Package elki.clustering.em

Class KDTreeEM.KDTree

java.lang.Object

elki.clustering.em.KDTreeEM.KDTree

Enclosing class:

KDTreeEM

static class KDTreeEM.KDTree
extends java.lang.Object

KDTree class with the statistics needed for EM clustering.

Author:

Robert Gehde

Field Summary

Fields

Modifier and Type	Field	Description
(package private) double[]	halfwidth	Half width of the rectangle.
(package private) int	left	Interval in sorted list
(package private) KDTreeEM.KDTree	leftChild	Child nodes:
(package private) double[]	midpoint	Middle point of bounding box
(package private) int	right	Interval in sorted list
(package private) KDTreeEM.KDTree	rightChild	Child nodes:
(package private) double[]	sum	Sum of contained vectors
(package private) double[][]	sumSq	Sum over all squared elements (x^T * x), needed for covariance calculation

Constructor Summary

Constructors

Constructor	Description
KDTree(Relation<? extends NumberVector> relation, ArrayModifiableDBIDs sorted, int left, int right, double[] dimWidth, double mbw)	Constructor for a KDTree with statistics needed for KDTreeEM calculation.

Method Summary

Modifier and Type	Method	Description
private void	aggregateStats(Relation<? extends NumberVector> relation, DBIDArrayIter iter, int dim)	Aggregate the statistics for a leaf node.
private void	computeBoundingBox(Relation<? extends NumberVector> relation, DBIDArrayIter iter)	Compute the bounding box.

Methods inherited from class java.lang.Object

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

Field Detail

leftChild

KDTreeEM.KDTree leftChild

Child nodes:

rightChild

KDTreeEM.KDTree rightChild

Child nodes:

left

int left

Interval in sorted list

right

int right

Interval in sorted list

sum

double[] sum

Sum of contained vectors

sumSq

double[][] sumSq

Sum over all squared elements (x^T * x), needed for covariance calculation

midpoint

double[] midpoint

Middle point of bounding box

halfwidth

double[] halfwidth

Half width of the rectangle.

Constructor Detail

KDTree

public KDTree(Relation<? extends NumberVector> relation,
              ArrayModifiableDBIDs sorted,
              int left,
              int right,
              double[] dimWidth,
              double mbw)

Constructor for a KDTree with statistics needed for KDTreeEM calculation. Uses points between the indices left and right for calculation

Parameters:

relation - datapoints for the construction

sorted - sorted id array

left - leftmost datapoint used for construction

right - rightmost datapoint used for construction

dimWidth - Array containing the width of all dimensions on the complete dataset

mbw - factor when to stop construction. Stop if splitdimwidth < mbw * dimwidth[splitdim]

Method Detail

computeBoundingBox

private void computeBoundingBox(Relation<? extends NumberVector> relation,
                                DBIDArrayIter iter)

Compute the bounding box.

Parameters:

relation - Data relation

iter - Iterator

aggregateStats

private void aggregateStats(Relation<? extends NumberVector> relation,
                            DBIDArrayIter iter,
                            int dim)

Aggregate the statistics for a leaf node.

Parameters:

relation - Data relation

iter - Iterator

dim - Dimensionality