All Packages  Class Hierarchy  This Package  Previous  Next  Index  WEKA's home

Class weka.core.DistanceFunction

java.lang.Object
    |
    +----weka.core.DistanceFunction

public abstract class DistanceFunction

extends java.lang.Object

implements java.io.Serializable

Version:

$Revision: 1.2 $

Author:

Gabi Schmidberger (gabi@cs.waikato.ac.nz)

m_Ranges

the range of the attributes

DistanceFunction()

Constructs a distance function object.

DistanceFunction(Instances)

Constructs a distance function object.

DistanceFunction(Instances, double[][])

Constructs a distance function object.

checkInstances()

Checks the instances if compatibel with the distance function.

closestPoint(Instance, Instances, int[])

Returns the index of the closest point to the current instance.

distance(Instance, Instance)

Calculates the distance (or similarity) between two instances.

getMiddle(double[])

Returns value in the middle of the two parameter values.

toString()

Converts a DistanceFunction object to a string

updateRanges(Instance)

Update the ranges if a new instance comes.

valueIsSmallerEqual(Instance, int, double)

Returns true if the value of the given dimension is smaller or equal the value to be compared with.

public double[][] m_Ranges

          the range of the attributes

public DistanceFunction()

          Constructs a distance function object.

public DistanceFunction(Instances data)

          Constructs a distance function object.

Parameters:

data - the instances the distance function should work on.

public DistanceFunction(Instances data,
                        double ranges[][])

          Constructs a distance function object. Ranges are already given

Parameters:

data - the instances the distance function should work on.

ranges - the min and max values of the attribute values

public abstract double distance(Instance first,
                                Instance second) throws java.lang.Exception

          Calculates the distance (or similarity) between two instances.

Parameters:

first - the first instance

second - the second instance

Returns:

the distance between the two given instances,

public abstract double getMiddle(double ranges[])

          Returns value in the middle of the two parameter values.

Parameters:

range - the ranges to this dimension

Returns:

the middle value

public abstract void checkInstances() throws java.lang.Exception

          Checks the instances if compatibel with the distance function.

Parameters:

range - the ranges to this dimension

Returns:

the middle value

public abstract boolean valueIsSmallerEqual(Instance instance,
                                            int dim,
                                            double value)

          Returns true if the value of the given dimension is smaller or equal the value to be compared with.

Parameters:

instance - the instance where the value should be taken of

dim - the dimension of the value

the - value to compare with

Returns:

true is value of instance is smaller or equal value

public int closestPoint(Instance instance,
                        Instances allPoints,
                        int pointList[]) throws java.lang.Exception

          Returns the index of the closest point to the current instance. Index is index in Instances object that is the second parameter.

Parameters:

instance - the instance to assign a cluster to

centers - all centers

centList - the centers to cluster the instance to

Returns:

a cluster index

public void updateRanges(Instance instance)

          Update the ranges if a new instance comes.

Parameters:

instance - the new instance

public java.lang.String toString()

          Converts a DistanceFunction object to a string

Returns:

a string describing a distance function

Overrides:

toString in class java.lang.Object

All Packages  Class Hierarchy  This Package  Previous  Next  Index  WEKA's home