org.apache.ignite.ml.knn.utils.indices

Class BallTreeSpatialIndex<L>

java.lang.Object

org.apache.ignite.ml.knn.utils.indices.BallTreeSpatialIndex<L>

Type Parameters:

L - Label type.

All Implemented Interfaces:

AutoCloseable, SpatialIndex<L>

public class BallTreeSpatialIndex<L>
extends Object
implements SpatialIndex<L>

Ball tree based implementation of SpatialIndex. Asymptotic runtime complexity of finding k closest elements is O(log(n)*k), but it degrades on high dimensional data.

Constructor Summary

Constructors

Constructor and Description
BallTreeSpatialIndex(List<LabeledVector<L>> data, DistanceMeasure distanceMeasure) Constructs a new instance of Ball tree spatial index.

Method Summary

Modifier and Type	Method and Description
List<LabeledVector<L>>	findKClosest(int k, Vector pnt) Finds k closest elements to the specified point.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ignite.ml.knn.utils.indices.SpatialIndex

close

Constructor Detail

BallTreeSpatialIndex

public BallTreeSpatialIndex(List<LabeledVector<L>> data,
                            DistanceMeasure distanceMeasure)

Constructs a new instance of Ball tree spatial index.

Parameters:

data - Data.

distanceMeasure - Distance measure.

Method Detail

findKClosest

public List<LabeledVector<L>> findKClosest(int k,
                                           Vector pnt)

Finds k closest elements to the specified point.

Specified by:

findKClosest in interface SpatialIndex<L>

Parameters:

k - Number of elements to be returned.

pnt - Point to be used to calculate distance to other points.

Returns:

An array of the k closest elements to the specified point.