Package org.apache.lucene.queries.intervals

Class IntervalQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.queries.intervals.IntervalQuery

public final class IntervalQuery
extends Query

A query that retrieves documents containing intervals returned from an IntervalsSource Static constructor functions for various different sources can be found in the Intervals class Scores for this query are computed as a function of the sloppy frequency of intervals appearing in a particular document. Sloppy frequency is calculated from the number of matching intervals, and their width, with wider intervals contributing lower values. The scores can be adjusted with two optional parameters:

• pivot - the sloppy frequency value at which the overall score of the document will equal 0.5. The default value is 1
• exp - higher values of this parameter make the function grow more slowly below the pivot and faster higher than the pivot. The default value is 1

Optimal values for both pivot and exp depend on the type of queries and corpus of documents being queried. Scores are bounded to between 0 and 1. For higher contributions, wrap the query in a BoostQuery

Constructor Summary

Constructors

Constructor	Description
IntervalQuery(String field, IntervalsSource intervalsSource)	Create a new IntervalQuery
IntervalQuery(String field, IntervalsSource intervalsSource, float pivot)	Create a new IntervalQuery with a scoring pivot
IntervalQuery(String field, IntervalsSource intervalsSource, float pivot, float exp)	Create a new IntervalQuery with a scoring pivot and exponent

Method Summary

Modifier and Type	Method	Description
Weight	createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)	Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object o)	Override and implement query instance equivalence properly in a subclass.
String	getField()	The field to query
int	hashCode()	Override and implement query hash code properly in a subclass.
String	toString(String field)	Prints a query to a string, with field assumed to be the default field and omitted.
void	visit(QueryVisitor visitor)	Recurse through the query tree, visiting any child queries

Methods inherited from class org.apache.lucene.search.Query

classHash, rewrite, sameClassAs, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

IntervalQuery

public IntervalQuery(String field,
                     IntervalsSource intervalsSource)

Create a new IntervalQuery

Parameters:

field - the field to query

intervalsSource - an IntervalsSource to retrieve intervals from

IntervalQuery

public IntervalQuery(String field,
                     IntervalsSource intervalsSource,
                     float pivot)

Create a new IntervalQuery with a scoring pivot

Parameters:

field - the field to query

intervalsSource - an IntervalsSource to retrieve intervals from

pivot - the sloppy frequency value at which the score will be 0.5, must be within (0, +Infinity)

IntervalQuery

public IntervalQuery(String field,
                     IntervalsSource intervalsSource,
                     float pivot,
                     float exp)

Create a new IntervalQuery with a scoring pivot and exponent

Parameters:

field - the field to query

intervalsSource - an IntervalsSource to retrieve intervals from

pivot - the sloppy frequency value at which the score will be 0.5, must be within (0, +Infinity)

exp - exponent, higher values make the function grow slower before 'pivot' and faster after 'pivot', must be in (0, +Infinity)

Method Detail

getField

public String getField()

The field to query

toString

public String toString(String field)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

Specified by:

toString in class Query

createWeight

public Weight createWeight(IndexSearcher searcher,
                           ScoreMode scoreMode,
                           float boost)
                    throws IOException

Description copied from class: Query

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Overrides:

createWeight in class Query

scoreMode - How the produced scorers will be consumed.

boost - The boost that is propagated by the parent queries.

Throws:

IOException

visit

public void visit(QueryVisitor visitor)

Description copied from class: Query

Recurse through the query tree, visiting any child queries

Overrides:

visit in class Query

Parameters:

visitor - a QueryVisitor to be called by each query in the tree

equals

public boolean equals(Object o)

Description copied from class: Query

Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly. Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical that other instance. Utility methods are provided for certain repetitive code.

Specified by:

equals in class Query

See Also:

Query.sameClassAs(Object), Query.classHash()

hashCode

public int hashCode()

Description copied from class: Query

Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.

Specified by:

hashCode in class Query

See Also:

Query.equals(Object)