IndexReaderFunctions (Lucene 8.3.0 API)

java.lang.Object
- org.apache.lucene.queries.function.IndexReaderFunctions

```
public final class IndexReaderFunctions
extends Object
```
Class exposing static helper methods for generating DoubleValuesSource instances over some IndexReader statistics

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static DoubleValuesSource`	`docCount(String field)` Creates a constant value source returning the docCount for a given field
`static DoubleValuesSource`	`docFreq(Term term)` Creates a constant value source returning the docFreq of a given term
`static DoubleValuesSource`	`maxDoc()` Creates a constant value source returning the index's maxDoc
`static DoubleValuesSource`	`numDeletedDocs()` Creates a constant value source returning the number of deleted docs in the index
`static DoubleValuesSource`	`numDocs()` Creates a constant value source returning the index's numDocs
`static DoubleValuesSource`	`sumDocFreq(String field)` Creates a constant value source returning the sumDocFreq for a given field
`static LongValuesSource`	`sumTotalTermFreq(String field)` Creates a constant value source returning the sumTotalTermFreq for a field
`static DoubleValuesSource`	`termFreq(Term term)` Creates a value source that returns the term freq of a given term for each document
`static DoubleValuesSource`	`totalTermFreq(Term term)` Creates a constant value source returning the totalTermFreq for a given term

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

- Method Detail
  - docFreq
```
public static DoubleValuesSource docFreq(Term term)
```
    Creates a constant value source returning the docFreq of a given term
    
    See Also:
    
    IndexReader.docFreq(Term)
  - maxDoc
```
public static DoubleValuesSource maxDoc()
```
    Creates a constant value source returning the index's maxDoc
    
    See Also:
    
    IndexReader.maxDoc()
  - numDocs
```
public static DoubleValuesSource numDocs()
```
    Creates a constant value source returning the index's numDocs
    
    See Also:
    
    IndexReader.numDocs()
  - numDeletedDocs
```
public static DoubleValuesSource numDeletedDocs()
```
    Creates a constant value source returning the number of deleted docs in the index
    
    See Also:
    
    IndexReader.numDeletedDocs()
  - sumTotalTermFreq
```
public static LongValuesSource sumTotalTermFreq(String field)
```
    Creates a constant value source returning the sumTotalTermFreq for a field
    
    See Also:
    
    IndexReader.getSumTotalTermFreq(String)
  - termFreq
```
public static DoubleValuesSource termFreq(Term term)
```
    Creates a value source that returns the term freq of a given term for each document
    
    See Also:
    
    PostingsEnum.freq()
  - totalTermFreq
```
public static DoubleValuesSource totalTermFreq(Term term)
```
    Creates a constant value source returning the totalTermFreq for a given term
    
    See Also:
    
    IndexReader.totalTermFreq(Term)
  - sumDocFreq
```
public static DoubleValuesSource sumDocFreq(String field)
```
    Creates a constant value source returning the sumDocFreq for a given field
    
    See Also:
    
    IndexReader.getSumDocFreq(String)
  - docCount
```
public static DoubleValuesSource docCount(String field)
```
    Creates a constant value source returning the docCount for a given field
    
    See Also:
    
    IndexReader.getDocCount(String)

Class IndexReaderFunctions

Method Summary

Methods inherited from class java.lang.Object

Method Detail

docFreq

maxDoc

numDocs

numDeletedDocs

sumTotalTermFreq

termFreq

totalTermFreq

sumDocFreq

docCount