org.grouplens.lenskit.basic

Class SimpleRatingPredictor

java.lang.Object

org.grouplens.lenskit.basic.AbstractRatingPredictor

org.grouplens.lenskit.basic.SimpleRatingPredictor

All Implemented Interfaces:

RatingPredictor

public final class SimpleRatingPredictor
extends AbstractRatingPredictor

Basic RatingPredictor backed by an ItemScorer. The scores are clamped to the preference domain but otherwise unmodified.

If a baseline predictor is provided, then it is used to supply predictions that the item scorer could not.

This class has a provider SimpleRatingPredictor.Provider that is the default provider for RatingPredictor.

Since:

1.1

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SimpleRatingPredictor.Provider An intelligent provider for simple rating predictors.

Field Summary

Fields

Modifier and Type	Field and Description
static TypedSymbol<ScoreSource>	PREDICTION_SOURCE_SYMBOL

Constructor Summary

Constructors

Constructor and Description
SimpleRatingPredictor(ItemScorer scorer, ItemScorer baseline, PreferenceDomain domain)

Method Summary

Modifier and Type	Method and Description
ItemScorer	getBaselineScorer() Get the baseline predictor.
PreferenceDomain	getPreferenceDomain() Get the preference domain.
ItemScorer	getScorer() Get the backing scorer.
void	predict(long user, MutableSparseVector scores) Predict for items in a vector.

Methods inherited from class org.grouplens.lenskit.basic.AbstractRatingPredictor

predict, predict

Methods inherited from class java.lang.Object

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

Field Detail

PREDICTION_SOURCE_SYMBOL

public static final TypedSymbol<ScoreSource> PREDICTION_SOURCE_SYMBOL

Constructor Detail

SimpleRatingPredictor

@Inject
public SimpleRatingPredictor(@PrimaryScorer
                                     ItemScorer scorer,
                                     @Nullable @BaselineScorer
                                     ItemScorer baseline,
                                     @Nullable
                                     PreferenceDomain domain)

Method Detail

getScorer

public ItemScorer getScorer()

Get the backing scorer.

Returns:

The item scorer.

getPreferenceDomain

@Nullable
public PreferenceDomain getPreferenceDomain()

Get the preference domain.

Returns:

The preference domain

getBaselineScorer

@Nullable
public ItemScorer getBaselineScorer()

Get the baseline predictor.

Returns:

The baseline predictor, or null if no baseline is configured.

predict

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

Description copied from interface: RatingPredictor

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

Parameters:

user - The user ID.

scores - The prediction output vector. Its key domain is the items to score.