Package weka.core.neighboursearch.balltrees

Class BottomUpConstructor

  • All Implemented Interfaces:
    java.io.Serializable, OptionHandler, RevisionHandler, TechnicalInformationHandler
    public class BottomUpConstructor
extends BallTreeConstructor
implements TechnicalInformationHandler
    The class that constructs a ball tree bottom up.

    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 <value>
  Set maximum number of instances in a leaf node
  (default: 40)
     -R
  Set internal nodes' radius to the sum 
  of the child balls radii. So that it 
 contains the child balls.
    Version:
    $Revision: 1.3 $
    Author:
    Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz)
    See Also:
    Serialized Form

    • Constructor Detail

      • BottomUpConstructor

        public BottomUpConstructor()
        Creates a new instance of BottomUpConstructor.

    • 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 bottom up.
        Specified by:
        buildTree in class BallTreeConstructor
        Returns:
        The root node of the tree.
        Throws:
        java.lang.Exception - If there is problem building the tree.

      • 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 - Always as BottomUpConstructor does not allow addition of instances after batch construction.

      • calcPivot

        public Instance calcPivot​(weka.core.neighboursearch.balltrees.BottomUpConstructor.TempNode node1,
                          weka.core.neighboursearch.balltrees.BottomUpConstructor.TempNode node2,
                          Instances insts)
                   throws java.lang.Exception
        Calculates the centroid pivot of a node based on its two child nodes.
        Parameters:
        node1 - The first child node.
        node2 - The second child node.
        insts - The instance on which the tree is to be built.
        Returns:
        The centre/pivot of the node.
        Throws:
        java.lang.Exception - If there is some problem calculating the centre/pivot of the node.

      • calcRadius

        public double calcRadius​(weka.core.neighboursearch.balltrees.BottomUpConstructor.TempNode n1,
                         weka.core.neighboursearch.balltrees.BottomUpConstructor.TempNode n2)
                  throws java.lang.Exception
        Calculates the radius of a node based on its two child nodes.
        Parameters:
        n1 - The first child node.
        n2 - The second child node.
        Returns:
        The calculated radius of the the node.
        Throws:
        java.lang.Exception - If there is some problem in calculating the radius.