es.uam.eps.ir.ranksys.fast.preference

Class TransposedPreferenceData<I,U>

java.lang.Object

es.uam.eps.ir.ranksys.fast.preference.TransposedPreferenceData<I,U>

Type Parameters:

I - type of the items

U - type of the users

All Implemented Interfaces:

ItemIndex<U>, UserIndex<I>, PreferenceData<I,U>, FastItemIndex<U>, FastUserIndex<I>, FastPreferenceData<I,U>, PointWisePreferenceData<I,U>, FastPointWisePreferenceData<I,U>

public class TransposedPreferenceData<I,U>
extends Object
implements FastPreferenceData<I,U>, FastPointWisePreferenceData<I,U>

Transposed preferences, where users and items change roles. This class is useful to simplify the implementation of many algorithms that work user or item-wise, such as similarities or matrix factorization.

Author:

Saúl Vargas (saul.vargas@uam.es)

Constructor Summary

Constructors

Constructor and Description
TransposedPreferenceData(FastPreferenceData<U,I> recommenderData) Constructor with default converters between IdxPref and IdPref.
TransposedPreferenceData(FastPreferenceData<U,I> recommenderData, org.jooq.lambda.function.Function2<U,IdPref<I>,IdPref<U>> idPrefFun, org.jooq.lambda.function.Function2<Integer,IdxPref,IdxPref> idxPrefFun) Constructor with custom converters between IdxPref and IdPref.

Method Summary

Modifier and Type	Method and Description
IntStream	getAllIidx() Gets all the indices of the items.
Stream<U>	getAllItems() Retrieves a stream of the indexed items.
IntStream	getAllUidx() Gets all the indices of the users.
Stream<I>	getAllUsers() Retrieves a stream of the indexed users.
Stream<? extends IdxPref>	getIidxPreferences(int iidx) Gets the preferences of an item.
it.unimi.dsi.fastutil.ints.IntIterator	getIidxUidxs(int iidx) Returns the user idxs of the preferences for an item.
it.unimi.dsi.fastutil.doubles.DoubleIterator	getIidxVs(int iidx) Returns the user values of the preferences for an item.
IntStream	getIidxWithPreferences() Returns a stream of item indexes for which users have preferences.
Stream<? extends IdPref<I>>	getItemPreferences(U i) Returns a stream of the preferences of the item
Stream<U>	getItemsWithPreferences() Returns a stream of the items with preferences
Optional<IdxPref>	getPreference(int uidx, int iidx) Get preference of a user for an item.
Optional<IdPref<U>>	getPreference(I u, U i) Get preference of a user for an item.
it.unimi.dsi.fastutil.ints.IntIterator	getUidxIidxs(int uidx) Returns the item idxs of the preferences of a user.
Stream<? extends IdxPref>	getUidxPreferences(int uidx) Gets the preferences of a user.
it.unimi.dsi.fastutil.doubles.DoubleIterator	getUidxVs(int uidx) Returns the item values of the preferences of a user.
IntStream	getUidxWithPreferences() Returns a stream of user indexes who have preferences for items.
Stream<? extends IdPref<U>>	getUserPreferences(I u) Returns a stream of the preferences of the user
Stream<I>	getUsersWithPreferences() Returns a stream of the users with preferences
U	iidx2item(int iidx) Returns the item represented with the index.
int	item2iidx(U i) Returns the index assigned to the item.
int	numItems() Counts the number of indexed items.
int	numItems(I u) Returns the number of items with preference for user u
int	numItems(int uidx) Returns the number of items for which the user has preference for.
int	numItemsWithPreferences() Returns the number of items with preferences.
int	numPreferences() Returns the total number of preferences
int	numUsers() Counts the number of indexed users.
int	numUsers(int iidx) Returns the number of users who have a preference for the item.
int	numUsers(U i) Returns the number of users with preference for item i
int	numUsersWithPreferences() Returns the number of users with preferences.
I	uidx2user(int uidx) Returns the user represented with the index.
boolean	useIteratorsPreferentially() Use methods returning IntIterator or DoubleIterator over streams of IdxPref?
int	user2uidx(I 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, uidx2user, uidx2user, user2uidx, user2uidx

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

containsItem, iidx2item, iidx2item, item2iidx, item2iidx

Constructor Detail

TransposedPreferenceData

public TransposedPreferenceData(FastPreferenceData<U,I> recommenderData)

Constructor with default converters between IdxPref and IdPref.

