Class RandomSimilarityProvider

Similarity implementation that randomizes Similarity implementations per-field.

The choices are 'sticky', so the selected algorithm is always used for the same field.
Inheritance
object
Similarity
PerFieldSimilarityWrapper
RandomSimilarityProvider
Inherited Members
PerFieldSimilarityWrapper.ComputeNorm(FieldInvertState)
PerFieldSimilarityWrapper.GetSimScorer(Similarity.SimWeight, AtomicReaderContext)
Namespace: Lucene.Net.Search
Assembly: Lucene.Net.TestFramework.dll
Syntax
public class RandomSimilarityProvider : PerFieldSimilarityWrapper

Constructors

RandomSimilarityProvider(Random)

Similarity implementation that randomizes Similarity implementations per-field.

The choices are 'sticky', so the selected algorithm is always used for the same field.
Declaration
public RandomSimilarityProvider(Random random)
Parameters
Type Name Description
Random random

Methods

Coord(int, int)

Hook to integrate coordinate-level matching.

By default this is disabled (returns 1), as with most modern models this will only skew performance, but some implementations such as Lucene.Net.Search.Similarities.TFIDFSimilarity override this.
Declaration
public override float Coord(int overlap, int maxOverlap)
Parameters
Type Name Description
int overlap

the number of query terms matched in the document
int maxOverlap

the total number of terms in the query
Returns
Type Description
float

a score factor based on term overlap with the query
Overrides

Get(string)

Returns a Lucene.Net.Search.Similarities.Similarity for scoring a field.

Declaration
public override Similarity Get(string field)
Parameters
Type Name Description
string field
Returns
Type Description
Similarity
Overrides

QueryNorm(float)

Computes the normalization value for a query given the sum of the normalized weights Lucene.Net.Search.Similarities.Similarity.SimWeight.GetValueForNormalization() of each of the query terms. this value is passed back to the weight (Normalize(float, float) of each query term, to provide a hook to attempt to make scores from different queries comparable.

By default this is disabled (returns 1), but some implementations such as Lucene.Net.Search.Similarities.TFIDFSimilarity override this.
Declaration
public override float QueryNorm(float sumOfSquaredWeights)
Parameters
Type Name Description
float sumOfSquaredWeights
Returns
Type Description
float

a normalization factor for query weights
Overrides

ToString()

Returns a string that represents the current object.

Declaration
public override string ToString()
Returns
Type Description
string

A string that represents the current object.
Overrides