org.grouplens.lenskit.scored

Class ScoredIds

java.lang.Object

org.grouplens.lenskit.scored.ScoredIds

public final class ScoredIds
extends Object

Utility classes for working with scored IDs.

Since:

1.1

Compatibility

Public

Method Summary

Modifier and Type	Method and Description
static Ordering<ScoredId>	channelOrder(Symbol chan) An ordering (comparator) that compares IDs by channel.
static <T extends Comparable<? super T>> Ordering<ScoredId>	channelOrder(TypedSymbol<T> chan) An ordering (comparator) that compares IDs by typed channel.
static <T> Ordering<ScoredId>	channelOrder(TypedSymbol<T> chan, Comparator<? super T> order) An ordering (comparator) that compares IDs by typed channel.
static FastCollection<ScoredId>	collectionFromVector(SparseVector vector) View a vector as a FastCollection of ScoredId objects.
static ScoredIdBuilder	copyBuilder(ScoredId id) Create a new builder initialized to copy the specified scored ID.
static ScoredId	create(long id, double score) Create a scored id with no channels.
static Function<ScoredId,Long>	idFunction() A Function that extracts the ID from a scored ID.
static Ordering<ScoredId>	idOrder() An ordering (comparator) that compares IDs by score.
static ScoredIdBuilder	newBuilder() Create a new builder.
static ScoredIdListBuilder	newListBuilder() Create a new list builder.
static ScoredIdListBuilder	newListBuilder(int cap) Create a new list builder.
static Ordering<ScoredId>	scoreOrder() An ordering (comparator) that compares IDs by score.

Methods inherited from class java.lang.Object

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

Method Detail

copyBuilder

public static ScoredIdBuilder copyBuilder(ScoredId id)

Create a new builder initialized to copy the specified scored ID.

Parameters:

id - The scored ID to copy.

Returns:

A new builder that will copy the ID.

newBuilder

public static ScoredIdBuilder newBuilder()

Create a new builder.

Returns:

A new scored ID builder.

newListBuilder

public static ScoredIdListBuilder newListBuilder()

Create a new list builder.

Returns:

A new scored ID list builder.

newListBuilder

public static ScoredIdListBuilder newListBuilder(int cap)

Create a new list builder.

Parameters:

cap - The initial capacity to reserve.

Returns:

A new scored ID list builder.

create

public static ScoredId create(long id,
                              double score)

Create a scored id with no channels.

Parameters:

id - The ID.

score - The score.

Returns:

An ID.

idFunction

public static Function<ScoredId,Long> idFunction()

A Function that extracts the ID from a scored ID.

Returns:

A function returning the ID from any scored ID.

idOrder

public static Ordering<ScoredId> idOrder()

An ordering (comparator) that compares IDs by score.

Returns:

An ordering over ScoredIds by score.

scoreOrder

public static Ordering<ScoredId> scoreOrder()

An ordering (comparator) that compares IDs by score.

Returns:

An ordering over ScoredIds by score.

channelOrder

public static Ordering<ScoredId> channelOrder(Symbol chan)

An ordering (comparator) that compares IDs by channel. Missing channels are less than present channels.

Parameters:

chan - The channel to sort by.

Returns:

An ordering over scored IDs by channel.

channelOrder

public static <T extends Comparable<? super T>> Ordering<ScoredId> channelOrder(TypedSymbol<T> chan)

An ordering (comparator) that compares IDs by typed channel. Null values are sorted first. This method calls channelOrder(TypedSymbol, Comparator) with a comparator of Ordering.natural().nullsFirst().

Parameters:

chan - The channel to sort by.

Returns:

A comparator over scored IDs.

See Also:

channelOrder(TypedSymbol, Comparator)

channelOrder

public static <T> Ordering<ScoredId> channelOrder(TypedSymbol<T> chan,
                                                  Comparator<? super T> order)

An ordering (comparator) that compares IDs by typed channel. Missing channels and null Ids are both treated as having null channel values, so their ordering is controlled by the order's null treatment.

Parameters:

chan - The channel to sort by.

order - The ordering to use.

Returns:

A comparator over scored IDs.

collectionFromVector

public static FastCollection<ScoredId> collectionFromVector(SparseVector vector)

View a vector as a FastCollection of ScoredId objects.

Parameters:

vector - The vector to view as a collection of ScoredIds

Returns:

A fast collection containing this vector's keys and values as ScoredId objects.