edu.illinois.cs.cogcomp.edison.features.factory

Class DependencyPathNgrams

java.lang.Object

edu.illinois.cs.cogcomp.edison.features.factory.DependencyPathNgrams

All Implemented Interfaces:

FeatureExtractor

public class DependencyPathNgrams
extends Object
implements FeatureExtractor

Given two tokens, this feature extractor extracts the following features:

• The path in the dependency tree from the first token of the first constituent to the first token of the second one.
• The length of the path

The dependency tree is read from the view name specified in the constructor. If possible, use the static objects for the Easy-first dependency tree (which uses ViewNames.DEPENDENCY) or the Stanford dependency tree (which uses ViewNames.DEPENDENCY_STANFORD)

Important note: To be able to specify the two constituents as input, the feature extractor assumes the following convention: The constituent that is specified as a parameter to the getFeatures function has an incoming relation from the first constituent. Furthermore, this incoming relation should be the only such relation.

This convention does not limit the expressivity in any way because the two constituents could be created on the spot before calling the feature extractor.

Author:

Vivek Srikumar

Field Summary

Fields

Modifier and Type	Field and Description
static DependencyPathNgrams	EASY_FIRST_BIGRAM
static DependencyPathNgrams	EASY_FIRST_UNIGRAM
static DependencyPathNgrams	STANFORD_BIGRAM
static DependencyPathNgrams	STANFORD_UNIGRAM

Constructor Summary

Constructors

Constructor and Description
DependencyPathNgrams(String dependencyViewName, int ngramSize) Extracting ngram features along the dependency path

Method Summary

Modifier and Type	Method and Description
Set<Feature>	getFeatures(Constituent c)
String	getName()

Methods inherited from class java.lang.Object

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

Field Detail

EASY_FIRST_UNIGRAM

public static DependencyPathNgrams EASY_FIRST_UNIGRAM

STANFORD_UNIGRAM

public static DependencyPathNgrams STANFORD_UNIGRAM

EASY_FIRST_BIGRAM

public static DependencyPathNgrams EASY_FIRST_BIGRAM

STANFORD_BIGRAM

public static DependencyPathNgrams STANFORD_BIGRAM

Constructor Detail

DependencyPathNgrams

public DependencyPathNgrams(String dependencyViewName,
                            int ngramSize)

Extracting ngram features along the dependency path

Method Detail

getFeatures

public Set<Feature> getFeatures(Constituent c)
                         throws EdisonException

Specified by:

getFeatures in interface FeatureExtractor

Throws:

EdisonException

getName

public String getName()

Specified by:

getName in interface FeatureExtractor