org.lenskit.util.collections

Class TopNLong2DoubleAccumulator

java.lang.Object

org.lenskit.util.collections.TopNLong2DoubleAccumulator

All Implemented Interfaces:

Long2DoubleAccumulator

public final class TopNLong2DoubleAccumulator
extends java.lang.Object
implements Long2DoubleAccumulator

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

Constructor Summary

Constructors

Constructor and Description
TopNLong2DoubleAccumulator(int n) Create a new accumulator to accumulate the top n IDs.

Method Summary

Modifier and Type	Method and Description
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.
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

Methods inherited from interface org.lenskit.util.collections.Long2DoubleAccumulator

putAll

Constructor Detail

TopNLong2DoubleAccumulator

public TopNLong2DoubleAccumulator(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: Long2DoubleAccumulator

Query whether the accumulator is empty.

Specified by:

isEmpty in interface Long2DoubleAccumulator

Returns:

true if the accumulator has no items.

size

public int size()

Description copied from interface: Long2DoubleAccumulator

Get the number of items in the accumulator.

Specified by:

size in interface Long2DoubleAccumulator

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: Long2DoubleAccumulator

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 Long2DoubleAccumulator

Parameters:

item - The item to add to the accumulator.

score - The item’s score.

finishMap

public Long2DoubleMap finishMap()

Description copied from interface: Long2DoubleAccumulator

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 Long2DoubleAccumulator

Returns:

A map of items.

finishSet

public LongSet finishSet()

Description copied from interface: Long2DoubleAccumulator

Accumulate the scored items into a set.

Specified by:

finishSet in interface Long2DoubleAccumulator

Returns:

The set of items accumulated.

finishList

public LongList finishList()

Description copied from interface: Long2DoubleAccumulator

Accumulate the scored items into a list.

Specified by:

finishList in interface Long2DoubleAccumulator

Returns:

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