org.lenskit.basic

Class SimpleRatingPredictor

java.lang.Object

org.lenskit.basic.SimpleRatingPredictor

All Implemented Interfaces:

RatingPredictor

public class SimpleRatingPredictor
extends Object
implements RatingPredictor

Basic rating predictor that uses scores, clamped to valid rating values if appropriate. It returns results of type RescoredResult.

The default item scorer used by the rating predictor is provided by FallbackItemScorer.DynamicProvider, so it will default to falling back to the baseline scorer if one is present.

Constructor Summary

Constructors

Constructor and Description
SimpleRatingPredictor(ItemScorer s, PreferenceDomain dom) Create a new simple rating predictor.

Method Summary

Modifier and Type	Method and Description
ItemScorer	getItemScorer()
PreferenceDomain	getPreferenceDomain()
Map<Long,Double>	predict(long user, Collection<Long> items) Predict the user’s preference for a collection of items.
RescoredResult	predict(long user, long item) Predict a user’s rating for a single item.
ResultMap	predictWithDetails(long user, Collection<Long> items) Predict the user’s preference for a collection of items, potentially with additional details.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleRatingPredictor

@Inject
public SimpleRatingPredictor(@Nonnull @PredictionScorer
                                      ItemScorer s,
                                      @Nullable
                                      PreferenceDomain dom)

Create a new simple rating predictor.

Parameters:

s - The scorer.

dom - The preference domain.

Method Detail

getItemScorer

@Nonnull
public ItemScorer getItemScorer()

getPreferenceDomain

@Nullable
public PreferenceDomain getPreferenceDomain()

predict

public RescoredResult predict(long user,
                              long item)

Description copied from interface: RatingPredictor

Predict a user’s rating for a single item.

Specified by:

predict in interface RatingPredictor

Parameters:

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

item - The item ID whose rating is to be predicted.

Returns:

The predicted preference, or Double.NaN if no preference can be predicted.

predict

@Nonnull
public Map<Long,Double> predict(long user,
                                          @Nonnull
                                          Collection<Long> items)

Description copied from interface: RatingPredictor

Predict the user’s preference for a collection of items.

Specified by:

predict in interface RatingPredictor

Parameters:

user - The user ID for whom to generate predicts.

items - The items to predict for.

Returns:

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

predictWithDetails

@Nonnull
public ResultMap predictWithDetails(long user,
                                              @Nonnull
                                              Collection<Long> items)

Description copied from interface: RatingPredictor

Predict the user’s preference for a collection of items, potentially with additional details.

Specified by:

predictWithDetails in interface RatingPredictor

Parameters:

user - The user ID for whom to generate predicts.

items - The items to predict for.

Returns:

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