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

Class CentroidCBRecommender<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.contentbased.CentroidCBRecommender<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 CentroidCBRecommender<U>
extends UserFastRankingRecommender<U>
Content-based recommendation algorithm, based on a tf-idf scheme. Each piece of content published by a single user is considered as taken as a single content. Then, using some of these contents, a centroid using the tf-idf weights is computed for each user. Finally, the recommendation score of a link is just the cosine similarity between the vectors of two separate users.

  • Field Summary

    Fields 
    Modifier and Type Field Description
    private java.util.Map<U,​java.util.Map<java.lang.String,​java.lang.Double>> centroids
    The centroids of the users.
    private java.util.Map<java.lang.String,​java.util.Map<U,​java.lang.Double>> invCentroids
    Inverse index for the centroids.
    private java.util.Map<U,​java.lang.Double> modules
    Modules of the centroids.

    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
    CentroidCBRecommender​(FastGraph<U> graph, WrapperIndividualForwardContentIndex<?,​U> index)
    Constructor.
    CentroidCBRecommender​(FastGraph<U> graph, WrapperIndividualForwardContentIndex<?,​U> index, EdgeOrientation orient)
    Constructor.

  • Method Summary

    Modifier and Type Method Description
    private void createTerm​(java.lang.String term)
    Add a term to the inverse centroid.
    it.unimi.dsi.fastutil.ints.Int2DoubleMap getScoresMap​(int uIdx)  

    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

    • centroids

      private final java.util.Map<U,​java.util.Map<java.lang.String,​java.lang.Double>> centroids
      The centroids of the users.

    • invCentroids

      private final java.util.Map<java.lang.String,​java.util.Map<U,​java.lang.Double>> invCentroids
      Inverse index for the centroids.

    • modules

      private final java.util.Map<U,​java.lang.Double> modules
      Modules of the centroids.

  • Constructor Details

    • CentroidCBRecommender

      public CentroidCBRecommender​(FastGraph<U> graph, WrapperIndividualForwardContentIndex<?,​U> index)
      Constructor. This variant just takes the information pieces published by each user to generate his/her centroid.
      Parameters:
      graph - The training graph.
      index - Content index that contains information about users.

    • CentroidCBRecommender

      public CentroidCBRecommender​(FastGraph<U> graph, WrapperIndividualForwardContentIndex<?,​U> index, EdgeOrientation orient)
      Constructor. This variant takes the contents published by the neighbors of a user to generate the centroids.
      Parameters:
      graph - the training graph.
      index - content index that contains information about users.
      orient - the orientation for selecting the neighbors.

  • Method Details

    • createTerm

      private void createTerm​(java.lang.String term)
      Add a term to the inverse centroid.
      Parameters:
      term - the term.

    • getScoresMap

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