org.grouplens.lenskit.knn.item

Class ItemItemScorer

java.lang.Object

org.grouplens.lenskit.basic.AbstractItemScorer

org.grouplens.lenskit.knn.item.ItemItemScorer

All Implemented Interfaces:

ItemScorer

public class ItemItemScorer
extends AbstractItemScorer
implements ItemScorer

Score items using an item-item CF model. User ratings are not supplied as default preferences.

Field Summary

Fields

Modifier and Type	Field and Description
protected ItemScoreAlgorithm	algorithm
protected ItemItemModel	model
static Symbol	NEIGHBORHOOD_SIZE_SYMBOL
protected UserVectorNormalizer	normalizer
protected NeighborhoodScorer	scorer
protected UserHistorySummarizer	summarizer

Constructor Summary

Constructors

Constructor and Description
ItemItemScorer(UserEventDAO dao, ItemItemModel m, UserHistorySummarizer sum, NeighborhoodScorer scorer, ItemScoreAlgorithm algo, UserVectorNormalizer norm) Construct a new item-item scorer.

Method Summary

Modifier and Type	Method and Description
UserVectorNormalizer	getNormalizer()
void	score(long user, MutableSparseVector scores) Score items by computing predicted ratings.

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

score, score

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.grouplens.lenskit.ItemScorer

score, score

Field Detail

NEIGHBORHOOD_SIZE_SYMBOL

public static final Symbol NEIGHBORHOOD_SIZE_SYMBOL

model

protected final ItemItemModel model

normalizer

@Nonnull
protected final UserVectorNormalizer normalizer

summarizer

protected final UserHistorySummarizer summarizer

scorer

@Nonnull
protected final NeighborhoodScorer scorer

algorithm

@Nonnull
protected final ItemScoreAlgorithm algorithm

Constructor Detail

ItemItemScorer

@Inject
public ItemItemScorer(UserEventDAO dao,
                              ItemItemModel m,
                              UserHistorySummarizer sum,
                              NeighborhoodScorer scorer,
                              ItemScoreAlgorithm algo,
                              UserVectorNormalizer norm)

Construct a new item-item scorer.

Parameters:

dao - The DAO.

m - The model

sum - The history summarizer.

scorer - The neighborhood scorer.

algo - The item scoring algorithm. It converts neighborhoods to scores.

Method Detail

getNormalizer

@Nonnull
public UserVectorNormalizer getNormalizer()

score

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

Score items by computing predicted ratings.

Specified by:

score in interface ItemScorer

Parameters:

user - The user ID.

scores - The score vector.

See Also:

ItemScoreAlgorithm.scoreItems(ItemItemModel, SparseVector, MutableSparseVector, NeighborhoodScorer)