coreComponents
Class EuclideanDistanceMetric

java.lang.Object
  |
  +--coreComponents.DistanceMetric
        |
        +--coreComponents.EuclideanDistanceMetric

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

public class EuclideanDistanceMetric

extends DistanceMetric

implements java.lang.Cloneable, java.io.Serializable

Implementing Euclidean distance (or similarity) function. One object defines not one distance but the data model in which the distances between objects of that data model can be computed. Attention: For efficiency reasons the use of consistency checks (like are the data models of the two instances exactly the same), is low. This has been updated for my own personal (davidl) needs!

Version:

$Revision: 1.3 $

Author:

Gabi Schmidberger (gabi@cs.waikato.ac.nz), David Lindsay (davidl@cs.rhul.ac.uk)

See Also:

Serialized Form

Field Summary

Instances

m_Model

Constructor Summary

EuclideanDistanceMetric()
Constructs an Euclidean Distance object.

EuclideanDistanceMetric(Instances data)
Constructs an Euclidean Distance object.

Method Summary

void	checkInstances() Checks the instances.
boolean	checkInstances(Instances instances) Check if the instances are valid for the distance metric.
double	distance(Instance first, Instance second) Calculates the distance (or similarity) between two instances.
static void	main(java.lang.String[] args) Main method for testing this class.
void	reset(Instances instances) This function is useful if we need to reinitialise the distance metric without using the constructor
java.lang.String	toString() Documents the content of an EuclideanDistance object in a string.
void	updateRanges(Instance inst1) Update the ranges of the distance metric with a new training instance.

Methods inherited from class coreComponents.DistanceMetric

forName

Methods inherited from class java.lang.Object

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

Field Detail

m_Model

public Instances m_Model

Constructor Detail

EuclideanDistanceMetric

public EuclideanDistanceMetric()

Constructs an Euclidean Distance object.

EuclideanDistanceMetric

public EuclideanDistanceMetric(Instances data)

Constructs an Euclidean Distance object.

Parameters:

data - the instances the distance function should work on

Method Detail

checkInstances

public boolean checkInstances(Instances instances)

Check if the instances are valid for the distance metric.

Specified by:

checkInstances in class DistanceMetric

Parameters:

instances - the training instances to be checked

Returns:

true if the instances are valid, false otherwise

reset

public void reset(Instances instances)

This function is useful if we need to reinitialise the distance metric without using the constructor

Specified by:

reset in class DistanceMetric

updateRanges

public void updateRanges(Instance inst1)

Update the ranges of the distance metric with a new training instance.

Specified by:

updateRanges in class DistanceMetric

Parameters:

inst1 - the instance to update with

Returns:

nothing

distance

public double distance(Instance first,
                       Instance second)

Calculates the distance (or similarity) between two instances.

Specified by:

distance in class DistanceMetric

Parameters:

first - the first instance

second - the second instance

Returns:

the distance between the two given instances,

checkInstances

public void checkInstances()
                    throws java.lang.Exception

Checks the instances. Dataset should only contain nominal or stringumeric attributes.

java.lang.Exception

toString

public java.lang.String toString()

Documents the content of an EuclideanDistance object in a string.

Specified by:

toString in class DistanceMetric

Returns:

the converted string

main

public static void main(java.lang.String[] args)

Main method for testing this class.