# Package org.apache.lucene.queries.function.valuesource

package org.apache.lucene.queries.function.valuesource
A variety of functions to use with FunctionQuery.

Related Packages
Package
Description
org.apache.lucene.queries.function
Queries that compute score based upon a function.
org.apache.lucene.queries.function.docvalues
FunctionValues for different data types.
Classes
Class
Description
BoolFunction
Abstract parent class for those `ValueSource` implementations which apply boolean logic to their values
ByteKnnVectorFieldSource
An implementation for retrieving `FunctionValues` instances for byte knn vectors fields.
BytesRefFieldSource
An implementation for retrieving `FunctionValues` instances for string based fields.
ByteVectorSimilarityFunction
`ByteVectorSimilarityFunction` returns a similarity function between two knn vectors with byte elements.
ComparisonBoolFunction
Base class for comparison operators useful within an "if"/conditional.
ConstKnnByteVectorValueSource
Function that returns a constant byte vector value for every document.
ConstKnnFloatValueSource
Function that returns a constant float vector value for every document.
ConstNumberSource
`ConstNumberSource` is the base class for all constant numbers
ConstValueSource
`ConstValueSource` returns a constant for all documents
DefFunction
`ValueSource` implementation which only returns the values from the provided ValueSources which are available for a particular docId.
DivFloatFunction
Function to divide "a" by "b"
DocFreqValueSource
`DocFreqValueSource` returns the number of documents containing the term.
DoubleConstValueSource
Function that returns a constant double value for every document.
DoubleFieldSource
Obtains double field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
DualFloatFunction
Abstract `ValueSource` implementation which wraps two ValueSources and applies an extendible float function to their values.
EnumFieldSource
Obtains int field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
FieldCacheSource
A base class for ValueSource implementations that retrieve values for a single field from DocValues.
FloatFieldSource
Obtains float field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
FloatKnnVectorFieldSource
An implementation for retrieving `FunctionValues` instances for float knn vectors fields.
FloatVectorSimilarityFunction
`FloatVectorSimilarityFunction` returns a similarity function between two knn vectors with float elements.
IDFValueSource
Function that returns `#idf(long, long)` for every document.
IfFunction
Depending on the boolean value of the `ifSource` function, returns the value of the `trueSource` or `falseSource` function.
IntFieldSource
Obtains int field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
JoinDocFreqValueSource
Use a field value and find the Document Frequency within another field.
LinearFloatFunction
`LinearFloatFunction` implements a linear function over another `ValueSource`.
LiteralValueSource
Pass a the field value through as a String, no matter the type // Q: doesn't this mean it's a "string"?
LongFieldSource
Obtains long field values from `LeafReader.getNumericDocValues(java.lang.String)` and makes those values available as other numeric types, casting as needed.
MaxDocValueSource
Returns the value of `IndexReader.maxDoc()` for every document.
MaxFloatFunction
`MaxFloatFunction` returns the max of its components.
MinFloatFunction
`MinFloatFunction` returns the min of its components.
MultiBoolFunction
Abstract `ValueSource` implementation which wraps multiple ValueSources and applies an extendible boolean function to their values.
MultiFloatFunction
Abstract `ValueSource` implementation which wraps multiple ValueSources and applies an extendible float function to their values.
MultiFunction
Abstract parent class for `ValueSource` implementations that wrap multiple ValueSources and apply their own logic.
MultiValuedDoubleFieldSource
Obtains double field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValuedFloatFieldSource
Obtains float field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValuedIntFieldSource
Obtains int field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValuedLongFieldSource
Obtains long field values from `LeafReader.getSortedNumericDocValues(java.lang.String)` and using a `SortedNumericSelector` it gives a single-valued ValueSource view of a field.
MultiValueSource
A `ValueSource` that abstractly represents `ValueSource`s for poly fields, and other things.
NormValueSource
Function that returns the decoded norm for every document.
NumDocsValueSource
Returns the value of `IndexReader.numDocs()` for every document.
PowFloatFunction
Function to raise the base "a" to the power "b"
ProductFloatFunction
`ProductFloatFunction` returns the product of its components.
QueryValueSource
`QueryValueSource` returns the relevance score of the query
RangeMapFloatFunction
`RangeMapFloatFunction` implements a map function over another `ValueSource` whose values fall within min and max inclusive to target.
ReciprocalFloatFunction
`ReciprocalFloatFunction` implements a reciprocal function f(x) = a/(mx+b), based on the float value of a field or function as exported by `ValueSource`.
ScaleFloatFunction
Scales values to be between min and max.
SimpleBoolFunction
`BoolFunction` implementation which applies an extendible boolean function to the values of a single wrapped `ValueSource`.
SimpleFloatFunction
A simple float function with a single argument
SingleFunction
A function with a single argument
SortedSetFieldSource
Retrieves `FunctionValues` instances for multi-valued string based fields.
SumFloatFunction
`SumFloatFunction` returns the sum of its components.
SumTotalTermFreqValueSource
`SumTotalTermFreqValueSource` returns the number of tokens.
TermFreqValueSource
Function that returns `PostingsEnum.freq()` for the supplied term in every document.
TFValueSource
Function that returns `TFIDFSimilarity.tf(float)` for every document.
TotalTermFreqValueSource
`TotalTermFreqValueSource` returns the total term freq (sum of term freqs across all documents).
VectorFieldFunction
An implementation for retrieving `FunctionValues` instances for knn vectors fields.
VectorSimilarityFunction
`VectorSimilarityFunction` returns a similarity function between two knn vectors.
VectorValueSource
Converts individual ValueSource instances to leverage the FunctionValues *Val functions that work with multiple values, i.e.