org.ranksys.fm

Class PreferenceFM<U,I>

java.lang.Object

org.ranksys.fm.PreferenceFM<U,I>

Type Parameters:

U - type of users

I - type of items

All Implemented Interfaces:

ItemIndex<I>, UserIndex<U>, FastItemIndex<I>, FastUserIndex<U>

public class PreferenceFM<U,I>
extends Object
implements FastUserIndex<U>, FastItemIndex<I>

Wraps a factorisation machine to work with RankSys user-preference pairs.

Author:

Saúl Vargas (Saul@VargasSandoval.es)

Constructor Summary

Constructors

Constructor and Description
PreferenceFM(FastUserIndex<U> users, FastItemIndex<I> items, org.ranksys.javafm.FM fm) Constructor with default converter to IdxPref.
PreferenceFM(FastUserIndex<U> users, FastItemIndex<I> items, org.ranksys.javafm.FM fm, Function<IdPref<I>,IdxPref> uPrefFun) Constructor with custom default converter to IdxPref.

Method Summary

Modifier and Type	Method and Description
boolean	containsItem(I i) Checks whether the index contains an item.
boolean	containsUser(U u) Checks whether the index contains a user.
Stream<I>	getAllItems() Retrieves a stream of the indexed items.
Stream<U>	getAllUsers() Retrieves a stream of the indexed users.
org.ranksys.javafm.FM	getFM() Returns the enclosed factorisation machine.
I	iidx2item(int i) Returns the item represented with the index.
int	item2iidx(I i) Returns the index assigned to the item.
int	numItems() Counts the number of indexed items.
int	numUsers() Counts the number of indexed users.
double	predict(int uidx, IdxPref pref) Predicts the preference by a user to an item preference (fast version).
double	predict(U u, IdPref<I> pref) Predicts the preference by a user to an item preference.
U	uidx2user(int i) 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

getAllUidx, uidx2user, uidx2user, user2uidx, user2uidx

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

getAllIidx, iidx2item, iidx2item, item2iidx, item2iidx

Constructor Detail

PreferenceFM

public PreferenceFM(FastUserIndex<U> users,
                    FastItemIndex<I> items,
                    org.ranksys.javafm.FM fm)

Constructor with default converter to IdxPref.

Parameters:

users - user index

items - item index

fm - factorisation machine

PreferenceFM

public PreferenceFM(FastUserIndex<U> users,
                    FastItemIndex<I> items,
                    org.ranksys.javafm.FM fm,
                    Function<IdPref<I>,IdxPref> uPrefFun)

Constructor with custom default converter to IdxPref.

Parameters:

users - user index

items - item index

fm - factorisation machine

uPrefFun - converter to IdxPref

Method Detail

getFM

public org.ranksys.javafm.FM getFM()

Returns the enclosed factorisation machine.

Returns:

factorisation machine

predict

public double predict(U u,
                      IdPref<I> pref)

Predicts the preference by a user to an item preference.

Parameters:

u - user

pref - preference

Returns:

predicted score

predict

public double predict(int uidx,
                      IdxPref pref)

Predicts the preference by a user to an item preference (fast version).

Parameters:

uidx - user

pref - preference

Returns:

predicted score

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 i)

Description copied from interface: FastUserIndex

Returns the user represented with the index.

Specified by:

uidx2user in interface FastUserIndex<U>

Parameters:

i - user index

Returns:

the user whose index is uidx

containsUser

public boolean containsUser(U u)

Description copied from interface: UserIndex

Checks whether the index contains a user.

Specified by:

containsUser in interface UserIndex<U>

Specified by:

containsUser in interface FastUserIndex<U>

Parameters:

u - user

Returns:

true if the index contains the user, false otherwise

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

getAllUsers

public Stream<U> getAllUsers()

Description copied from interface: UserIndex

Retrieves a stream of the indexed users.

Specified by:

getAllUsers in interface UserIndex<U>

Specified by:

getAllUsers in interface FastUserIndex<U>

Returns:

a stream of all the users

item2iidx

public int item2iidx(I i)

Description copied from interface: FastItemIndex

Returns the index assigned to the item.

Specified by:

item2iidx in interface FastItemIndex<I>

Parameters:

i - item

Returns:

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

iidx2item

public I iidx2item(int i)

Description copied from interface: FastItemIndex

Returns the item represented with the index.

Specified by:

iidx2item in interface FastItemIndex<I>

Parameters:

i - item index

Returns:

the item whose index is iidx

containsItem

public boolean containsItem(I i)

Description copied from interface: ItemIndex

Checks whether the index contains an item.

Specified by:

containsItem in interface ItemIndex<I>

Specified by:

containsItem in interface FastItemIndex<I>

Parameters:

i - item

Returns:

true if the index contains the item, false otherwise

numItems

public int numItems()

Description copied from interface: ItemIndex

Counts the number of indexed items.

Specified by:

numItems in interface ItemIndex<I>

Returns:

the total number of item

getAllItems

public Stream<I> getAllItems()

Description copied from interface: ItemIndex

Retrieves a stream of the indexed items.

Specified by:

getAllItems in interface ItemIndex<I>

Specified by:

getAllItems in interface FastItemIndex<I>

Returns:

a stream of all the items