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)
boolean	equals(Object o)
String	getField()	The field to query
int	hashCode()
String	toString(String field)
void	visit(QueryVisitor visitor)

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 Details

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 Details

getField

public String getField()

The field to query

toString

public String toString(String field)

Specified by:

toString in class Query

createWeight

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

Overrides:

createWeight in class Query

Throws:

IOException

visit

public void visit(QueryVisitor visitor)

Specified by:

visit in class Query

equals

public boolean equals(Object o)

Specified by:

equals in class Query

hashCode

public int hashCode()

Specified by:

hashCode in class Query