Class CustomScoreProvider

An instance of this subclass should be returned by GetCustomScoreProvider(IndexReader), if you want to modify the custom score calculation of a CustomScoreQuery.

Since Lucene 2.9, queries operate on each segment of an Index separately, so overriding the similar (now deprecated) methods in CustomScoreQuery is no longer suitable, as the supplied doc ID is per-segment and without knowledge of the IndexReader you cannot access the document or FieldCache.

@lucene.experimental @since 2.9.2

Inheritance
System.Object
CustomScoreProvider
Namespace:
Assembly: Lucene.Net.NetCore.dll
Syntax
public class CustomScoreProvider : object

Constructors

Name Description
CustomScoreProvider(IndexReader)

Creates a new instance of the provider class for the given IndexReader.

Fields

Name Description
reader

Methods

Name Description
CustomExplain(Int32, Explanation, Explanation)

Explain the custom score. Whenever overriding CustomScore(Int32, Single, Single), this method should also be overridden to provide the correct explanation for the part of the custom scoring.
CustomExplain(Int32, Explanation, Explanation[])

Explain the custom score. Whenever overriding CustomScore(Int32, Single, Single[]), this method should also be overridden to provide the correct explanation for the part of the custom scoring.
CustomScore(Int32, Single, Single)

Compute a custom score by the subQuery score and the ValueSourceQuery score.

Subclasses can override this method to modify the custom score.

If your custom scoring is different than the default herein you should override at least one of the two customScore() methods. If the number of ValueSourceQueries is always < 2 it is sufficient to override this customScore() method, which is simpler.

The default computation herein is a multiplication of the two scores:

    ModifiedScore = subQueryScore * valSrcScore

CustomScore(Int32, Single, Single[])
  • Compute a custom score by the subQuery score and a number of ValueSourceQuery scores.

    Subclasses can override this method to modify the custom score.

    If your custom scoring is different than the default herein you should override at least one of the two customScore() methods. If the number of ValueSourceQueries is always < 2 it is sufficient to override the other CustomScore(Int32, Single, Single) method, which is simpler.

    The default computation herein is a multiplication of given scores: 

      ModifiedScore = valSrcScore * valSrcScores[0] * valSrcScores[1] * ...