de.lmu.ifi.dbs.elki.index.tree.spatial
Class BulkSplit<N extends SpatialObject>

java.lang.Object
  de.lmu.ifi.dbs.elki.index.tree.spatial.BulkSplit<N>

Type Parameters:

N - object type

public class BulkSplit<N extends SpatialObject>
extends Object

Encapsulates the required parameters for a bulk split of a spatial index.

Author:

Elke Achtert

Nested Class Summary

static class

BulkSplit.Strategy Available strategies for bulk loading.

Field Summary

private static Logging

logger

Constructor Summary

BulkSplit()
Constructor

Method Summary

private int	chooseBulkSplitPoint(int numEntries, int minEntries, int maxEntries) Computes and returns the best split point.
private int	chooseMaximalExtendedSplitAxis(List<N> objects) Computes and returns the best split axis.
private List<List<N>>	maximalExtensionPartition(List<N> spatialObjects, int minEntries, int maxEntries) Partitions the specified feature vectors where the split axes are the dimensions with maximum extension
List<List<N>>	partition(List<N> spatialObjects, int minEntries, int maxEntries, BulkSplit.Strategy strategy) Partitions the specified feature vectors according to the chosen strategy.
private List<List<N>>	zValuePartition(List<N> spatialObjects, int minEntries, int maxEntries) Partitions the spatial objects according to their z-values.

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static Logging logger

Constructor Detail

BulkSplit

public BulkSplit()

Constructor

Method Detail

partition

public List<List<N>> partition(List<N> spatialObjects,
                               int minEntries,
                               int maxEntries,
                               BulkSplit.Strategy strategy)

Partitions the specified feature vectors according to the chosen strategy.

Parameters:

spatialObjects - the spatial objects to be partitioned

minEntries - the minimum number of entries in a partition

maxEntries - the maximum number of entries in a partition

strategy - the bulk load strategy

Returns:

the partition of the specified spatial objects according to the chosen strategy

maximalExtensionPartition

private List<List<N>> maximalExtensionPartition(List<N> spatialObjects,
                                                int minEntries,
                                                int maxEntries)

Partitions the specified feature vectors where the split axes are the dimensions with maximum extension

Parameters:

spatialObjects - the spatial objects to be partitioned

minEntries - the minimum number of entries in a partition

maxEntries - the maximum number of entries in a partition

Returns:

the partition of the specified spatial objects

zValuePartition

private List<List<N>> zValuePartition(List<N> spatialObjects,
                                      int minEntries,
                                      int maxEntries)

Partitions the spatial objects according to their z-values.

Parameters:

spatialObjects - the spatial objects to be partitioned

minEntries - the minimum number of entries in a partition

maxEntries - the maximum number of entries in a partition

Returns:

A partition of the spatial objects according to their z-values

chooseMaximalExtendedSplitAxis

private int chooseMaximalExtendedSplitAxis(List<N> objects)

Computes and returns the best split axis. The best split axis is the split axes with the maximal extension.

Parameters:

objects - the spatial objects to be splitted

Returns:

the best split axis

chooseBulkSplitPoint

private int chooseBulkSplitPoint(int numEntries,
                                 int minEntries,
                                 int maxEntries)

Computes and returns the best split point.

Parameters:

numEntries - the number of entries to be split

minEntries - the number of minimum entries in the node to be split

maxEntries - number of maximum entries in the node to be split

Returns:

the best split point