Package org.apache.lucene.spatial.vector
Class PointVectorStrategy
java.lang.Object
org.apache.lucene.spatial.SpatialStrategy
org.apache.lucene.spatial.vector.PointVectorStrategy
Simple
SpatialStrategy which represents Points in two numeric fields. The Strategy's best
feature is decent distance sort.
Characteristics:
- Only indexes points; just one per field value.
- Can query by a rectangle or circle.
SpatialOperation.IntersectsandSpatialOperation.IsWithinis supported.- Requires DocValues for
SpatialStrategy.makeDistanceValueSource(org.locationtech.spatial4j.shape.Point)and for searching with a Circle.
Implementation:
This is a simple Strategy. Search works with a pair of range queries on two DoublePoints representing x & y fields. A Circle query does the same bbox query but adds a
ValueSource filter on SpatialStrategy.makeDistanceValueSource(org.locationtech.spatial4j.shape.Point).
One performance shortcoming with this strategy is that a scenario involving both a search using a Circle and sort will result in calculations for the spatial distance being done twice -- once for the filter and second for the sort.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final FieldTypepointValues, docValues, and nothing else.static final Stringstatic final StringFields inherited from class org.apache.lucene.spatial.SpatialStrategy
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Constructor Summary
ConstructorsConstructorDescriptionPointVectorStrategy(org.locationtech.spatial4j.context.SpatialContext ctx, String fieldNamePrefix, FieldType fieldType) Create a new instance configured with the provided FieldType options. -
Method Summary
Modifier and TypeMethodDescriptionField[]createIndexableFields(org.locationtech.spatial4j.shape.Point point) Field[]createIndexableFields(org.locationtech.spatial4j.shape.Shape shape) Returns the IndexableField(s) from theshapethat are to be added to theDocument.makeDistanceValueSource(org.locationtech.spatial4j.shape.Point queryPoint, double multiplier) Make a ValueSource returning the distance between the center of the indexed shape andqueryPoint.makeQuery(SpatialArgs args) static PointVectorStrategynewInstance(org.locationtech.spatial4j.context.SpatialContext ctx, String fieldNamePrefix) Create a newPointVectorStrategyinstance that usesDoublePointandDoublePoint.newRangeQuery(java.lang.String, double, double)Methods inherited from class org.apache.lucene.spatial.SpatialStrategy
getFieldName, getSpatialContext, makeDistanceValueSource, makeRecipDistanceValueSource, toString
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Field Details
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DEFAULT_FIELDTYPE
pointValues, docValues, and nothing else. -
SUFFIX_X
- See Also:
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SUFFIX_Y
- See Also:
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Constructor Details
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PointVectorStrategy
public PointVectorStrategy(org.locationtech.spatial4j.context.SpatialContext ctx, String fieldNamePrefix, FieldType fieldType) Create a new instance configured with the provided FieldType options. SeeDEFAULT_FIELDTYPE. a field type is used to articulate the desired options (namely pointValues, docValues, stored). Legacy numerics is configurable this way too.
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Method Details
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newInstance
public static PointVectorStrategy newInstance(org.locationtech.spatial4j.context.SpatialContext ctx, String fieldNamePrefix) Create a newPointVectorStrategyinstance that usesDoublePointandDoublePoint.newRangeQuery(java.lang.String, double, double) -
createIndexableFields
Description copied from class:SpatialStrategyReturns the IndexableField(s) from theshapethat are to be added to theDocument. These fields are expected to be marked as indexed and not stored.Note: If you want to store the shape as a string for retrieval in search results, you could add it like this:
document.add(new StoredField(fieldName,ctx.toString(shape)));
The particular string representation used doesn't matter to the Strategy since it doesn't use it.- Specified by:
createIndexableFieldsin classSpatialStrategy- Returns:
- Not null nor will it have null elements.
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createIndexableFields
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makeDistanceValueSource
public DoubleValuesSource makeDistanceValueSource(org.locationtech.spatial4j.shape.Point queryPoint, double multiplier) Description copied from class:SpatialStrategyMake a ValueSource returning the distance between the center of the indexed shape andqueryPoint. If there are multiple indexed shapes then the closest one is chosen. The result is multiplied bymultiplier, which conveniently is used to get the desired units.- Specified by:
makeDistanceValueSourcein classSpatialStrategy
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makeQuery
Description copied from class:SpatialStrategyMake a Query based principally onSpatialOperationandShapefrom the suppliedargs. It should be constant scoring of 1.- Specified by:
makeQueryin classSpatialStrategy
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