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

Class CentroidCosineSimilarity<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.standalone.bipartite.BipartiteRecommender<U>
es.uam.eps.ir.relison.links.recommendation.algorithms.standalone.bipartite.CentroidCosineSimilarity<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 CentroidCosineSimilarity<U>
extends BipartiteRecommender<U>
Recommender. Builds a centroid for each user in the network, using the vectors of the followed users. The score is then computed as the cosine similarity of those centroids.

  • Field Summary

    Fields 
    Modifier and Type Field Description
    private java.util.Map<U,​cern.colt.matrix.DoubleMatrix1D> authVectors
    Vectorial representation of the authorities.
    private java.util.Map<java.lang.Long,​java.lang.Integer> hubIdx
    Identifiers of the hubs.
    private java.util.Map<U,​java.lang.Double> normVectors
    Norms of the vectors.

    Fields inherited from class es.uam.eps.ir.relison.links.recommendation.algorithms.standalone.bipartite.BipartiteRecommender

    authorities, bipartiteGraph, hubs, mode

    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
    CentroidCosineSimilarity​(FastGraph<U> graph)
    Constructor

  • Method Summary

    Modifier and Type Method Description
    private double computeCentroid​(long hub, cern.colt.matrix.DoubleMatrix1D centroid)
    Computes a centroid for a hub
    private double computeVector​(long auth, cern.colt.matrix.DoubleMatrix1D vector)
    Computes the vector for an authority.
    it.unimi.dsi.fastutil.ints.Int2DoubleMap getScoresMap​(int i)  

    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

    • authVectors

      private final java.util.Map<U,​cern.colt.matrix.DoubleMatrix1D> authVectors
      Vectorial representation of the authorities.

    • normVectors

      private final java.util.Map<U,​java.lang.Double> normVectors
      Norms of the vectors.

    • hubIdx

      private final java.util.Map<java.lang.Long,​java.lang.Integer> hubIdx
      Identifiers of the hubs.

  • Constructor Details

  • Method Details

    • getScoresMap

      public it.unimi.dsi.fastutil.ints.Int2DoubleMap getScoresMap​(int i)
      Specified by:
      getScoresMap in class es.uam.eps.ir.ranksys.rec.fast.FastRankingRecommender<U,​U>

    • computeVector

      private double computeVector​(long auth, cern.colt.matrix.DoubleMatrix1D vector)
      Computes the vector for an authority.
      Parameters:
      auth - The identifier of the authority.
      vector - The vector.
      Returns:
      The norm of the vector (L2 norm)

    • computeCentroid

      private double computeCentroid​(long hub, cern.colt.matrix.DoubleMatrix1D centroid)
      Computes a centroid for a hub
      Parameters:
      hub - The identifier of the hub.
      centroid - The vector.
      Returns:
      The norm of the vector (L2 norm).