org.grouplens.lenskit.knn.item.model

Class ItemwiseBuildContextProvider

java.lang.Object

org.grouplens.lenskit.knn.item.model.ItemwiseBuildContextProvider

All Implemented Interfaces:

javax.inject.Provider<ItemItemBuildContext>

public class ItemwiseBuildContextProvider
extends Object
implements javax.inject.Provider<ItemItemBuildContext>

Builder for ItemItemBuildContext that normalizes per-item, not per-user. More efficient when using e.g. item-based normalization. Right now it only works for rating data.

Constructor Summary

Constructors

Constructor and Description
ItemwiseBuildContextProvider(ItemEventDAO edao, ItemDAO idao, ItemVectorNormalizer norm) Construct a new build context provider.

Method Summary

Modifier and Type	Method and Description
ItemItemBuildContext	get() Constructs and returns a new ItemItemBuildContext.

Methods inherited from class java.lang.Object

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

Constructor Detail

ItemwiseBuildContextProvider

@Inject
public ItemwiseBuildContextProvider(ItemEventDAO edao,
                                            ItemDAO idao,
                                            ItemVectorNormalizer norm)

Construct a new build context provider.

Parameters:

edao - The item-event DAO.

idao - The item DAO.

norm - The item vector normalizer. This is applied to item rating vectors. You should take care to use a compatible normalizer for the item scorer (e.g. if this uses a MeanCenteringVectorNormalizer, then you should use ItemMeanRatingItemScorer for the user vector normalization in the scorer).

Method Detail

get

public ItemItemBuildContext get()

Constructs and returns a new ItemItemBuildContext.

Specified by:

get in interface javax.inject.Provider<ItemItemBuildContext>

Returns:

a new ItemItemBuildContext.