Module org.apache.lucene.core

Package org.apache.lucene.search

Class VectorSimilarityCollector

java.lang.Object

org.apache.lucene.search.AbstractKnnCollector

org.apache.lucene.search.VectorSimilarityCollector

All Implemented Interfaces:

KnnCollector

class VectorSimilarityCollector
extends AbstractKnnCollector

Perform a similarity-based graph search.

Field Summary

Fields

Modifier and Type	Field	Description
private float	maxSimilarity
private final float	resultSimilarity
private final List<ScoreDoc>	scoreDocList
private final float	traversalSimilarity

Fields inherited from class org.apache.lucene.search.AbstractKnnCollector

visitedCount

Constructor Summary

Constructors

Constructor	Description
VectorSimilarityCollector(float traversalSimilarity, float resultSimilarity, long visitLimit)	Perform a similarity-based graph search.

Method Summary

Modifier and Type	Method	Description
boolean	collect(int docId, float similarity)	Collect the provided docId and include in the result set.
float	minCompetitiveSimilarity()	This method is utilized during search to ensure only competitive results are explored.
int	numCollected()
TopDocs	topDocs()	This drains the collected nearest kNN results and returns them in a new TopDocs collection, ordered by score descending.

Methods inherited from class org.apache.lucene.search.AbstractKnnCollector

earlyTerminated, incVisitedCount, k, visitedCount, visitLimit

Methods inherited from class java.lang.Object

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

Field Details

traversalSimilarity

private final float traversalSimilarity

resultSimilarity

private final float resultSimilarity

maxSimilarity

private float maxSimilarity

scoreDocList

private final List<ScoreDoc> scoreDocList

Constructor Details

VectorSimilarityCollector

public VectorSimilarityCollector(float traversalSimilarity,
 float resultSimilarity,
 long visitLimit)

Perform a similarity-based graph search. The graph is traversed till better scoring nodes are available, or the best candidate is below traversalSimilarity. All traversed nodes above resultSimilarity are collected.

Parameters:

traversalSimilarity - (lower) similarity score for graph traversal.

resultSimilarity - (higher) similarity score for result collection.

visitLimit - limit on number of nodes to visit.

Method Details

collect

public boolean collect(int docId,
 float similarity)

Description copied from interface: KnnCollector

Collect the provided docId and include in the result set.

Specified by:

collect in interface KnnCollector

Specified by:

collect in class AbstractKnnCollector

Parameters:

docId - of the vector to collect

similarity - its calculated similarity

Returns:

true if the vector is collected

minCompetitiveSimilarity

public float minCompetitiveSimilarity()

Description copied from interface: KnnCollector

This method is utilized during search to ensure only competitive results are explored.

Consequently, if this results collector wants to collect `k` results, this should return Float.NEGATIVE_INFINITY when not full.

When full, the minimum score should be returned.

Specified by:

minCompetitiveSimilarity in interface KnnCollector

Specified by:

minCompetitiveSimilarity in class AbstractKnnCollector

Returns:

the current minimum competitive similarity in the collection

topDocs

public TopDocs topDocs()

Description copied from interface: KnnCollector

This drains the collected nearest kNN results and returns them in a new TopDocs collection, ordered by score descending. NOTE: This is generally a destructive action and the collector should not be used after topDocs() is called.

Specified by:

topDocs in interface KnnCollector

Specified by:

topDocs in class AbstractKnnCollector

Returns:

The collected top documents

numCollected

public int numCollected()

Specified by:

numCollected in class AbstractKnnCollector