	toString()
void	updateAdaptiveData(String[] tokens, String[] outcomes)

Methods inherited from class Object

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

Field Details

PREV_PREFIX

public static final String PREV_PREFIX

See Also:

• Constant Field Values

NEXT_PREFIX

public static final String NEXT_PREFIX

See Also:

• Constant Field Values

Constructor Details

WindowFeatureGenerator

public WindowFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator generator,
 int prevWindowSize,
 int nextWindowSize)

Initializes a WindowFeatureGenerator with the given parameters.

Parameters:

generator - The AdaptiveFeatureGenerator to apply to the window.

prevWindowSize - Size of the window to the left of the current token.

nextWindowSize - Size of the window to the right of the current token.

WindowFeatureGenerator

public WindowFeatureGenerator(int prevWindowSize,
 int nextWindowSize,
 opennlp.tools.util.featuregen.AdaptiveFeatureGenerator... generators)

Initializes a WindowFeatureGenerator with the given parameters.

Parameters:

prevWindowSize - Size of the window to the left of the current token.

nextWindowSize - Size of the window to the right of the current token.

generators - One or more AdaptiveFeatureGenerator to apply to the window.

WindowFeatureGenerator

public WindowFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator generator)

Initializes a WindowFeatureGenerator. The previous and next window size is 5.

Parameters:

generator - The AdaptiveFeatureGenerator to apply to the window.

WindowFeatureGenerator

public WindowFeatureGenerator(opennlp.tools.util.featuregen.AdaptiveFeatureGenerator... generators)

Initializes a WindowFeatureGenerator. The previous and next window size is 5.

Parameters:

generators - One or more AdaptiveFeatureGenerator to apply to the window.

Method Details

createFeatures

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

Specified by:

createFeatures in interface opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

updateAdaptiveData

public void updateAdaptiveData(String[] tokens,
 String[] outcomes)

Specified by:

updateAdaptiveData in interface opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

clearAdaptiveData

public void clearAdaptiveData()

Specified by:

clearAdaptiveData in interface opennlp.tools.util.featuregen.AdaptiveFeatureGenerator

toString

public String toString()

Overrides:

toString in class Object