AfterEffect (Lucene 7.7.0 API)

java.lang.Object
- org.apache.lucene.search.similarities.AfterEffect

Direct Known Subclasses:

AfterEffect.NoAfterEffect, AfterEffectB, AfterEffectL
```
public abstract class AfterEffect
extends Object
```
This class acts as the base class for the implementations of the first normalization of the informative content in the DFR framework. This component is also called the after effect and is defined by the formula Inf₂ = 1 - Prob₂, where Prob₂ measures the information gain.

See Also:

DFRSimilarity

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class AfterEffect.NoAfterEffect
Implementation used when there is no aftereffect.

Constructor Summary

Constructors
Constructor Description

AfterEffect()
Sole constructor.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract Explanation`	`explain(BasicStats stats, float tfn)`	Returns an explanation for the score.
`abstract float`	`score(BasicStats stats, float tfn)`	Returns the aftereffect score.
`abstract String`	`toString()`	Subclasses must override this method to return the code of the after effect formula.

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

- Constructor Detail
  - AfterEffect
```
public AfterEffect()
```
    Sole constructor. (For invocation by subclass constructors, typically implicit.)
- Method Detail
  - score
```
public abstract float score(BasicStats stats,
                            float tfn)
```
    Returns the aftereffect score.
  - explain
```
public abstract Explanation explain(BasicStats stats,
                                    float tfn)
```
    Returns an explanation for the score.
  - toString
```
public abstract String toString()
```
    Subclasses must override this method to return the code of the after effect formula. Refer to the original paper for the list.
    
    Overrides:
    
    toString in class Object