es.uam.eps.ir.ranksys.nn.user.neighborhood

Class UserNeighborhood<U>

java.lang.Object

es.uam.eps.ir.ranksys.nn.user.neighborhood.UserNeighborhood<U>

Type Parameters:

U - type of the users

All Implemented Interfaces:

UserIndex<U>, FastUserIndex<U>, Neighborhood

Direct Known Subclasses:

CachedUserNeighborhood, InvertedUserNeighborhood, ThresholdUserNeighborhood, TopKUserNeighborhood

public abstract class UserNeighborhood<U>
extends Object
implements Neighborhood, FastUserIndex<U>

User neighborhood. Wraps a generic neighborhood and a fast user index.

Author:

Saúl Vargas (saul.vargas@uam.es)

Field Summary

Fields

Modifier and Type	Field and Description
protected Neighborhood	neighborhood Generic fast neighborhood.
protected FastUserIndex<U>	uIndex Fast user index.

Constructor Summary

Constructors

Constructor and Description
UserNeighborhood(FastUserIndex<U> uIndex, Neighborhood neighborhood) Constructor

Method Summary

Modifier and Type	Method and Description
Stream<Tuple2id>	getNeighbors(int idx) Returns the neighborhood of a user/index.
Stream<Tuple2od<U>>	getNeighbors(U u) Returns a stream of user neighbors
int	numUsers() Counts the number of indexed users.
U	uidx2user(int uidx) Returns the user represented with the index.
int	user2uidx(U u) Returns the index assigned to the user.

Methods inherited from class java.lang.Object

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

Methods inherited from interface es.uam.eps.ir.ranksys.fast.index.FastUserIndex

containsUser, getAllUidx, getAllUsers, uidx2user, uidx2user, user2uidx, user2uidx

Field Detail

uIndex

protected final FastUserIndex<U> uIndex

Fast user index.

neighborhood

protected final Neighborhood neighborhood

Generic fast neighborhood.

Constructor Detail

UserNeighborhood

public UserNeighborhood(FastUserIndex<U> uIndex,
                        Neighborhood neighborhood)

Constructor

Parameters:

uIndex - fast user index

neighborhood - generic fast neighborhood

Method Detail

numUsers

public int numUsers()

Description copied from interface: UserIndex

Counts the number of indexed users.

Specified by:

numUsers in interface UserIndex<U>

Returns:

the total number of users

user2uidx

public int user2uidx(U u)

Description copied from interface: FastUserIndex

Returns the index assigned to the user.

Specified by:

user2uidx in interface FastUserIndex<U>

Parameters:

u - user

Returns:

the index of the user, or -1 if the user does not exist

uidx2user

public U uidx2user(int uidx)

Description copied from interface: FastUserIndex

Returns the user represented with the index.

Specified by:

uidx2user in interface FastUserIndex<U>

Parameters:

uidx - user index

Returns:

the user whose index is uidx

getNeighbors

public Stream<Tuple2id> getNeighbors(int idx)

Returns the neighborhood of a user/index.

Specified by:

getNeighbors in interface Neighborhood

Parameters:

idx - user/index whose neighborhood is calculated

Returns:

stream of user/item-similarity pairs.

getNeighbors

public Stream<Tuple2od<U>> getNeighbors(U u)

Returns a stream of user neighbors

Parameters:

u - user whose neighborhood is returned

Returns:

a stream of user-score pairs