es.uam.eps.ir.ranksys.core.preference

Class SimplePreferenceData<U,I>

java.lang.Object

es.uam.eps.ir.ranksys.core.preference.SimplePreferenceData<U,I>

Type Parameters:

U - type of the users

I - type of the items

All Implemented Interfaces:

ItemIndex<I>, UserIndex<U>, PreferenceData<U,I>, Serializable

public class SimplePreferenceData<U,I>
extends Object
implements PreferenceData<U,I>, Serializable

Simple map-based preference data

Author:

Saúl Vargas (saul.vargas@uam.es)

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimplePreferenceData(Map<U,List<IdPref<I>>> userMap, Map<I,List<IdPref<U>>> itemMap, int numPreferences) Constructor.

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.
Stream<? extends IdPref<U>>	getItemPreferences(I i) Returns a stream of the preferences of the item
Stream<I>	getItemsWithPreferences() Returns a stream of the items with preferences
Stream<? extends IdPref<I>>	getUserPreferences(U u) Returns a stream of the preferences of the user
Stream<U>	getUsersWithPreferences() Returns a stream of the users with preferences
static <U,I> SimplePreferenceData<U,I>	load(Stream<org.jooq.lambda.tuple.Tuple3<U,I,Double>> tuples) Loads a SimplePreferenceData from a stream of user-item-value triples.
static <U,I,O> SimplePreferenceData<U,I>	load(Stream<org.jooq.lambda.tuple.Tuple4<U,I,Double,O>> tuples, org.jooq.lambda.function.Function4<U,I,Double,O,? extends IdPref<I>> uPrefFun, org.jooq.lambda.function.Function4<U,I,Double,O,? extends IdPref<U>> iPrefFun) Loads an instance of the class from a stream of tuples possibly containing extra information.
int	numItems() Counts the number of indexed items.
int	numItems(U u) Returns the number of items with preference for user u
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(I i) Returns the number of users with preference for item i
int	numUsersWithPreferences() Returns the number of users with preferences.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimplePreferenceData

protected SimplePreferenceData(Map<U,List<IdPref<I>>> userMap,
                               Map<I,List<IdPref<U>>> itemMap,
                               int numPreferences)

Constructor.

Parameters:

userMap - user to preferences map

itemMap - item to preferences map

numPreferences - total number of preferences

Method Detail

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>

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

numUsers

public int numUsers(I i)

Description copied from interface: PreferenceData

Returns the number of users with preference for item i

Specified by:

numUsers in interface PreferenceData<U,I>

Parameters:

i - item

Returns:

number of users with preferences for item i

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>

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

numItems

public int numItems(U u)

Description copied from interface: PreferenceData

Returns the number of items with preference for user u

Specified by:

numItems in interface PreferenceData<U,I>

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<U,I>

Returns:

total number of preferences

getAllUsers

public Stream<U> getAllUsers()

Description copied from interface: UserIndex

Retrieves a stream of the indexed users.

Specified by:

getAllUsers in interface UserIndex<U>

Returns:

a stream of all the users

getAllItems

public Stream<I> getAllItems()

Description copied from interface: ItemIndex

Retrieves a stream of the indexed items.

Specified by:

getAllItems in interface ItemIndex<I>

Returns:

a stream of all the items

getUserPreferences

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

Description copied from interface: PreferenceData

Returns a stream of the preferences of the user

Specified by:

getUserPreferences in interface PreferenceData<U,I>

Parameters:

u - user

Returns:

stream of preferences

getItemPreferences

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

Description copied from interface: PreferenceData

Returns a stream of the preferences of the item

Specified by:

getItemPreferences in interface PreferenceData<U,I>

Parameters:

i - item

Returns:

stream of preferences

numUsersWithPreferences

public int numUsersWithPreferences()

Description copied from interface: PreferenceData

Returns the number of users with preferences.

Specified by:

numUsersWithPreferences in interface PreferenceData<U,I>

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<U,I>

Returns:

number of items with preferences

getUsersWithPreferences

public Stream<U> getUsersWithPreferences()

Description copied from interface: PreferenceData

Returns a stream of the users with preferences

Specified by:

getUsersWithPreferences in interface PreferenceData<U,I>

Returns:

stream of users with preferences

getItemsWithPreferences

public Stream<I> getItemsWithPreferences()

Description copied from interface: PreferenceData

Returns a stream of the items with preferences

Specified by:

getItemsWithPreferences in interface PreferenceData<U,I>

Returns:

stream of items with preferences

load

public static <U,I> SimplePreferenceData<U,I> load(Stream<org.jooq.lambda.tuple.Tuple3<U,I,Double>> tuples)

Loads a SimplePreferenceData from a stream of user-item-value triples.

Type Parameters:

U - user type

I - item type

Parameters:

tuples - user-item-value triples

Returns:

instance of SimplePreferenceData containing the information in the input

load

public static <U,I,O> SimplePreferenceData<U,I> load(Stream<org.jooq.lambda.tuple.Tuple4<U,I,Double,O>> tuples,
                                                     org.jooq.lambda.function.Function4<U,I,Double,O,? extends IdPref<I>> uPrefFun,
                                                     org.jooq.lambda.function.Function4<U,I,Double,O,? extends IdPref<U>> iPrefFun)

Loads an instance of the class from a stream of tuples possibly containing extra information.

Type Parameters:

U - type of user

I - type of item

O - type of additional information

Parameters:

tuples - stream of user-item-value triples

uPrefFun - creator of preference objects

iPrefFun - creator of preference objects

Returns:

a preference data object