edu.ucla.sspace.wordsi

Class WordOccrrenceDependencyContextGenerator

java.lang.Object

edu.ucla.sspace.wordsi.WordOccrrenceDependencyContextGenerator

All Implemented Interfaces:

DependencyContextGenerator

public class WordOccrrenceDependencyContextGenerator
extends Object
implements DependencyContextGenerator

A DependencyContextGenerator that forms co-occurrence context vectors from words that are reachable via a valid DependencyPath from a focus term.

Author:

Keith Stevens

Constructor Summary

Constructors

Constructor and Description
WordOccrrenceDependencyContextGenerator(DependencyPathBasisMapping basisMapping, DependencyPathWeight weighter, DependencyPathAcceptor acceptor, int pathLength) Creates a new WordOccrrenceDependencyContextGenerator

Method Summary

Methods

Modifier and Type	Method and Description
SparseDoubleVector	generateContext(DependencyTreeNode[] tree, int focusIndex) Returns a SparseDoubleVector that represents the context composed of the set of prevWords before the focus word and the set of nextWords after the focus word.
int	getVectorLength() Returns the maximum number of dimensions used to represent any given context.
void	setReadOnly(boolean readOnly) Sets the read only mode of the ContextGenerator.

Methods inherited from class java.lang.Object

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

Constructor Detail

WordOccrrenceDependencyContextGenerator

public WordOccrrenceDependencyContextGenerator(DependencyPathBasisMapping basisMapping,
                                       DependencyPathWeight weighter,
                                       DependencyPathAcceptor acceptor,
                                       int pathLength)

Creates a new WordOccrrenceDependencyContextGenerator

Parameters:

basisMapping - A mapping from word forms to their feature indices

weighter - A weight function applied to each DependencyPath

acceptor - An acceptor that rejects invalid DependencyPath

pathLength - The maximum length for a valid DependencyPath

Method Detail

generateContext

public SparseDoubleVector generateContext(DependencyTreeNode[] tree,
                                 int focusIndex)

Returns a SparseDoubleVector that represents the context composed of the set of prevWords before the focus word and the set of nextWords after the focus word. Since sparse vectors are returned, if a second order vector is generated, it is recommended that the vector also be sparsed or have very few dimensions.

Specified by:

generateContext in interface DependencyContextGenerator

getVectorLength

public int getVectorLength()

Returns the maximum number of dimensions used to represent any given context.

Specified by:

getVectorLength in interface DependencyContextGenerator

setReadOnly

public void setReadOnly(boolean readOnly)

Sets the read only mode of the ContextGenerator. When set to read only, it prevents any new features from being generated.

Specified by:

setReadOnly in interface DependencyContextGenerator