weka.core.neighboursearch.balltrees

Class TopDownConstructor

java.lang.Object

weka.core.neighboursearch.balltrees.BallTreeConstructor

weka.core.neighboursearch.balltrees.TopDownConstructor

All Implemented Interfaces:

java.io.Serializable, OptionHandler, RevisionHandler, TechnicalInformationHandler

public class TopDownConstructor
extends BallTreeConstructor
implements TechnicalInformationHandler

The class implementing the TopDown construction method of ball trees. It further uses one of a number of different splitting methods to split a ball while constructing the tree top down.

For more information see also:

Stephen M. Omohundro (1989). Five Balltree Construction Algorithms.

BibTeX:

 @techreport{Omohundro1989,
    author = {Stephen M. Omohundro},
    institution = {International Computer Science Institute},
    month = {December},
    number = {TR-89-063},
    title = {Five Balltree Construction Algorithms},
    year = {1989}
 }
 

Valid options are:

 -S <classname and options>
  Ball splitting algorithm to use.
 

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected BallSplitter	m_Splitter The BallSplitter algorithm used by the TopDown BallTree constructor, if it is selected.

Fields inherited from class weka.core.neighboursearch.balltrees.BallTreeConstructor

m_DistanceFunction, m_FullyContainChildBalls, m_Instances, m_InstList, m_MaxDepth, m_MaxInstancesInLeaf, m_MaxRelLeafRadius, m_NumLeaves, m_NumNodes

Constructor Summary

Constructors

Constructor and Description
TopDownConstructor() Creates a new instance of TopDownConstructor.

Method Summary

Modifier and Type	Method and Description
int[]	addInstance(BallNode node, Instance inst) Adds an instance to the ball tree.
java.lang.String	ballSplitterTipText() Returns the tip text for this property.
BallNode	buildTree() Builds the ball tree top down.
BallSplitter	getBallSplitter() Returns the BallSplitter algorithm set that would be used by the TopDown BallTree constructor.
java.lang.String[]	getOptions() Gets the current settings of KDtree.
java.lang.String	getRevision() Returns the revision string.
TechnicalInformation	getTechnicalInformation() Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.
java.lang.String	globalInfo() Returns a string describing this nearest neighbour search algorithm.
java.util.Enumeration<Option>	listOptions() Returns an enumeration describing the available options.
protected void	processNodesAfterAddInstance(BallNode node) Post process method to correct the start and end indices of BallNodes on the right of the node where the instance was added.
void	setBallSplitter(BallSplitter splitter) Sets the ball splitting algorithm to be used by the TopDown constructor.
void	setOptions(java.lang.String[] options) Parses a given list of options
protected void	splitNodes(BallNode node, int depth, double rootRadius) Recursively splits nodes of a ball tree until <=m_MaxInstancesInLeaf instances remain in a node.

Methods inherited from class weka.core.neighboursearch.balltrees.BallTreeConstructor

containChildBallsTipText, getContainChildBalls, getMaxDepth, getMaxInstancesInLeaf, getMaxRelativeLeafRadius, getNumLeaves, getNumNodes, maxInstancesInLeafTipText, maxRelativeLeafRadiusTipText, setContainChildBalls, setEuclideanDistanceFunction, setInstanceList, setInstances, setMaxInstancesInLeaf, setMaxRelativeLeafRadius

Methods inherited from class java.lang.Object

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

Field Detail

m_Splitter

protected BallSplitter m_Splitter

The BallSplitter algorithm used by the TopDown BallTree constructor, if it is selected.

Constructor Detail

TopDownConstructor

public TopDownConstructor()

Creates a new instance of TopDownConstructor.

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this nearest neighbour search algorithm.

Returns:

a description of the algorithm for displaying in the explorer/experimenter gui

getTechnicalInformation

public TechnicalInformation getTechnicalInformation()

Returns an instance of a TechnicalInformation object, containing detailed information about the technical background of this class, e.g., paper reference or book this class is based on.

Specified by:

getTechnicalInformation in interface TechnicalInformationHandler

Returns:

the technical information about this class

buildTree

public BallNode buildTree()
                   throws java.lang.Exception

Builds the ball tree top down.

Specified by:

buildTree in class BallTreeConstructor

Returns:

The root node of the tree.

Throws:

java.lang.Exception - If there is problem building the tree.

splitNodes

protected void splitNodes(BallNode node,
                          int depth,
                          double rootRadius)
                   throws java.lang.Exception

Recursively splits nodes of a ball tree until <=m_MaxInstancesInLeaf instances remain in a node.

Parameters:

node - The node to split.

depth - The depth of this node in the tree, so that m_MaxDepth is correctly updated.

rootRadius - The smallest ball enclosing all the data points.

Throws:

java.lang.Exception - If there is some problem in splitting.

addInstance

public int[] addInstance(BallNode node,
                         Instance inst)
                  throws java.lang.Exception

Adds an instance to the ball tree.

Specified by:

addInstance in class BallTreeConstructor

Parameters:

node - The root node of the tree.

inst - The instance to add to the tree.

Returns:

The new master index array after adding the instance.

Throws:

java.lang.Exception - If there is some problem adding the given instance to the tree.

processNodesAfterAddInstance

protected void processNodesAfterAddInstance(BallNode node)

Post process method to correct the start and end indices of BallNodes on the right of the node where the instance was added.

Parameters:

node - The node whose m_Start and m_End need to be updated.

ballSplitterTipText

public java.lang.String ballSplitterTipText()

Returns the tip text for this property.

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getBallSplitter

public BallSplitter getBallSplitter()

Returns the BallSplitter algorithm set that would be used by the TopDown BallTree constructor.

Returns:

The BallSplitter currently in use.

setBallSplitter

public void setBallSplitter(BallSplitter splitter)

Sets the ball splitting algorithm to be used by the TopDown constructor.

Parameters:

splitter - The BallSplitter to use.

listOptions

public java.util.Enumeration<Option> listOptions()

Returns an enumeration describing the available options.

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class BallTreeConstructor

Returns:

an enumeration of all the available options.

setOptions

public void setOptions(java.lang.String[] options)
                throws java.lang.Exception

Parses a given list of options. Valid options are:

 -S <classname and options>
  Ball splitting algorithm to use.
 

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class BallTreeConstructor

Parameters:

options - the list of options as an array of strings

Throws:

java.lang.Exception - if an option is not supported

getOptions

public java.lang.String[] getOptions()

Gets the current settings of KDtree.

Specified by:

getOptions in interface OptionHandler

Overrides:

getOptions in class BallTreeConstructor

Returns:

an array of strings suitable for passing to setOptions

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Overrides:

getRevision in class BallTreeConstructor

Returns:

the revision