org.grouplens.lenskit.predict

Class RatingPredictorItemScorer

java.lang.Object

org.grouplens.lenskit.predict.RatingPredictorItemScorer

All Implemented Interfaces:

ItemScorer

public class RatingPredictorItemScorer
extends java.lang.Object
implements ItemScorer

Item scorer that uses rating predictions. Use this if you want to use the outputs of a sophisticated rating predictor somewhere that requires item scorers.

Since:

2.1

Constructor Summary

Constructors

Constructor and Description
RatingPredictorItemScorer(RatingPredictor pred)

Method Summary

Modifier and Type	Method and Description
SparseVector	score(long user, java.util.Collection<java.lang.Long> items) Score a collection of items.
double	score(long user, long item) Score a single item.
void	score(long user, MutableSparseVector scores) Score items in a vector.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RatingPredictorItemScorer

@Inject
public RatingPredictorItemScorer(RatingPredictor pred)

Method Detail

score

public double score(long user,
                    long item)

Description copied from interface: ItemScorer

Score a single item.

Specified by:

score in interface ItemScorer

Parameters:

user - The user ID for whom to generate a score.

item - The item ID to score.

Returns:

The score, or Double.NaN if no score can be generated.

score

@Nonnull
public SparseVector score(long user,
                                   @Nonnull
                                   java.util.Collection<java.lang.Long> items)

Description copied from interface: ItemScorer

Score a collection of items.

Specified by:

score in interface ItemScorer

Parameters:

user - The user ID for whom to generate scores.

items - The item to score.

Returns:

A mapping from item IDs to predicted preference. This mapping may not contain all requested items.

score

public void score(long user,
                  @Nonnull
                  MutableSparseVector scores)

Description copied from interface: ItemScorer

Score items in a vector. The key domain of the provided vector is the items to score, and the score method sets the values for each item to its score (or unsets it, if no score can be provided). The previous values are discarded.

Specified by:

score in interface ItemScorer

Parameters:

user - The user ID.

scores - The score vector.