Parameters:

recommenderData - preference data to be transposed

TransposedPreferenceData

public TransposedPreferenceData(FastPreferenceData<U,I> recommenderData,
                                org.jooq.lambda.function.Function2<U,IdPref<I>,IdPref<U>> idPrefFun,
                                org.jooq.lambda.function.Function2<Integer,IdxPref,IdxPref> idxPrefFun)

Constructor with custom converters between IdxPref and IdPref.

Parameters:

recommenderData - preference data to be transposed

idPrefFun - converter from item IdPref to user IdPref

idxPrefFun - converter from item IdxPref to item IdxPref

Method Detail

user2uidx

public int user2uidx(I u)

Description copied from interface: FastUserIndex

Returns the index assigned to the user.

Specified by:

user2uidx in interface FastUserIndex<I>

Parameters:

u - user

Returns:

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

uidx2user

public I uidx2user(int uidx)

Description copied from interface: FastUserIndex

Returns the user represented with the index.

Specified by:

uidx2user in interface FastUserIndex<I>

Parameters:

uidx - user index

Returns:

the user whose index is uidx

item2iidx

public int item2iidx(U i)

Description copied from interface: FastItemIndex

Returns the index assigned to the item.

Specified by:

item2iidx in interface FastItemIndex<U>

Parameters:

i - item

Returns:

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

iidx2item

public U iidx2item(int iidx)

Description copied from interface: FastItemIndex

Returns the item represented with the index.

Specified by:

iidx2item in interface FastItemIndex<U>

Parameters:

iidx - item index

Returns:

the item whose index is iidx

numUsers

public int numUsers(int iidx)

Description copied from interface: FastPreferenceData

Returns the number of users who have a preference for the item.

Specified by:

numUsers in interface FastPreferenceData<I,U>

Parameters:

iidx - item index

Returns:

number of users who have a preference for the item

numItems

public int numItems(int uidx)

Description copied from interface: FastPreferenceData

Returns the number of items for which the user has preference for.

Specified by:

numItems in interface FastPreferenceData<I,U>

Parameters:

uidx - user index

Returns:

number of items for which the user has preference for

getUidxPreferences

public Stream<? extends IdxPref> getUidxPreferences(int uidx)

Description copied from interface: FastPreferenceData

Gets the preferences of a user.

Specified by:

getUidxPreferences in interface FastPreferenceData<I,U>

Parameters:

uidx - user index

Returns:

preferences of the user

getIidxPreferences

public Stream<? extends IdxPref> getIidxPreferences(int iidx)

Description copied from interface: FastPreferenceData

Gets the preferences of an item.

Specified by:

getIidxPreferences in interface FastPreferenceData<I,U>

Parameters:

iidx - item index

Returns:

preferences of the item

numUsers

public int numUsers()

Description copied from interface: UserIndex

Counts the number of indexed users.

Specified by:

numUsers in interface UserIndex<I>

Returns:

the total number of users

numUsers

public int numUsers(U i)

Description copied from interface: PreferenceData

Returns the number of users with preference for item i

Specified by:

numUsers in interface PreferenceData<I,U>

Parameters:

i - item

Returns:

number of users with preferences for item i

numItems

public int numItems()

Description copied from interface: ItemIndex

Counts the number of indexed items.

Specified by:

numItems in interface ItemIndex<U>

Returns:

the total number of item

numItems

public int numItems(I u)

Description copied from interface: PreferenceData

Returns the number of items with preference for user u

Specified by:

numItems in interface PreferenceData<I,U>

Parameters:

u - user

Returns:

number of items with preferences for user u

numPreferences

public int numPreferences()

Description copied from interface: PreferenceData

Returns the total number of preferences

Specified by:

numPreferences in interface PreferenceData<I,U>

Returns:

total number of preferences

getAllUsers

public Stream<I> getAllUsers()

Description copied from interface: UserIndex

Retrieves a stream of the indexed users.

Specified by:

getAllUsers in interface UserIndex<I>

Specified by:

getAllUsers in interface FastUserIndex<I>

Returns:

a stream of all the users

getAllItems

public Stream<U> getAllItems()

Description copied from interface: ItemIndex

Retrieves a stream of the indexed items.

Specified by:

getAllItems in interface ItemIndex<U>

Specified by:

getAllItems in interface FastItemIndex<U>

Returns:

a stream of all the items

getUserPreferences

public Stream<? extends IdPref<U>> getUserPreferences(I u)

Description copied from interface: PreferenceData

Returns a stream of the preferences of the user

Specified by:

getUserPreferences in interface PreferenceData<I,U>

Parameters:

u - user

Returns:

stream of preferences

getItemPreferences

public Stream<? extends IdPref<I>> getItemPreferences(U i)

Description copied from interface: PreferenceData

Returns a stream of the preferences of the item

Specified by:

getItemPreferences in interface PreferenceData<I,U>

Parameters:

i - item

Returns:

stream of preferences

getAllUidx

public IntStream getAllUidx()

Description copied from interface: FastUserIndex

Gets all the indices of the users.

