org.grouplens.lenskit.basic

Class AbstractGlobalItemScorer

java.lang.Object

org.grouplens.lenskit.basic.AbstractGlobalItemScorer

All Implemented Interfaces:

GlobalItemScorer

Direct Known Subclasses:

ItemItemGlobalScorer

public abstract class AbstractGlobalItemScorer
extends Object
implements GlobalItemScorer

Base class to make global item scorers easier to implement. Delegates single=item score methods to collection-based ones,

Constructor Summary

Constructors

Constructor and Description
AbstractGlobalItemScorer()

Method Summary

Modifier and Type	Method and Description
MutableSparseVector	globalScore(Collection<Long> queryItems, Collection<Long> items) Score a collection of items based on a collection of items(a shopping basket).
double	globalScore(Collection<Long> queryItems, long item) Score a single item based on a collection of items(a shopping basket).

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.GlobalItemScorer

globalScore

Constructor Detail

AbstractGlobalItemScorer

public AbstractGlobalItemScorer()

Method Detail

globalScore

public double globalScore(@Nonnull
                          Collection<Long> queryItems,
                          long item)

Score a single item based on a collection of items(a shopping basket).

Delegate to globalScore(Collection, Collection).

Specified by:

globalScore in interface GlobalItemScorer

Parameters:

queryItems - The objective items ID used as the query

item - The item ID to score.

Returns:

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

globalScore

@Nonnull
public MutableSparseVector globalScore(@Nonnull
                                                Collection<Long> queryItems,
                                                @Nonnull
                                                Collection<Long> items)

Description copied from interface: GlobalItemScorer

Score a collection of items based on a collection of items(a shopping basket).

Specified by:

globalScore in interface GlobalItemScorer

Parameters:

queryItems - The objective items ID used as the query

items - The list of items to score.

Returns:

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