Class MedianOfWidestDimension
- java.lang.Object
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- weka.core.neighboursearch.balltrees.BallSplitter
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- weka.core.neighboursearch.balltrees.MedianOfWidestDimension
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- All Implemented Interfaces:
java.io.Serializable
,OptionHandler
,RevisionHandler
,TechnicalInformationHandler
public class MedianOfWidestDimension extends BallSplitter implements OptionHandler, TechnicalInformationHandler
Class that splits a BallNode of a ball tree based on the median value of the widest dimension of the points in the ball. It essentially implements Omohundro's KD construction algorithm. 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:-N Normalize dimensions' widths.
- Version:
- $Revision: 1.2 $
- Author:
- Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz)
- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description MedianOfWidestDimension()
Constructor.MedianOfWidestDimension(int[] instList, Instances insts, EuclideanDistance e)
Constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
getNormalizeDimWidths()
Whether we are normalizing the widths(ranges) of the dimensions (attributes) or not.java.lang.String[]
getOptions()
Gets the current settings.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
listOptions()
Returns an enumeration describing the available options.java.lang.String
normalizeDimWidthsTipText()
Returns the tip text for this property.int
select(int attIdx, int[] indices, int left, int right, int k)
Implements computation of the kth-smallest element according to Manber's "Introduction to Algorithms".void
setNormalizeDimWidths(boolean normalize)
Should we normalize the widths(ranges) of the dimensions (attributes) before selecting the widest one.void
setOptions(java.lang.String[] options)
Parses a given list of options.void
splitNode(BallNode node, int numNodesCreated)
Splits a ball into two.-
Methods inherited from class weka.core.neighboursearch.balltrees.BallSplitter
setEuclideanDistanceFunction, setInstanceList, setInstances
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Constructor Detail
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MedianOfWidestDimension
public MedianOfWidestDimension()
Constructor.
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MedianOfWidestDimension
public MedianOfWidestDimension(int[] instList, Instances insts, EuclideanDistance e)
Constructor.- Parameters:
instList
- The master index array.insts
- The instances on which the tree is (or is to be) built.e
- The Euclidean distance function to use for splitting.
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Method Detail
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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
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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 interfaceTechnicalInformationHandler
- Returns:
- the technical information about this class
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splitNode
public void splitNode(BallNode node, int numNodesCreated) throws java.lang.Exception
Splits a ball into two.- Specified by:
splitNode
in classBallSplitter
- Parameters:
node
- The node to split.numNodesCreated
- The number of nodes that so far have been created for the tree, so that the newly created nodes are assigned correct/meaningful node numbers/ids.- Throws:
java.lang.Exception
- If there is some problem in splitting the given node.
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select
public int select(int attIdx, int[] indices, int left, int right, int k)
Implements computation of the kth-smallest element according to Manber's "Introduction to Algorithms".- Parameters:
attIdx
- The dimension/attribute of the instances in which to find the kth-smallest element.indices
- The master index array containing indices of the instances.left
- The begining index of the portion of the master index array in which to find the kth-smallest element.right
- The end index of the portion of the master index array in which to find the kth-smallest element.k
- The value of k- Returns:
- The index of the kth-smallest element
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normalizeDimWidthsTipText
public java.lang.String normalizeDimWidthsTipText()
Returns the tip text for this property.- Returns:
- tip text for this property suitable for displaying in the explorer/experimenter gui
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setNormalizeDimWidths
public void setNormalizeDimWidths(boolean normalize)
Should we normalize the widths(ranges) of the dimensions (attributes) before selecting the widest one.- Parameters:
normalize
- Should be true if the widths are to be normalized.
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getNormalizeDimWidths
public boolean getNormalizeDimWidths()
Whether we are normalizing the widths(ranges) of the dimensions (attributes) or not.- Returns:
- true if widths are being normalized.
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listOptions
public java.util.Enumeration listOptions()
Returns an enumeration describing the available options.- Specified by:
listOptions
in interfaceOptionHandler
- Overrides:
listOptions
in classBallSplitter
- Returns:
- an enumeration of all the available options.
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setOptions
public void setOptions(java.lang.String[] options) throws java.lang.Exception
Parses a given list of options. Valid options are:-N Normalize dimensions' widths.
- Specified by:
setOptions
in interfaceOptionHandler
- Overrides:
setOptions
in classBallSplitter
- Parameters:
options
- the list of options as an array of strings- Throws:
java.lang.Exception
- if an option is not supported
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getOptions
public java.lang.String[] getOptions()
Gets the current settings.- Specified by:
getOptions
in interfaceOptionHandler
- Overrides:
getOptions
in classBallSplitter
- Returns:
- An array of strings suitable for passing to setOptions or to be displayed by a GenericObjectEditor.
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getRevision
public java.lang.String getRevision()
Returns the revision string.- Specified by:
getRevision
in interfaceRevisionHandler
- Overrides:
getRevision
in classBallSplitter
- Returns:
- the revision
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