org.lenskit.api

Interface ItemScorer

All Known Implementing Classes:

AbstractItemScorer, BiasItemScorer, ConstantItemScorer, FallbackItemScorer, GlobalMeanRatingItemScorer, ItemItemScorer, ItemMeanRatingItemScorer, LeastSquaresItemScorer, PopularityRankItemScorer, PrecomputedItemScorer, RatingPredictorItemScorer, SimpleCachingItemScorer, SlopeOneItemScorer, UserMeanItemScorer, UserUserItemScorer, WeightedSlopeOneItemScorer

public interface ItemScorer

Score items for users. These scores can be predicted ratings, relevance scores, purchase probabilities, or any other real-valued score which can be assigned to an item for a particular user.

Compatibility

Public

Method Summary

Modifier and Type	Method and Description
java.util.Map<java.lang.Long,java.lang.Double>	score(long user, java.util.Collection<java.lang.Long> items) Score a collection of items.
Result	score(long user, long item) Score a single item.
ResultMap	scoreWithDetails(long user, java.util.Collection<java.lang.Long> items) Score a collection of items and potentially return more details on the scores.

Method Detail

score

Result score(long user,
             long item)

Score a single item.

Parameters:

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

item - The item ID to score.

Returns:

The score, or null if no score can be generated.

score

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

Score a collection of items.

Parameters:

user - The user ID for whom to generate scores.

items - The item to score.

Returns:

The scores for the items. This result set may not contain all requested items.

scoreWithDetails

@Nonnull
ResultMap scoreWithDetails(long user,
                                    @Nonnull
                                    java.util.Collection<java.lang.Long> items)

Score a collection of items and potentially return more details on the scores.

Parameters:

user - The user ID for whom to generate scores.

items - The item to score.

Returns:

The scores for the items. This result set may not contain all requested items. Implementations that support additional details will return a subclass of ResultMap that provides access to those details.