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

Class PageRankHittingTime<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.standalone.randomwalk.AbstractHittingTime<U>

es.uam.eps.ir.relison.links.recommendation.algorithms.standalone.randomwalk.PageRankHittingTime<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 PageRankHittingTime<U>
extends AbstractHittingTime<U>

Implementation of the Hitting time (using the not-personalized PageRank transition matrix)

Field Summary

Fields

Modifier and Type	Field	Description
private double[][]	matrix	The hitting time matrix.
private double	r	Teleport probability.

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
PageRankHittingTime(FastGraph<U> graph, double r)	Constructor.
PageRankHittingTime(FastGraph<U> graph, MatrixLibrary library, double r)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected cern.colt.matrix.DoubleMatrix2D	getCOLTTransitionMatrix(int uidx)	Obtains the transition matrix, for its use with the COLT library.
protected org.jblas.DoubleMatrix	getJBLASTransitionMatrix(int uidx)	Obtains the transition matrix, for its use with the JBLAS library.
double[][]	getMatrix(int uidx)	Obtains the matrix that provides the ratings given the target user.
protected no.uib.cipr.matrix.DenseMatrix	getMTJTransitionMatrix(int uidx)	Obtains the transition matrix, for its use with the MTJ library.

Methods inherited from class es.uam.eps.ir.relison.links.recommendation.algorithms.standalone.randomwalk.AbstractHittingTime

getCOLTMatrix, getJBLASMatrix, getMTJMatrix

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

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

matrix

private double[][] matrix

The hitting time matrix.

r

private final double r

Teleport probability.

Constructor Details

PageRankHittingTime

public PageRankHittingTime(FastGraph<U> graph, double r)

Constructor.

Parameters:

graph - a fast graph representing the social network.

r - teleport probability.

PageRankHittingTime

public PageRankHittingTime(FastGraph<U> graph, MatrixLibrary library, double r)

Constructor.

Parameters:

graph - a fast graph representing the social network.

library - the matrix library to use.

r - teleport probability.

Method Details

getJBLASTransitionMatrix

protected org.jblas.DoubleMatrix getJBLASTransitionMatrix(int uidx)

Description copied from class: AbstractHittingTime

Obtains the transition matrix, for its use with the JBLAS library.

Specified by:

getJBLASTransitionMatrix in class AbstractHittingTime<U>

Parameters:

uidx - the target user of the recommendation.

Returns:

a JBLAS matrix containing the transitions.

getCOLTTransitionMatrix

protected cern.colt.matrix.DoubleMatrix2D getCOLTTransitionMatrix(int uidx)

Description copied from class: AbstractHittingTime

Obtains the transition matrix, for its use with the COLT library.

Specified by:

getCOLTTransitionMatrix in class AbstractHittingTime<U>

Parameters:

uidx - the target user of the recommendation.

Returns:

a COLT matrix containing the transitions.

getMTJTransitionMatrix

protected no.uib.cipr.matrix.DenseMatrix getMTJTransitionMatrix(int uidx)

Description copied from class: AbstractHittingTime

Obtains the transition matrix, for its use with the MTJ library.

Specified by:

getMTJTransitionMatrix in class AbstractHittingTime<U>

Parameters:

uidx - the target user of the recommendation.

Returns:

a MTJ matrix containing the transitions.

getMatrix

public double[][] getMatrix(int uidx)

Description copied from class: MatrixBasedRecommender

Obtains the matrix that provides the ratings given the target user.

Overrides:

getMatrix in class MatrixBasedRecommender<U>

Parameters:

uidx - the target user.

Returns:

the matrix containing the item scores in the uidx row.