Package elki.index.tree.metrical.vptree

Class VPTree.Builder

java.lang.Object

elki.index.tree.metrical.vptree.VPTree.Builder

Enclosing class:

VPTree<O>

private class VPTree.Builder
extends java.lang.Object

Build the VP-Tree

Author:

Erich Schubert

Field Summary

Fields

Modifier and Type	Field	Description
(package private) java.util.Random	rnd	Random generator
(package private) ModifiableDoubleDBIDList	scratch	Scratch space for organizing the elements
(package private) DoubleDBIDListMIter	scratchit	Scratch iterator

Constructor Summary

Constructors

Constructor	Description
Builder()	Constructor.

Method Summary

Modifier and Type	Method	Description
private VPTree.Node	buildTree(int left, int right)	Build the tree recursively
private double	calcMoment(DBIDRef p, DBIDs check, int size)	Calculate the 2nd moment to the median of the distances to p
private DBIDVar	chooseVantagePoint(int left, int right)	Find a vantage points in the DBIDs between left and right

Methods inherited from class java.lang.Object

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

Field Detail

scratch

ModifiableDoubleDBIDList scratch

Scratch space for organizing the elements

scratchit

DoubleDBIDListMIter scratchit

Scratch iterator

rnd

java.util.Random rnd

Random generator

Constructor Detail

Builder

public Builder()

Constructor.

Method Detail

buildTree

private VPTree.Node buildTree(int left,
                              int right)

Build the tree recursively

Parameters:

left - Left bound in scratch

right - Right bound in scratch

Returns:

new node

chooseVantagePoint

private DBIDVar chooseVantagePoint(int left,
                                   int right)

Find a vantage points in the DBIDs between left and right

Parameters:

left - Left bound in scratch

right - Right bound in scratch

Returns:

vantage point

calcMoment

private double calcMoment(DBIDRef p,
                          DBIDs check,
                          int size)

Calculate the 2nd moment to the median of the distances to p

Parameters:

p - DBID to calculate the moment for

check - points to check with

size - Maximum size to use

Returns:

second moment