weka.classifiers.trees.ht

## Class HNode

- java.lang.Object
- - weka.classifiers.trees.ht.HNode

- All Implemented Interfaces:
    java.io.Serializable
  Direct Known Subclasses:
    LeafNode, SplitNode

      public abstract class HNode
      extends java.lang.Object
      implements java.io.Serializable

  Abstract base class for nodes in a Hoeffding tree
  Author:
    Richard Kirkby (rkirkby@cs.waikato.ac.nz), Mark Hall (mhall{[at]}pentaho{[dot]}com)
  See Also:
    Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `java.util.Map<java.lang.String,WeightMass>` | `m_classDistribution` Class distribution at this node

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `HNode()` Construct a new HNode
    `HNode(java.util.Map<java.lang.String,WeightMass> classDistrib)` Construct a new HNode with the supplied class distribution

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `classDistributionIsPure()` Returns true if the class distribution is pure
    `double[]` | `getDistribution(Instance inst, Attribute classAtt)` Return a class probability distribution computed from the frequency counts at this node
    `void` | `graphTree(java.lang.StringBuffer text)`
    `int` | `installNodeNums(int nodeNum)`
    `boolean` | `isLeaf()` Returns true if this is a leaf
    `LeafNode` | `leafForInstance(Instance inst, SplitNode parent, java.lang.String parentBranch)` Return the leaf that the supplied instance ends up at
    `int` | `numEntriesInClassDistribution()` The size of the class distribution
    `java.lang.String` | `toString(boolean printLeaf)` Print a textual description of the tree
    `double` | `totalWeight()` Return the total weight of instances seen at this node
    `void` | `updateDistribution(Instance inst)` Update the class frequency distribution with the supplied instance
    `abstract void` | `updateNode(Instance inst)` Update the node with the supplied instance

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### m_classDistribution

          public java.util.Map<java.lang.String,WeightMass> m_classDistribution

      Class distribution at this node

  - ### Constructor Detail

    - #### HNode

          public HNode()

      Construct a new HNode

    - #### HNode

          public HNode(java.util.Map<java.lang.String,WeightMass> classDistrib)

      Construct a new HNode with the supplied class distribution
      Parameters:
        `classDistrib` -

  - ### Method Detail

    - #### isLeaf

          public boolean isLeaf()

      Returns true if this is a leaf
      Returns:

    - #### numEntriesInClassDistribution

          public int numEntriesInClassDistribution()

      The size of the class distribution
      Returns:
        the number of entries in the class distribution

    - #### classDistributionIsPure

          public boolean classDistributionIsPure()

      Returns true if the class distribution is pure
      Returns:
        true if the class distribution is pure

    - #### updateDistribution

          public void updateDistribution(Instance inst)

      Update the class frequency distribution with the supplied instance
      Parameters:
        `inst` - the instance to update with

    - #### getDistribution

          public double[] getDistribution(Instance inst,
                                 Attribute classAtt)
                                   throws java.lang.Exception

      Return a class probability distribution computed from the frequency counts at this node
      Parameters:
        `inst` - the instance to get a prediction for
        `classAtt` - the class attribute
      Returns:
        a class probability distribution
      Throws:
        `java.lang.Exception` - if a problem occurs

    - #### installNodeNums

          public int installNodeNums(int nodeNum)

    - #### graphTree

          public void graphTree(java.lang.StringBuffer text)

    - #### toString

          public java.lang.String toString(boolean printLeaf)

      Print a textual description of the tree
      Parameters:
        `printLeaf` - true if leaf models (NB, NB adaptive) should be output
      Returns:
        a textual description of the tree

    - #### totalWeight

          public double totalWeight()

      Return the total weight of instances seen at this node
      Returns:
        the total weight of instances seen at this node

    - #### leafForInstance

          public LeafNode leafForInstance(Instance inst,
                                 SplitNode parent,
                                 java.lang.String parentBranch)

      Return the leaf that the supplied instance ends up at
      Parameters:
        `inst` - the instance to find the leaf for
        `parent` - the parent node
        `parentBranch` - the parent branch
      Returns:
        the leaf that the supplied instance ends up at

    - #### updateNode

          public abstract void updateNode(Instance inst)
                                   throws java.lang.Exception

      Update the node with the supplied instance
      Parameters:
        `inst` - the instance to update with
      Throws:
        `java.lang.Exception` - if a problem occurs