LMJelinekMercerSimilarity (The Adobe Experience Manager SDK 2022.11.9850.20221116T162329Z-220900)

java.lang.Object
- org.apache.lucene.search.similarities.Similarity
- - org.apache.lucene.search.similarities.SimilarityBase
  - - org.apache.lucene.search.similarities.LMSimilarity
    - - org.apache.lucene.search.similarities.LMJelinekMercerSimilarity

```
public class LMJelinekMercerSimilarity
extends LMSimilarity
```
Language model based on the Jelinek-Mercer smoothing method. From Chengxiang Zhai and John Lafferty. 2001. A study of smoothing methods for language models applied to Ad Hoc information retrieval. In Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (SIGIR '01). ACM, New York, NY, USA, 334-342.
The model has a single parameter, λ. According to said paper, the optimal value depends on both the collection and the query. The optimal value is around 0.1 for title queries and 0.7 for long queries.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.lucene.search.similarities.LMSimilarity
  LMSimilarity.CollectionModel, LMSimilarity.DefaultCollectionModel, LMSimilarity.LMStats
- Nested classes/interfaces inherited from class org.apache.lucene.search.similarities.Similarity
  Similarity.SimScorer, Similarity.SimWeight

Constructor Summary

Constructors
Constructor	Description
`LMJelinekMercerSimilarity(float lambda)`	Instantiates with the specified λ parameter.
`LMJelinekMercerSimilarity(LMSimilarity.CollectionModel collectionModel, float lambda)`	Instantiates with the specified collectionModel and λ parameter.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`float`	`getLambda()`	Returns the λ parameter.
`java.lang.String`	`getName()`	Returns the name of the LM method.

Methods inherited from class org.apache.lucene.search.similarities.LMSimilarity
toString

Methods inherited from class org.apache.lucene.search.similarities.SimilarityBase
computeNorm, computeWeight, getDiscountOverlaps, log2, setDiscountOverlaps, simScorer

Methods inherited from class org.apache.lucene.search.similarities.Similarity
coord, queryNorm

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - LMJelinekMercerSimilarity
```
public LMJelinekMercerSimilarity(LMSimilarity.CollectionModel collectionModel,
                                 float lambda)
```
    Instantiates with the specified collectionModel and λ parameter.
  - LMJelinekMercerSimilarity
```
public LMJelinekMercerSimilarity(float lambda)
```
    Instantiates with the specified λ parameter.
- Method Detail
  - getLambda
```
public float getLambda()
```
    Returns the λ parameter.
  - getName
```
public java.lang.String getName()
```
    Description copied from class: LMSimilarity
    
    Returns the name of the LM method. The values of the parameters should be included as well.
    Used in LMSimilarity.toString()
    .
    
    Specified by:
    
    getName in class LMSimilarity