Specified by:

getAllUidx in interface FastUserIndex<I>

Returns:

a stream of indexes of users

getAllIidx

public IntStream getAllIidx()

Description copied from interface: FastItemIndex

Gets all the indices of the items.

Specified by:

getAllIidx in interface FastItemIndex<U>

Returns:

a stream of indexes of items

getUidxWithPreferences

public IntStream getUidxWithPreferences()

Description copied from interface: FastPreferenceData

Returns a stream of user indexes who have preferences for items.

Specified by:

getUidxWithPreferences in interface FastPreferenceData<I,U>

Returns:

a stream of user indexes who have preferences for items

getIidxWithPreferences

public IntStream getIidxWithPreferences()

Description copied from interface: FastPreferenceData

Returns a stream of item indexes for which users have preferences.

Specified by:

getIidxWithPreferences in interface FastPreferenceData<I,U>

Returns:

a stream of item indexes for which users have preferences

numUsersWithPreferences

public int numUsersWithPreferences()

Description copied from interface: PreferenceData

Returns the number of users with preferences.

Specified by:

numUsersWithPreferences in interface PreferenceData<I,U>

Returns:

number of users with preferences

numItemsWithPreferences

public int numItemsWithPreferences()

Description copied from interface: PreferenceData

Returns the number of items with preferences.

Specified by:

numItemsWithPreferences in interface PreferenceData<I,U>

Returns:

number of items with preferences

getUsersWithPreferences

public Stream<I> getUsersWithPreferences()

Description copied from interface: PreferenceData

Returns a stream of the users with preferences

Specified by:

getUsersWithPreferences in interface PreferenceData<I,U>

Returns:

stream of users with preferences

getItemsWithPreferences

public Stream<U> getItemsWithPreferences()

Description copied from interface: PreferenceData

Returns a stream of the items with preferences

Specified by:

getItemsWithPreferences in interface PreferenceData<I,U>

Returns:

stream of items with preferences

getUidxIidxs

public it.unimi.dsi.fastutil.ints.IntIterator getUidxIidxs(int uidx)

Description copied from interface: FastPreferenceData

Returns the item idxs of the preferences of a user.

Specified by:

getUidxIidxs in interface FastPreferenceData<I,U>

Parameters:

uidx - user index

Returns:

iterator of the idxs of the items

getUidxVs

public it.unimi.dsi.fastutil.doubles.DoubleIterator getUidxVs(int uidx)

Description copied from interface: FastPreferenceData

Returns the item values of the preferences of a user.

Specified by:

getUidxVs in interface FastPreferenceData<I,U>

Parameters:

uidx - user index

Returns:

iterator of the values of the items

getIidxUidxs

public it.unimi.dsi.fastutil.ints.IntIterator getIidxUidxs(int iidx)

Description copied from interface: FastPreferenceData

Returns the user idxs of the preferences for an item.

Specified by:

getIidxUidxs in interface FastPreferenceData<I,U>

Parameters:

iidx - item index

Returns:

iterator of the idxs of the users.

getIidxVs

public it.unimi.dsi.fastutil.doubles.DoubleIterator getIidxVs(int iidx)

Description copied from interface: FastPreferenceData

Returns the user values of the preferences for an item.

Specified by:

getIidxVs in interface FastPreferenceData<I,U>

Parameters:

iidx - item index

Returns:

iterator of the values of the users

getPreference

public Optional<IdxPref> getPreference(int uidx,
                                       int iidx)

Description copied from interface: FastPointWisePreferenceData

Get preference of a user for an item.

Specified by:

getPreference in interface FastPointWisePreferenceData<I,U>

Parameters:

uidx - user idx

iidx - item idx

Returns:

optional preference for item if it exists

getPreference

public Optional<IdPref<U>> getPreference(I u,
                                         U i)

Description copied from interface: PointWisePreferenceData

Get preference of a user for an item.

Specified by:

getPreference in interface PointWisePreferenceData<I,U>

Parameters:

u - user

i - item

Returns:

optional preference for item if it exists

useIteratorsPreferentially

public boolean useIteratorsPreferentially()

Description copied from interface: FastPreferenceData

Use methods returning IntIterator or DoubleIterator over streams of IdxPref?

Specified by:

useIteratorsPreferentially in interface FastPreferenceData<I,U>

Returns:

yes/no