org.lenskit.util

Class TopNScoredIdAccumulator

java.lang.Object

org.lenskit.util.TopNScoredIdAccumulator

All Implemented Interfaces:

ScoredIdAccumulator

public final class TopNScoredIdAccumulator
extends Object
implements ScoredIdAccumulator

Accumulate the top N scored IDs. IDs are sorted by their associated scores.

Constructor Summary

Constructors

Constructor and Description
TopNScoredIdAccumulator(int n) Create a new accumulator to accumulate the top n IDs.

Method Summary

Modifier and Type	Method and Description
List<ScoredId>	finish() Accumulate the scores into a sorted scored list and reset the accumulator.
LongList	finishList() Accumulate the scored items into a list.
Long2DoubleMap	finishMap() Accumulate the scores into a map and reset the accumulator.
LongSet	finishSet() Accumulate the scored items into a set.
MutableSparseVector	finishVector() Accumulate the scores into a mutable sparse vector and reset the accumulator.
boolean	isEmpty() Query whether the accumulator is empty.
void	put(long item, double score) Put a new item in the accumulator.
int	size() Get the number of items in the accumulator.

Methods inherited from class java.lang.Object

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

Constructor Detail

TopNScoredIdAccumulator

public TopNScoredIdAccumulator(int n)

Create a new accumulator to accumulate the top n IDs.

Parameters:

n - The number of IDs to retain.

Method Detail

isEmpty

public boolean isEmpty()

Description copied from interface: ScoredIdAccumulator

Query whether the accumulator is empty.

Specified by:

isEmpty in interface ScoredIdAccumulator

Returns:

true if the accumulator has no items.

size

public int size()

Description copied from interface: ScoredIdAccumulator

Get the number of items in the accumulator.

Specified by:

size in interface ScoredIdAccumulator

Returns:

The number of items accumulated so far, up to the maximum items desired from the accumulator.

put

public void put(long item,
                double score)

Description copied from interface: ScoredIdAccumulator

Put a new item in the accumulator. Putting the same item twice does not replace the previous entry - it adds a new entry with the same ID.

Specified by:

put in interface ScoredIdAccumulator

Parameters:

item - The item to add to the accumulator.

score - The item’s score.

finish

public List<ScoredId> finish()

Description copied from interface: ScoredIdAccumulator

Accumulate the scores into a sorted scored list and reset the accumulator. Items are sorted in decreasing order of score.

After this method is called, the accumulator is ready for another accumulation.

Specified by:

finish in interface ScoredIdAccumulator

Returns:

The sorted, scored list of items.

finishVector

public MutableSparseVector finishVector()

Description copied from interface: ScoredIdAccumulator

Accumulate the scores into a mutable sparse vector and reset the accumulator.

After this method is called, the accumulator is ready for another accumulation.

Specified by:

finishVector in interface ScoredIdAccumulator

Returns:

A MutableSparseVector of items.

finishMap

public Long2DoubleMap finishMap()

Description copied from interface: ScoredIdAccumulator

Accumulate the scores into a map and reset the accumulator.

After this method is called, the accumulator is ready for another accumulation.

Specified by:

finishMap in interface ScoredIdAccumulator

Returns:

A map of items.

finishSet

public LongSet finishSet()

Description copied from interface: ScoredIdAccumulator

Accumulate the scored items into a set.

Specified by:

finishSet in interface ScoredIdAccumulator

Returns:

The set of items accumulated.

finishList

public LongList finishList()

Description copied from interface: ScoredIdAccumulator

Accumulate the scored items into a list.

Specified by:

finishList in interface ScoredIdAccumulator

Returns:

The list of items accumulated, in decreasing order of score.