es.uam.eps.ir.ranksys.rec.fast.basic

Class RandomRecommender<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.basic.RandomRecommender<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 RandomRecommender<U,I>
extends AbstractFastRecommender<U,I>

Random recommender. It provides non-personalized recommendations without by extracting a sequence of a shuffled list of the items.

Author:

Saúl Vargas (saul.vargas@uam.es)

Field Summary

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

iIndex, uIndex

Constructor Summary

Constructors

Constructor and Description
RandomRecommender(FastUserIndex<U> uIndex, FastItemIndex<I> iIndex) Constructor.

Method Summary

Modifier and Type	Method and Description
FastRecommendation	getRecommendation(int uidx, int maxLength, IntPredicate filter) Filter recommendation.
FastRecommendation	getRecommendation(int uidx, IntStream candidates) Candidates ranking.
Recommendation<U,I>	getRecommendation(U u, Stream<I> candidates) Candidates ranking.

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

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

Constructor Detail

RandomRecommender

public RandomRecommender(FastUserIndex<U> uIndex,
                         FastItemIndex<I> iIndex)

Constructor.

Parameters:

uIndex - fast user index

iIndex - fast item index

Method Detail

getRecommendation

public FastRecommendation getRecommendation(int uidx,
                                            int maxLength,
                                            IntPredicate filter)

Description copied from interface: FastRecommender

Filter recommendation. Recommends only the items that pass the filter up to a maximum list size.

Specified by:

getRecommendation in interface FastRecommender<U,I>

Specified by:

getRecommendation in class AbstractFastRecommender<U,I>

Parameters:

uidx - index of the user to be issued a recommendation

maxLength - maximum length of recommendation

filter - (fast) filter to decide which items might be recommended

Returns:

a (fast) recommendation list

getRecommendation

public Recommendation<U,I> getRecommendation(U u,
                                             Stream<I> candidates)

Description copied from interface: Recommender

Candidates ranking. Create a list that may contain only the items in the candidates set.

Specified by:

getRecommendation in interface Recommender<U,I>

Overrides:

getRecommendation in class AbstractFastRecommender<U,I>

Parameters:

u - user to be issued a recommendation

candidates - candidate items to be included in the recommendation

Returns:

a recommendation list

getRecommendation

public FastRecommendation getRecommendation(int uidx,
                                            IntStream candidates)

Description copied from interface: FastRecommender

Candidates ranking. Create a list that may contain only the items in the candidates set.

Specified by:

getRecommendation in interface FastRecommender<U,I>

Overrides:

getRecommendation in class AbstractFastRecommender<U,I>

Parameters:

uidx - item of the user to be issued a recommendation

candidates - candidate items to be included in the recommendation

Returns:

a recommendation list