com.esri.gpt.catalog.lucene
Class SpatialRankingValueSource

java.lang.Object
  org.apache.lucene.search.function.ValueSource
      com.esri.gpt.catalog.lucene.SpatialRankingValueSource

All Implemented Interfaces:

Serializable

public class SpatialRankingValueSource
extends ValueSource

An implementation of the Lucene ValueSource model to support spatial relevance ranking.

The algorithm is implemented as envelope on envelope overlays rather than complex polygon on complex polygon overlays.

Spatial relevance scoring algorithm:
queryArea = the area of the input query envelope
targetArea = the area of the target envelope (per Lucene document)
intersectionArea = the area of the intersection for the query/target envelopes
queryPower = the weighting power associated with the query envelope (default = 1.0)
targetPower = the weighting power associated with the target envelope (default = 1.0)
queryPower and targetPower are initialized from gpt.xml configuration parameters:
/gptConfig/catalog/parameter@key="spatialRelevance.queryPower" and
/gptConfig/catalog/parameter@key="spatialRelevance.queryPower"
queryRatio = intersectionArea / queryArea;
targetRatio = intersectionArea / targetArea;
queryFactor = Math.pow(queryRatio,queryPower);
targetFactor = Math.pow(targetRatio,targetPower);
score = queryFactor * targetFactor;

See Also:

Serialized Form

Constructor Summary

SpatialRankingValueSource(Envelope queryEnvelope, double queryPower, double targetPower)
Constructor.

Method Summary

String	description() Returns the ValueSource description.
boolean	equals(Object o) Determines if this ValueSource is equal to another.
String	getDelimiterQueryParameters() Returns the delimited query parameters.
DocValues	getValues(IndexReader reader) Returns the DocValues used by the function query.
int	hashCode() Returns the ValueSource hash code.

Methods inherited from class org.apache.lucene.search.function.ValueSource

toString

Methods inherited from class java.lang.Object

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

Constructor Detail

SpatialRankingValueSource

public SpatialRankingValueSource(Envelope queryEnvelope,
                                 double queryPower,
                                 double targetPower)

Constructor.

Parameters:

queryEnvelope - the query envelope

queryPower - the query power (scoring algorithm)

targetPower - the target power (scoring algorithm)

Method Detail

description

public String description()

Returns the ValueSource description.

Specified by:

description in class ValueSource

Returns:

the description

equals

public boolean equals(Object o)

Determines if this ValueSource is equal to another.

Specified by:

equals in class ValueSource

Parameters:

o - the ValueSource to compare

Returns:

true if the two objects are based upon the same query envelope

getDelimiterQueryParameters

public String getDelimiterQueryParameters()

Returns the delimited query parameters.
Applies to ValueSource.equals and ValueSource.hashCode.

Returns:

the delimited parameters

getValues

public DocValues getValues(IndexReader reader)
                    throws IOException

Returns the DocValues used by the function query.

Specified by:

getValues in class ValueSource

Parameters:

reader - the index reader

Returns:

the values

Throws:

IOException

hashCode

public int hashCode()

Returns the ValueSource hash code.

Specified by:

hashCode in class ValueSource

Returns:

the hash code