com.savarese.spatial
Class NearestNeighbors<Coord extends java.lang.Number & java.lang.Comparable<? super Coord>,P extends Point<Coord>,V>

java.lang.Object
  com.savarese.spatial.NearestNeighbors<Coord,P,V>

public class NearestNeighbors<Coord extends java.lang.Number & java.lang.Comparable<? super Coord>,P extends Point<Coord>,V>
extends java.lang.Object

NearestNeighbors implements an algorithm for finding the k-nearest neighbors to a query point within the set of points contained by a KDTree instance. The algorithm can be specialized with a custom distance-finding function by passing a Distance instance to its constructor.

Nested Class Summary

static interface

NearestNeighbors.Entry<Coord extends java.lang.Number & java.lang.Comparable<? super Coord>,P extends Point<Coord>,V> The Entry interface makes accessible the results of a NearestNeighbors search.

Constructor Summary

NearestNeighbors()
Constructs a NearestNeighbors instance using a EuclideanDistance instance to calculate distances between points.

NearestNeighbors(Distance<Coord,P> distance)
Constructs a new NearestNeighbors instance, using the specified distance-finding functor to calculate distances during searches.

Method Summary

NearestNeighbors.Entry<Coord,P,V>[]	get(KDTree<Coord,P,V> tree, P queryPoint, int numNeighbors) Same as get(tree, queryPoint, numNeighbors, true).
NearestNeighbors.Entry<Coord,P,V>[]	get(KDTree<Coord,P,V> tree, P queryPoint, int numNeighbors, boolean omitQueryPoint) Finds the k-nearest neighbors to a query point withina KDTree instance.
void	setDistance(Distance<Coord,P> distance) Sets the distance-finding functor used to calculate distances during searches.

Methods inherited from class java.lang.Object

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

Constructor Detail

NearestNeighbors

public NearestNeighbors(Distance<Coord,P> distance)

Constructs a new NearestNeighbors instance, using the specified distance-finding functor to calculate distances during searches.

Parameters:

distance - A distance-finding functor implementing the Distance interface.

NearestNeighbors

public NearestNeighbors()

Constructs a NearestNeighbors instance using a EuclideanDistance instance to calculate distances between points.

Method Detail

setDistance

public void setDistance(Distance<Coord,P> distance)

Sets the distance-finding functor used to calculate distances during searches.

Parameters:

distance - The distance-finding functor to use for distance calculations.

get

public NearestNeighbors.Entry<Coord,P,V>[] get(KDTree<Coord,P,V> tree,
                                               P queryPoint,
                                               int numNeighbors,
                                               boolean omitQueryPoint)

Finds the k-nearest neighbors to a query point withina KDTree instance. The neighbors are returned as an array of NearestNeighbors.Entry instances, sorted from nearest to farthest.

Parameters:

tree - The KDTree to search.

queryPoint - The query point.

numNeighbors - The number of nearest neighbors to find. This should be a positive value. Non-positive values result in no neighbors being found.

omitQueryPoint - If true, point-value mappings at a distance of zero are omitted from the result. If false, mappings at a distance of zero are included.

Returns:

An array containing the nearest neighbors and their distances sorted by least distance to greatest distance. If no neighbors are found, the array will have a length of zero.

get

public NearestNeighbors.Entry<Coord,P,V>[] get(KDTree<Coord,P,V> tree,
                                               P queryPoint,
                                               int numNeighbors)

Same as get(tree, queryPoint, numNeighbors, true).