Class MedianOfWidestDimension
java.lang.Object
weka.core.neighboursearch.balltrees.BallSplitter
weka.core.neighboursearch.balltrees.MedianOfWidestDimension
- All Implemented Interfaces:
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: 10203 $
- Author:
- Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz)
- See Also:
-
Constructor Summary
ConstructorDescriptionConstructor.MedianOfWidestDimension
(int[] instList, Instances insts, EuclideanDistance e) Constructor. -
Method Summary
Modifier and TypeMethodDescriptionboolean
Whether we are normalizing the widths(ranges) of the dimensions (attributes) or not.String[]
Gets the current settings.Returns the revision string.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.Returns a string describing this nearest neighbour search algorithm.Returns an enumeration describing the available options.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
(String[] options) Parses a given list of options.void
Splits a ball into two.Methods inherited from class weka.core.neighboursearch.balltrees.BallSplitter
setEuclideanDistanceFunction, setInstanceList, setInstances
-
Constructor Details
-
MedianOfWidestDimension
public MedianOfWidestDimension()Constructor. -
MedianOfWidestDimension
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.
-
-
Method Details
-
globalInfo
Returns a string describing this nearest neighbour search algorithm.- Returns:
- a description of the algorithm for displaying in the explorer/experimenter gui
-
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
-
splitNode
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:
Exception
- If there is some problem in splitting the given node.
-
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
-
normalizeDimWidthsTipText
Returns the tip text for this property.- Returns:
- tip text for this property suitable for displaying in the explorer/experimenter gui
-
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.
-
getNormalizeDimWidths
public boolean getNormalizeDimWidths()Whether we are normalizing the widths(ranges) of the dimensions (attributes) or not.- Returns:
- true if widths are being normalized.
-
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.
-
setOptions
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:
Exception
- if an option is not supported
-
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.
-
getRevision
Returns the revision string.- Specified by:
getRevision
in interfaceRevisionHandler
- Overrides:
getRevision
in classBallSplitter
- Returns:
- the revision
-