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

Class PseudoInverseCosine<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.PseudoInverseCosine<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 PseudoInverseCosine<U>
extends GlobalMatrixBasedRecommender<U>
Implementation of the pseudo inverse cosine algorithm for contact recommendation. This algorithm first computes the pseudo inverse of the Laplacian matrix (obtaining, for each user, a vector representation). Then, it takes the cosine similarity (which is computed as the (u,v) coordinate of the matrix, divided by the square root of the product of the (u,u) and (v,v) coordinates).
References:
  1. F. Fouss, A. Pirotte, J-M. Renders, M. Saerens. Random-walk computatin of similarities between nodes of a graph with application to collaborative recommendation. IEEE TKDE 19(3), pp. 355-369 (2007)

  • Field Summary

    Fields 
    Modifier and Type Field Description
    private EdgeOrientation orient
    The orientation for the Laplacian 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
    PseudoInverseCosine​(FastGraph<U> graph)
    Constructor.
    PseudoInverseCosine​(FastGraph<U> graph, 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