org.lenskit.bias

Class BiasItemScorer

java.lang.Object

org.lenskit.basic.AbstractItemScorer

org.lenskit.bias.BiasItemScorer

All Implemented Interfaces:

ItemScorer

public class BiasItemScorer
extends AbstractItemScorer

Score items using a user-item bias model. This scorer is good as a baseline scorer for many situations.

Constructor Summary

Constructors

Constructor and Description
BiasItemScorer(BiasModel bias) Construct a new scorer.

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.

Methods inherited from class java.lang.Object

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

Constructor Detail

BiasItemScorer

@Inject
public BiasItemScorer(BiasModel bias)

Construct a new scorer.

Parameters:

bias - The bias model to use.

Method Detail

score

public Result score(long user,
                    long item)

Description copied from class: AbstractItemScorer

Score a single item.

This implementation delegates to ItemScorer.scoreWithDetails(long, Collection).

Specified by:

score in interface ItemScorer

Overrides:

score in class AbstractItemScorer

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

Description copied from class: AbstractItemScorer

Score a collection of items.

This implementation delegates to ItemScorer.scoreWithDetails(long, Collection).

Specified by:

score in interface ItemScorer

Overrides:

score in class AbstractItemScorer

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

Description copied from interface: ItemScorer

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.