Package nz.org.riskscape.engine.geo

Class NearestNeighbourIndex

java.lang.Object
nz.org.riskscape.engine.geo.NearestNeighbourIndex
public class NearestNeighbourIndex extends Object

An index that when queried will return the nearest neighbour should one exist within a max distance.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    NearestNeighbourIndex.Visitor
     

  • Method Summary

    Modifier and Type
    Method
    Description
    org.locationtech.jts.geom.Envelope
    getEnvelope()
     
    double
    getMaxDistanceInCrsUnits()
     
    final void
    insert(nz.org.riskscape.engine.Tuple item)
    Insert a Tuple into the index.
    static NearestNeighbourIndex
    metricMaxDistance(nz.org.riskscape.engine.types.Struct.StructMember geometryMember, nz.org.riskscape.engine.SRIDSet sridSet, org.geotools.api.referencing.crs.CoordinateReferenceSystem crs, double maxDistance)
    Create a nearest neighbour index with the given max distance (in metres).
    nz.org.riskscape.engine.Tuple
    query(org.locationtech.jts.geom.Coordinate coordinate)
    Find the indexed entry that is closest to coordinate but still within maxDistanceInCrsUnits.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • metricMaxDistance

      public static NearestNeighbourIndex metricMaxDistance(nz.org.riskscape.engine.types.Struct.StructMember geometryMember, nz.org.riskscape.engine.SRIDSet sridSet, org.geotools.api.referencing.crs.CoordinateReferenceSystem crs, double maxDistance)

      Create a nearest neighbour index with the given max distance (in metres).

      Parameters:
      geometryMember - the geometry member that contains the geometry we are indexing from given tuples
      sridSet - an srid set to use for asserting that the geometry we end up indexing is in the correct CRS.
      crs - the coordinate reference system this index will be in. So far, this is not persisted with the index, but is used to derive a metric max distance and an expectedSrid
      maxDistance - the max distance (in metres ) that the match must be within. Note that if the CRS is not based on a metric grid, this will be an approximation.

    • insert

      public final void insert(nz.org.riskscape.engine.Tuple item)

      Insert a Tuple into the index. The tuple will be indexed by to the geometry accessed with geometryMemberAccessor.

      Parameters:
      item - to add to index

    • getEnvelope

      public org.locationtech.jts.geom.Envelope getEnvelope()
      Returns:
      the envelope that the index may provide matches within.

    • query

      public nz.org.riskscape.engine.Tuple query(org.locationtech.jts.geom.Coordinate coordinate)

      Find the indexed entry that is closest to coordinate but still within maxDistanceInCrsUnits.

      Parameters:
      coordinate - where to query the index
      Returns:
      closest entry to coordinate, or null if there no entry is found with maxDistance.

    • getMaxDistanceInCrsUnits

      public double getMaxDistanceInCrsUnits()