Package es.uam.eps.ir.relison.links.recommendation.algorithms.standalone.pathbased

Class LocalPathIndex<U>

java.lang.Object

es.uam.eps.ir.ranksys.rec.AbstractRecommender<U,I>

es.uam.eps.ir.ranksys.rec.fast.AbstractFastRecommender<U,I>

es.uam.eps.ir.ranksys.rec.fast.FastRankingRecommender<U,U>

es.uam.eps.ir.relison.links.recommendation.UserFastRankingRecommender<U>

es.uam.eps.ir.relison.links.recommendation.algorithms.MatrixBasedRecommender<U>

es.uam.eps.ir.relison.links.recommendation.algorithms.GlobalMatrixBasedRecommender<U>

es.uam.eps.ir.relison.links.recommendation.algorithms.standalone.pathbased.LocalPathIndex<U>

Type Parameters:

U - type of the users

All Implemented Interfaces:

es.uam.eps.ir.ranksys.core.index.ItemIndex<U>, es.uam.eps.ir.ranksys.core.index.UserIndex<U>, es.uam.eps.ir.ranksys.fast.index.FastItemIndex<U>, es.uam.eps.ir.ranksys.fast.index.FastUserIndex<U>, es.uam.eps.ir.ranksys.rec.fast.FastRecommender<U,U>, es.uam.eps.ir.ranksys.rec.Recommender<U,U>

public class LocalPathIndex<U>
extends GlobalMatrixBasedRecommender<U>

Local path index recommender. It takes all paths of distances between 2 and k between the target and candidate users, and weights them, so shortest paths are more important.
References:

1. L. Lü, C. Jin, T. Zhou. Similarity Index Based on Local Paths for Link Prediction of Complex Networks. Physical Review E 80(4): 046122 (2009)
2. L. Lü, T. Zhou. Link Prediction in Complex Networks: A survey. Physica A 390(6), 1150-1170 (2011)

Field Summary

Fields

Modifier and Type	Field	Description
private double	beta	Dampening factor.
private double	k	The maximum distance between users.
private EdgeOrientation	orient	The orientation for the adjacency matrix.

Fields inherited from class es.uam.eps.ir.relison.links.recommendation.algorithms.GlobalMatrixBasedRecommender

matrix

Fields inherited from class es.uam.eps.ir.relison.links.recommendation.algorithms.MatrixBasedRecommender

library

Fields inherited from class es.uam.eps.ir.relison.links.recommendation.UserFastRankingRecommender

graph

Fields inherited from class es.uam.eps.ir.ranksys.rec.fast.AbstractFastRecommender

iIndex, uIndex

Constructor Summary

Constructors

Constructor	Description
LocalPathIndex(FastGraph<U> graph, double beta, int k)	Constructor.
LocalPathIndex(FastGraph<U> graph, double beta, int k, EdgeOrientation orient)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected double[][]	getCOLTMatrix()	Obtains the matrix using the COLT library.
protected double[][]	getJBLASMatrix()	Obtains the matrix using the JBLAS library.
protected double[][]	getMTJMatrix()	Obtains the matrix using the MTJ library.

Methods inherited from class es.uam.eps.ir.relison.links.recommendation.algorithms.GlobalMatrixBasedRecommender

getCOLTMatrix, getJBLASMatrix, getMatrix, getMTJMatrix

Methods inherited from class es.uam.eps.ir.relison.links.recommendation.algorithms.MatrixBasedRecommender

getMatrix, getScoresMap

Methods inherited from class es.uam.eps.ir.relison.links.recommendation.UserFastRankingRecommender

getFreq, getFreq, getGraph

Methods inherited from class es.uam.eps.ir.ranksys.rec.fast.FastRankingRecommender

getRecommendation

Methods inherited from class es.uam.eps.ir.ranksys.rec.fast.AbstractFastRecommender

getRecommendation, getRecommendation, getRecommendation, getRecommendation, getRecommendation, getRecommendation, getRecommendation, iidx2item, item2iidx, numItems, numUsers, uidx2user, user2uidx

Methods inherited from class es.uam.eps.ir.ranksys.rec.AbstractRecommender

getRecommendation, getRecommendation

Methods inherited from class java.lang.Object

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

Methods inherited from interface es.uam.eps.ir.ranksys.fast.index.FastItemIndex

containsItem, getAllIidx, getAllItems, iidx2item, iidx2item, item2iidx, item2iidx

Methods inherited from interface es.uam.eps.ir.ranksys.fast.index.FastUserIndex

containsUser, getAllUidx, getAllUsers, uidx2user, uidx2user, user2uidx, user2uidx

Methods inherited from interface es.uam.eps.ir.ranksys.rec.Recommender

getRecommendation, getRecommendation

Field Details

beta

private final double beta

Dampening factor.

k

private final double k

The maximum distance between users.

orient

private final EdgeOrientation orient

The orientation for the adjacency matrix.

Constructor Details

LocalPathIndex

public LocalPathIndex(FastGraph<U> graph, double beta, int k)

Constructor. Takes the outgoing orientation by default.

Parameters:

graph - a fast graph representing the social network.

beta - the dampening factor.

k - the maximum distance between the target and candidate users (k greater or equal than 2)

LocalPathIndex

public LocalPathIndex(FastGraph<U> graph, double beta, int k, EdgeOrientation orient)

Constructor.

Parameters:

graph - a fast graph representing the social network.

beta - the dampening factor.

k - the maximum distance between the target and candidate users (k greater or equal than 2)

orient - the orientation for selecting the adjacency matrix.

Method Details

getJBLASMatrix

protected double[][] getJBLASMatrix()

Description copied from class: GlobalMatrixBasedRecommender

Obtains the matrix using the JBLAS library.

Specified by:

getJBLASMatrix in class GlobalMatrixBasedRecommender<U>

Returns:

the matrix.

getCOLTMatrix

protected double[][] getCOLTMatrix()

Description copied from class: GlobalMatrixBasedRecommender

Obtains the matrix using the COLT library.

Specified by:

getCOLTMatrix in class GlobalMatrixBasedRecommender<U>

Returns:

the matrix.

getMTJMatrix

protected double[][] getMTJMatrix()

Description copied from class: GlobalMatrixBasedRecommender

Obtains the matrix using the MTJ library.

Specified by:

getMTJMatrix in class GlobalMatrixBasedRecommender<U>

Returns:

the matrix.