RandomSplit (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

java.lang.Object
- elki.index.tree.metrical.mtreevariants.strategies.split.AbstractMTreeSplit<E,N>
- - 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

Field Summary

Fields
Modifier and Type Field Description

private java.util.Random random
Random generator.
- Fields inherited from class elki.index.tree.metrical.mtreevariants.strategies.split.AbstractMTreeSplit
  distributor

Constructor Summary

Constructors
Constructor Description

RandomSplit(DistributionStrategy distributor, RandomFactory rnd)
Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	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 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