LMSimilarity (The Adobe Experience Manager SDK 2021.8.5705.20210810T082946Z-210700)

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

Direct Known Subclasses:

LMDirichletSimilarity, LMJelinekMercerSimilarity
```
public abstract class LMSimilarity
extends SimilarityBase
```
Abstract superclass for language modeling Similarities. The following inner types are introduced:
- LMSimilarity.LMStats, which defines a new statistic, the probability that the collection language model generates the current term;
- LMSimilarity.CollectionModel, which is a strategy interface for object that compute the collection language model p(w|C);
- LMSimilarity.DefaultCollectionModel, an implementation of the former, that computes the term probability as the number of occurrences of the term in the collection, divided by the total number of tokens.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static interface`	`LMSimilarity.CollectionModel`	A strategy for computing the collection language model.
`static class`	`LMSimilarity.DefaultCollectionModel`	Models `p(w\|C)` as the number of occurrences of the term in the collection, divided by the total number of tokens `+ 1`.
`static class`	`LMSimilarity.LMStats`	Stores the collection distribution of the current term.

Nested classes/interfaces inherited from class org.apache.lucene.search.similarities.Similarity
Similarity.SimScorer, Similarity.SimWeight

Constructor Summary

Constructors
Constructor	Description
`LMSimilarity()`	Creates a new instance with the default collection language model.
`LMSimilarity(LMSimilarity.CollectionModel collectionModel)`	Creates a new instance with the specified collection language model.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract String`	`getName()`	Returns the name of the LM method.
`String`	`toString()`	Returns the name of the LM method.

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
  - LMSimilarity
```
public LMSimilarity(LMSimilarity.CollectionModel collectionModel)
```
    Creates a new instance with the specified collection language model.
  - LMSimilarity
```
public LMSimilarity()
```
    Creates a new instance with the default collection language model.
- Method Detail
  - getName
```
public abstract String getName()
```
    Returns the name of the LM method. The values of the parameters should be included as well.
    Used in toString()
    .
  - toString
```
public String toString()
```
    Returns the name of the LM method. If a custom collection model strategy is used, its name is included as well.
    
    Specified by:
    
    toString in class SimilarityBase
    
    See Also:
    
    getName(), LMSimilarity.CollectionModel.getName(), LMSimilarity.DefaultCollectionModel