ivory.ffg.feature

Class UnorderedWindowSequentialDependenceFeature

java.lang.Object

ivory.ffg.feature.UnorderedWindowSequentialDependenceFeature

All Implemented Interfaces:

Feature

public class UnorderedWindowSequentialDependenceFeature
extends Object
implements Feature

Implementation of a phrase feature (unordered-window, sequential-dependence model)

Author:

Nima Asadi

Constructor Summary

Constructors

Constructor and Description
UnorderedWindowSequentialDependenceFeature(int window)

Method Summary

Methods

Modifier and Type	Method and Description
float	computeScoreWithMiniIndexes(int[][] positions, int[] query, int dl, GlobalStats stats) Computes the feature value using a (mini-)indexed document.
float	computeScoreWithSlidingWindow(int[] document, int[] query, int[] hashedQuery, GlobalStats stats) Computes the feature value using a sliding window given a document, query and a scoring function
static int[]	countTerms(int[][] positions, int window)
static int[]	countTerms(int[] document, int[] query, int window)
void	initialize(ScoringFunction scoringFunction) Initializes this feature.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

UnorderedWindowSequentialDependenceFeature

public UnorderedWindowSequentialDependenceFeature(int window)

Parameters:

window - Window size

Method Detail

computeScoreWithMiniIndexes

public float computeScoreWithMiniIndexes(int[][] positions,
                                int[] query,
                                int dl,
                                GlobalStats stats)

Description copied from interface: Feature

Computes the feature value using a (mini-)indexed document.

Specified by:

computeScoreWithMiniIndexes in interface Feature

Parameters:

positions - Positions of each term in the query

query - Original query terms

dl - Document length

stats - Global statistics

Returns:

Feature value

computeScoreWithSlidingWindow

public float computeScoreWithSlidingWindow(int[] document,
                                  int[] query,
                                  int[] hashedQuery,
                                  GlobalStats stats)

Description copied from interface: Feature

Computes the feature value using a sliding window given a document, query and a scoring function

Specified by:

computeScoreWithSlidingWindow in interface Feature

Parameters:

document - Flat array representation of a document vector.

query - Original query terms (used to retrieve global statistics)

hashedQuery - Hashed query terms (the same as query for techniques that don't use hashing)

stats - Global statistics

Returns:

Feature value

countTerms

public static int[] countTerms(int[][] positions,
               int window)

countTerms

public static int[] countTerms(int[] document,
               int[] query,
               int window)

initialize

public void initialize(ScoringFunction scoringFunction)

Description copied from interface: Feature

Initializes this feature.

Specified by:

initialize in interface Feature

Parameters:

scoringFunction - scoring function

toString

public String toString()

Overrides:

toString in class Object