Class WithinPrefixTreeFilter

Finds docs where its indexed shape is IsWithin the query shape. It works by looking at cells outside of the query shape to ensure documents there are excluded. By default, it will examine all cells, and it's fairly slow. If you know that the indexed shapes are never comprised of multiple disjoint parts (which also means it is not multi-valued), then you can pass SpatialPrefixTree.GetDistanceForLevel(maxLevels) as the queryBuffer constructor parameter to minimally look this distance beyond the query shape's edge. Even if the indexed shapes are sometimes comprised of multiple disjoint parts, you might want to use this option with a large buffer as a faster approximation with minimal false-positives.

This is a Lucene.NET EXPERIMENTAL API, use at your own risk
Inheritance
System.Object
Filter
AbstractPrefixTreeFilter
AbstractVisitingPrefixTreeFilter
WithinPrefixTreeFilter
Inherited Members
System.Object.Equals(System.Object, System.Object)
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Lucene.Net.Spatial.Prefix
Assembly: Lucene.Net.Spatial.dll
Syntax
public class WithinPrefixTreeFilter : AbstractVisitingPrefixTreeFilter

Constructors

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WithinPrefixTreeFilter(IShape, String, SpatialPrefixTree, Int32, Int32, Double)

See AbstractVisitingPrefixTreeFilter(IShape, String, SpatialPrefixTree, Int32, Int32). queryBuffer is the (minimum) distance beyond the query shape edge where non-matching documents are looked for so they can be excluded. If -1 is used then the whole world is examined (a good default for correctness).

Declaration
public WithinPrefixTreeFilter(IShape queryShape, string fieldName, SpatialPrefixTree grid, int detailLevel, int prefixGridScanLevel, double queryBuffer)
Parameters
Type Name Description
Spatial4n.Core.Shapes.IShape queryShape
System.String fieldName
SpatialPrefixTree grid
System.Int32 detailLevel
System.Int32 prefixGridScanLevel
System.Double queryBuffer

Methods

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BufferShape(IShape, Double)

Returns a new shape that is larger than shape by at distErr.

Declaration
protected virtual IShape BufferShape(IShape shape, double distErr)
Parameters
Type Name Description
Spatial4n.Core.Shapes.IShape shape
System.Double distErr
Returns
Type Description
Spatial4n.Core.Shapes.IShape
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GetDocIdSet(AtomicReaderContext, IBits)

Declaration
public override DocIdSet GetDocIdSet(AtomicReaderContext context, IBits acceptDocs)
Parameters
Type Name Description
AtomicReaderContext context
IBits acceptDocs
Returns
Type Description
DocIdSet
Overrides
Exceptions
Type Condition
System.IO.IOException