weka.classifiers.trees.m5
Class Impurity

java.lang.Object
  |
  +--weka.classifiers.trees.m5.Impurity

public final class Impurity

extends java.lang.Object

Class for handling the impurity values when spliting the instances

Version:

$Revision: 1.6 $

Author:

Yong Wang (yongwang@cs.waikato.ac.nz)

Constructor Summary

Impurity(int partition, int attribute, Instances inst, int k)
Constructs an Impurity object containing the impurity values of partitioning the instances using an attribute

Method Summary

void	incremental(double value, int type) Incrementally computes the impurirty values
java.lang.String	toString() Converts an Impurity object to a string

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Impurity

public Impurity(int partition,
                int attribute,
                Instances inst,
                int k)

Constructs an Impurity object containing the impurity values of partitioning the instances using an attribute

Parameters:

partition - the index of the last instance in the left subset

attribute - the attribute used in partitioning

inst - instances

k - the order of the impurity; =1, the variance; =2, the stardard deviation; =k, the k-th order root of the variance

Method Detail

toString

public final java.lang.String toString()

Converts an Impurity object to a string

Overrides:

toString in class java.lang.Object

Returns:

the converted string

incremental

public final void incremental(double value,
                              int type)

Incrementally computes the impurirty values

Parameters:

value - the incremental value

type - if type=1, value will be added to the left subset; type=-1, to the right subset; type=0, initializes