de.lmu.ifi.dbs.elki.index.tree.metrical.mtreevariants.strategies.split

Class RandomSplit<E extends MTreeEntry,N extends AbstractMTreeNode<?,N,E>>

java.lang.Object

de.lmu.ifi.dbs.elki.index.tree.metrical.mtreevariants.strategies.split.AbstractMTreeSplit<E,N>

de.lmu.ifi.dbs.elki.index.tree.metrical.mtreevariants.strategies.split.RandomSplit<E,N>

Type Parameters:

E - the type of MTreeEntry used in the M-Tree

N - the type of AbstractMTreeNode used in the M-Tree

All Implemented Interfaces:

MTreeSplit<E,N>

@Reference(authors="P. Ciaccia, M. Patella, P. Zezula",
           title="M-tree: An Efficient Access Method for Similarity Search in Metric Spaces",
           booktitle="Proc. Int. Conf. Very Large Data Bases (VLDB\'97)",
           url="http://www.vldb.org/conf/1997/P426.PDF",
           bibkey="DBLP:conf/vldb/CiacciaPZ97")
public class RandomSplit<E extends MTreeEntry,N extends AbstractMTreeNode<?,N,E>>
extends AbstractMTreeSplit<E,N>

Encapsulates the required methods for a split of a node in an M-Tree. The routing objects are chosen according to the RANDOM strategy.

Note: only the routing objects are chosen at random, this is not a random assignment!

Reference:

P. Ciaccia, M. Patella, P. Zezula
M-tree: An Efficient Access Method for Similarity Search in Metric Spaces
In Proc. Int. Conf. Very Large Data Bases (VLDB'97)

Since:

0.2

Author:

Elke Achtert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RandomSplit.Parameterizer<E extends MTreeEntry,N extends AbstractMTreeNode<?,N,E>> Parameterization class.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Random	random Random generator.

Fields inherited from class de.lmu.ifi.dbs.elki.index.tree.metrical.mtreevariants.strategies.split.AbstractMTreeSplit

distributor

Constructor Summary

Constructors

Constructor and Description
RandomSplit(DistributionStrategy distributor, RandomFactory rnd) Constructor.

Method Summary

Modifier and Type	Method and Description
Assignments<E>	split(AbstractMTree<?,N,E,?> tree, N node) Selects two objects of the specified node to be promoted and stored into the parent node.

Methods inherited from class de.lmu.ifi.dbs.elki.index.tree.metrical.mtreevariants.strategies.split.AbstractMTreeSplit

computeDistanceMatrix

Methods inherited from class java.lang.Object

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

Field Detail

random

private java.util.Random random

Random generator.

Constructor Detail

RandomSplit

public RandomSplit(DistributionStrategy distributor,
                   RandomFactory rnd)

Constructor.

Parameters:

distributor - Distribution strategy

rnd - Random generator

Method Detail

split

public Assignments<E> split(AbstractMTree<?,N,E,?> tree,
                            N node)

Selects two objects of the specified node to be promoted and stored into the parent node. The m-RAD strategy considers all possible pairs of objects and, after partitioning the set of entries, promotes the pair of objects for which the sum of covering radiuses is minimum.

Parameters:

tree - Tree to use

node - the node to be split

Returns:

the assignments of this split