Class KDTreeNode

  • All Implemented Interfaces:
    Serializable

    public class KDTreeNode
    extends Object
    implements Serializable
    A class representing a KDTree node. A node does not explicitly store the instances that it contains. Instead, it only stores the start and end index of a portion in a master index array. Each node is assigned a portion in the master index array that stores the indices of the instances that the node contains. Every time a node is split by the KDTree's contruction method, the instances of its left child are moved to the left and the instances of its right child are moved to the right, in the portion of the master index array belonging to the node. The start and end index in each of its children are then set accordingly within that portion so that each have their own portion which contains their instances. P.S.: The master index array is only stored in KDTree class.
    Version:
    $Revision: 8034 $
    Author:
    Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz)
    See Also:
    Serialized Form
    • Field Summary

      Fields 
      Modifier and Type Field Description
      int m_End
      The end index of the portion of the master index array, which stores indices of the instances/points the node contains.
      KDTreeNode m_Left
      left subtree; contains instances with smaller or equal to split value.
      int m_NodeNumber
      node number (only for debug).
      double[][] m_NodeRanges
      lowest and highest value and width (= high - low) for each dimension.
      double[][] m_NodesRectBounds
      The lo and high bounds of the hyper rectangle described by the node.
      KDTreeNode m_Right
      right subtree; contains instances with larger than split value.
      int m_SplitDim
      attribute to split on.
      double m_SplitValue
      value to split on.
      int m_Start
      The start index of the portion of the master index array, which stores the indices of the instances/points the node contains.
    • Constructor Summary

      Constructors 
      Constructor Description
      KDTreeNode()
      Constructor.
      KDTreeNode​(int nodeNum, int startidx, int endidx, double[][] nodeRanges)
      Constructor.
      KDTreeNode​(int nodeNum, int startidx, int endidx, double[][] nodeRanges, double[][] rectBounds)  
    • Field Detail

      • m_NodeNumber

        public int m_NodeNumber
        node number (only for debug).
      • m_Left

        public KDTreeNode m_Left
        left subtree; contains instances with smaller or equal to split value.
      • m_Right

        public KDTreeNode m_Right
        right subtree; contains instances with larger than split value.
      • m_SplitValue

        public double m_SplitValue
        value to split on.
      • m_SplitDim

        public int m_SplitDim
        attribute to split on.
      • m_NodeRanges

        public double[][] m_NodeRanges
        lowest and highest value and width (= high - low) for each dimension.
      • m_NodesRectBounds

        public double[][] m_NodesRectBounds
        The lo and high bounds of the hyper rectangle described by the node.
      • m_Start

        public int m_Start
        The start index of the portion of the master index array, which stores the indices of the instances/points the node contains.
      • m_End

        public int m_End
        The end index of the portion of the master index array, which stores indices of the instances/points the node contains.
    • Constructor Detail

      • KDTreeNode

        public KDTreeNode()
        Constructor.
      • KDTreeNode

        public KDTreeNode​(int nodeNum,
                          int startidx,
                          int endidx,
                          double[][] nodeRanges)
        Constructor.
        Parameters:
        nodeNum - The node number/id.
        startidx - The start index of node's portion in master index array.
        endidx - The start index of node's portion in master index array.
        nodeRanges - The attribute ranges of the Instances/points contained in this node.
      • KDTreeNode

        public KDTreeNode​(int nodeNum,
                          int startidx,
                          int endidx,
                          double[][] nodeRanges,
                          double[][] rectBounds)
        Parameters:
        nodeNum - The node number/id.
        startidx - The start index of node's portion in master index array.
        endidx - The start index of node's portion in master index array.
        nodeRanges - The attribute ranges of the Instances/points contained in this node.
        rectBounds - The range of the rectangular region in the point space that this node represents (points inside this rectangular region can have different range).
    • Method Detail

      • getSplitDim

        public int getSplitDim()
        Gets the splitting dimension.
        Returns:
        splitting dimension
      • getSplitValue

        public double getSplitValue()
        Gets the splitting value.
        Returns:
        splitting value
      • isALeaf

        public boolean isALeaf()
        Checks if node is a leaf.
        Returns:
        true if it is a leaf
      • numInstances

        public int numInstances()
        Returns the number of Instances in the rectangular region defined by this node.
        Returns:
        The number of instances in this KDTreeNode.