es.uam.eps.ir.ranksys.nn.item

Class ItemNeighborhoodRecommender<U,I>

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,I>

es.uam.eps.ir.ranksys.nn.item.ItemNeighborhoodRecommender<U,I>

Type Parameters:

U - type of the users

I - type of the items

All Implemented Interfaces:

ItemIndex<I>, UserIndex<U>, FastItemIndex<I>, FastUserIndex<U>, FastRecommender<U,I>, Recommender<U,I>

public class ItemNeighborhoodRecommender<U,I>
extends FastRankingRecommender<U,I>

Item-based nearest neighbors recommender. F. Aiolli. Efficient Top-N Recommendation for Very Large Scale Binary Rated Datasets. RecSys 2013. P. Cremonesi, Y. Koren, and R. Turrin. Performance of recommender algorithms on top-N recommendation tasks. RecSys 2010. B. Sarwar, G. Karypis, J. Konstan, and J. Riedl. Item-based collaborative filtering recommendation algorithms. WWW 2001.

Author:

Saúl Vargas (saul.vargas@uam.es)

Field Summary

Fields

Modifier and Type	Field and Description
protected FastPreferenceData<U,I>	data Preference data.
protected ItemNeighborhood<I>	neighborhood Item neighborhoods.
protected int	q Exponent of the similarity.

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

iIndex, uIndex

Constructor Summary

Constructors

Constructor and Description
ItemNeighborhoodRecommender(FastPreferenceData<U,I> data, ItemNeighborhood<I> neighborhood, int q) Constructor.

Method Summary

Modifier and Type	Method and Description
it.unimi.dsi.fastutil.ints.Int2DoubleMap	getScoresMap(int uidx) Returns a map of item-score pairs.

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.rec.Recommender

getRecommendation, getRecommendation

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.fast.index.FastItemIndex

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

Field Detail

data

protected final FastPreferenceData<U,I> data

Preference data.

neighborhood

protected final ItemNeighborhood<I> neighborhood

Item neighborhoods.

q

protected final int q

Exponent of the similarity.

Constructor Detail

ItemNeighborhoodRecommender

public ItemNeighborhoodRecommender(FastPreferenceData<U,I> data,
                                   ItemNeighborhood<I> neighborhood,
                                   int q)

Constructor.

Parameters:

data - preference data

neighborhood - item neighborhood

q - exponent of the similarity

Method Detail

getScoresMap

public it.unimi.dsi.fastutil.ints.Int2DoubleMap getScoresMap(int uidx)

Returns a map of item-score pairs.

Specified by:

getScoresMap in class FastRankingRecommender<U,I>

Parameters:

uidx - index of the user whose scores are predicted

Returns:

a map of item-score pairs