weka.classifiers.m5
Class Function

java.lang.Object
  |
  +--weka.classifiers.m5.Function

All Implemented Interfaces:

java.io.Serializable

public final class Function

extends java.lang.Object

implements java.io.Serializable

Class for handling a linear function.

Author:

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

See Also:

Serialized Form

Constructor Summary

Function()
Constructs a function of constant value

Function(Instances inst)
Constucts a function with all attributes except the class in the inst

Function(int attr)
Constructs a function with one attribute

Method Summary

static Function	combine(Function f1, Function f2) Constructs a new function of which the variable list is a combination of those of two functions
Function	copy() Makes a copy of a function
Errors	errors(Instances inst) Evaluates a function
int	insignificant(double sdy, Instances inst) Detects the most insignificant variable in the funcion
double	predict(Instance instance) Returns the predicted value of instance i by a function
Function	remove(int j) Removes a term from the function
java.lang.String	toString(Instances inst, int startPoint) Converts a function to a string

Methods inherited from class java.lang.Object

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

Constructor Detail

Function

public Function()

Constructs a function of constant value

Function

public Function(Instances inst)

Constucts a function with all attributes except the class in the inst

Parameters:

inst - instances

Function

public Function(int attr)

Constructs a function with one attribute

Parameters:

attr - an attribute

Method Detail

copy

public final Function copy()

Makes a copy of a function

Returns:

the copy of the function

toString

public final java.lang.String toString(Instances inst,
                                       int startPoint)
                                throws java.lang.Exception

Converts a function to a string

Parameters:

inst - instances

startPoint - the starting point on the screen; used to feed line before reaching beyond 80 characters

Returns:

the converted string

Throws:

java.lang.Exception - if something goes wrong

combine

public static final Function combine(Function f1,
                                     Function f2)

Constructs a new function of which the variable list is a combination of those of two functions

Parameters:

f1 - function 1

f2 - function 2

Returns:

the newly constructed function

errors

public final Errors errors(Instances inst)
                    throws java.lang.Exception

Evaluates a function

Parameters:

inst - instances

Returns:

the evaluation results

Throws:

java.lang.Exception - if something goes wrong

predict

public final double predict(Instance instance)

Returns the predicted value of instance i by a function

Parameters:

i - instance i

inst - instances

Returns:

the predicted value

insignificant

public final int insignificant(double sdy,
                               Instances inst)

Detects the most insignificant variable in the funcion

Parameters:

sdy - the standard deviation of the class variable

inst - instances

Returns:

the index of the most insignificant variable in the function

remove

public final Function remove(int j)

Removes a term from the function

Parameters:

j - the j-th index in the variable list in the function

Returns:

the new function with the term removed