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)

Field Summary

(package private) int	attr
(package private) double	impurity
(package private) double	n
(package private) double	nl
(package private) double	nr
(package private) int	order
(package private) double	s2l
(package private) double	s2r
(package private) double	sd
(package private) double	sdl
(package private) double	sdr
(package private) double	sl
(package private) double	sr
(package private) double	va
(package private) double	vl
(package private) double	vr

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

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

n

double n

attr

int attr

nl

double nl

nr

double nr

sl

double sl

sr

double sr

s2l

double s2l

s2r

double s2r

sdl

double sdl

sdr

double sdr

vl

double vl

vr

double vr

sd

double sd

va

double va

impurity

double impurity

order

int order

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

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