es.uam.eps.ir.ranksys.fast.index

Interface FastItemIndex<I>

Type Parameters:

I - type of the items

All Superinterfaces:

ItemIndex<I>

All Known Subinterfaces:

FastFeatureData<I,F,V>, FastPointWisePreferenceData<U,I>, FastPreferenceData<U,I>, FastPreferenceSampler<U,I>, FastRecommender<U,I>

All Known Implementing Classes:

AbstractCODECPreferenceData, AbstractFastFeatureData, AbstractFastPreferenceData, AbstractFastPreferenceSampler, AbstractFastRecommender, BinaryCODECPreferenceData, CachedItemNeighborhood, Factorization, FastEnsembleRecommender, FastRankingRecommender, FMRecommender, InvertedItemNeighborhood, ItemNeighborhood, ItemNeighborhoodRecommender, ItemSimilarity, IteratorsAbstractFastPreferenceData, LDARecommender, MFRecommender, PopularityRecommender, PreferenceFM, RandomRecommender, RatingCODECPreferenceData, RerankingRecommender, SetCosineItemSimilarity, SetJaccardItemSimilarity, SimpleFastFeatureData, SimpleFastItemIndex, SimpleFastPreferenceData, StreamsAbstractFastPreferenceData, ThresholdItemNeighborhood, TopKItemNeighborhood, TransposedPreferenceData, UserNeighborhoodRecommender, VectorCosineItemSimilarity, VectorJaccardItemSimilarity

public interface FastItemIndex<I>
extends ItemIndex<I>

Fast version of ItemIndex, where items are internally represented with numerical indices from 0 (inclusive) to the number of indexed items (exclusive).

Author:

Saúl Vargas (saul.vargas@uam.es)

Method Summary

Modifier and Type	Method and Description
default boolean	containsItem(I i) Checks whether the index contains an item.
default IntStream	getAllIidx() Gets all the indices of the items.
default Stream<I>	getAllItems() Retrieves a stream of the indexed items.
I	iidx2item(int iidx) Returns the item represented with the index.
default Tuple2od<I>	iidx2item(Tuple2id tuple) Applies FastItemIndex::iidx2item to the first element of the tuple.
default <V> org.jooq.lambda.tuple.Tuple2<I,V>	iidx2item(Tuple2io<V> tuple) Applies FastItemIndex::iidx2item to the first element of the tuple.
int	item2iidx(I i) Returns the index assigned to the item.
default <V> Tuple2io<V>	item2iidx(org.jooq.lambda.tuple.Tuple2<I,V> tuple) Applies FastItemIndex::item2iidx to the first element of the tuple.
default Tuple2id	item2iidx(Tuple2od<I> tuple) Applies FastItemIndex::item2iidx to the first element of the tuple.

Methods inherited from interface es.uam.eps.ir.ranksys.core.index.ItemIndex

numItems

Method Detail

containsItem

default 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

getAllItems

default 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

getAllIidx

default IntStream getAllIidx()

Gets all the indices of the items.

Returns:

a stream of indexes of items

item2iidx

int item2iidx(I i)

Returns the index assigned to the item.

Parameters:

i - item

Returns:

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

iidx2item

I iidx2item(int iidx)

Returns the item represented with the index.

Parameters:

iidx - item index

Returns:

the item whose index is iidx

item2iidx

default <V> Tuple2io<V> item2iidx(org.jooq.lambda.tuple.Tuple2<I,V> tuple)

Applies FastItemIndex::item2iidx to the first element of the tuple.

Type Parameters:

V - type of value

Parameters:

tuple - item-value tuple

Returns:

iidx-value tuple

iidx2item

default <V> org.jooq.lambda.tuple.Tuple2<I,V> iidx2item(Tuple2io<V> tuple)

Applies FastItemIndex::iidx2item to the first element of the tuple.

Type Parameters:

V - type of value

Parameters:

tuple - iidx-value tuple

Returns:

item-value tuple

item2iidx

default Tuple2id item2iidx(Tuple2od<I> tuple)

Applies FastItemIndex::item2iidx to the first element of the tuple.

Parameters:

tuple - item-double tuple

Returns:

iidx-double tuple

iidx2item

default Tuple2od<I> iidx2item(Tuple2id tuple)

Applies FastItemIndex::iidx2item to the first element of the tuple.

Parameters:

tuple - iidx-double tuple

Returns:

item-double tuple