org.apache.mahout.cf.taste.impl.recommender

Class AbstractCandidateItemsStrategy

java.lang.Object

org.apache.mahout.cf.taste.impl.recommender.AbstractCandidateItemsStrategy

All Implemented Interfaces:

Refreshable, CandidateItemsStrategy, MostSimilarItemsCandidateItemsStrategy

Direct Known Subclasses:

AllSimilarItemsCandidateItemsStrategy, AllUnknownItemsCandidateItemsStrategy, PreferredItemsNeighborhoodCandidateItemsStrategy, SamplingCandidateItemsStrategy

public abstract class AbstractCandidateItemsStrategy
extends Object
implements CandidateItemsStrategy, MostSimilarItemsCandidateItemsStrategy

Abstract base implementation for retrieving candidate items to recommend

Constructor Summary

Constructors

Constructor and Description
AbstractCandidateItemsStrategy()

Method Summary

Modifier and Type	Method and Description
protected FastIDSet	doGetCandidateItems(long[] preferredItemIDs, DataModel dataModel)
protected abstract FastIDSet	doGetCandidateItems(long[] preferredItemIDs, DataModel dataModel, boolean includeKnownItems)
FastIDSet	getCandidateItems(long[] itemIDs, DataModel dataModel)
FastIDSet	getCandidateItems(long userID, PreferenceArray preferencesFromUser, DataModel dataModel, boolean includeKnownItems)
void	refresh(Collection<Refreshable> alreadyRefreshed) Triggers "refresh" -- whatever that means -- of the implementation.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractCandidateItemsStrategy

public AbstractCandidateItemsStrategy()

Method Detail

doGetCandidateItems

protected FastIDSet doGetCandidateItems(long[] preferredItemIDs,
                                        DataModel dataModel)
                                 throws TasteException

Throws:

TasteException

getCandidateItems

public FastIDSet getCandidateItems(long userID,
                                   PreferenceArray preferencesFromUser,
                                   DataModel dataModel,
                                   boolean includeKnownItems)
                            throws TasteException

Specified by:

getCandidateItems in interface CandidateItemsStrategy

Returns:

IDs of all items that could be recommended to the user

Throws:

TasteException

getCandidateItems

public FastIDSet getCandidateItems(long[] itemIDs,
                                   DataModel dataModel)
                            throws TasteException

Specified by:

getCandidateItems in interface MostSimilarItemsCandidateItemsStrategy

Throws:

TasteException

doGetCandidateItems

protected abstract FastIDSet doGetCandidateItems(long[] preferredItemIDs,
                                                 DataModel dataModel,
                                                 boolean includeKnownItems)
                                          throws TasteException

Throws:

TasteException

refresh

public void refresh(Collection<Refreshable> alreadyRefreshed)

Description copied from interface: Refreshable

Triggers "refresh" -- whatever that means -- of the implementation. The general contract is that any Refreshable should always leave itself in a consistent, operational state, and that the refresh atomically updates internal state from old to new.

Specified by:

refresh in interface Refreshable

Parameters:

alreadyRefreshed - Refreshables that are known to have already been refreshed as a result of an initial call to a {#refresh(Collection)} method on some object. This ensure that objects in a refresh dependency graph aren't refreshed twice needlessly.