keel.Algorithms.Preprocess.Missing_Values.fkmeans

Class fuzzygCenter

java.lang.Object

keel.Algorithms.Preprocess.Missing_Values.fkmeans.fuzzygCenter

public class fuzzygCenter
extends java.lang.Object

This class represents a group of centers (centroids) of a set of fuzzy clusters

Since:

JDK 1.5

Version:

0.1

Author:

Written by Julián Luengo Martín 03/12/2006

Constructor Summary

Constructors

Constructor and Description
fuzzygCenter() Creates a new instance of gCenter
fuzzygCenter(int k, int ndatos, int nvariables, double fuzzifier) Creates a new instance of gCenter with provided number of centers, number of instances of the data set and number of attributes

Method Summary

Modifier and Type	Method and Description
void	copyCenter(Instance i, int c) this function initializes a center with the values of a given instance.
double	distance(Instance i, int k) Computes the distance between a instances (without previous normalization) and one clusters (i.e. its centroid).
int	getClusterOf(Instance i) Returns the cluster to which the given instance belongs to
double	getMembershipOf(int orderOf_i, int k) Returns the membership degree of the instance for a given cluster
int	nearestCenter(Instance inst) Computes the nearest cluster to the given instance (for nominal values only)
void	recalculateCenters(InstanceSet IS) Recalculates all the centroids using a given InstanceSet, to reduce the sum of the distances for each object from the centroid of the cluster to which the object belongs
void	setMembershipOf(Instance i, int orderOf_i) Computes the memebership degree of a given instance to all the clusters
java.lang.String	valueAt(int cluster, int position) Get the value of an attribute of the indicated centroid

Methods inherited from class java.lang.Object

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

Constructor Detail

fuzzygCenter

public fuzzygCenter()

Creates a new instance of gCenter

fuzzygCenter

public fuzzygCenter(int k,
                    int ndatos,
                    int nvariables,
                    double fuzzifier)

Creates a new instance of gCenter with provided number of centers, number of instances of the data set and number of attributes

Parameters:

k - Fixed number of centroids

ndatos - number of instances in the data set related to this object

nvariables - number of attributes

fuzzifier - The parameter m (> 1) used to fuzzify the clusters

Method Detail

distance

public double distance(Instance i,
                       int k)

Computes the distance between a instances (without previous normalization) and one clusters (i.e. its centroid).

Parameters:

i - The reference instance

k - The cluster number

Returns:

The Euclidean distance between i and k

copyCenter

public void copyCenter(Instance i,
                       int c)

this function initializes a center with the values of a given instance.

Parameters:

i - the initialization instance

c - the index of the cluster to be initialized

recalculateCenters

public void recalculateCenters(InstanceSet IS)

Recalculates all the centroids using a given InstanceSet, to reduce the sum of the distances for each object from the centroid of the cluster to which the object belongs

Parameters:

IS - The reference InstanceSet

setMembershipOf

public void setMembershipOf(Instance i,
                            int orderOf_i)

Computes the memebership degree of a given instance to all the clusters

Parameters:

i - The instance to update the memberships

orderOf_i - The index of the instance

getMembershipOf

public double getMembershipOf(int orderOf_i,
                              int k)

Returns the membership degree of the instance for a given cluster

Parameters:

orderOf_i - the index of the instance

k - the index of the considered cluster

Returns:

the membership degree of instance i to cluster k

nearestCenter

public int nearestCenter(Instance inst)

Computes the nearest cluster to the given instance (for nominal values only)

Parameters:

inst - The instance we are interested to compare

Returns:

The index of the nearest cluster

getClusterOf

public int getClusterOf(Instance i)

Returns the cluster to which the given instance belongs to

Parameters:

i - given instance

Returns:

The index of the cluster to this isntance belongs to.

valueAt

public java.lang.String valueAt(int cluster,
                                int position)

Get the value of an attribute of the indicated centroid

Parameters:

cluster - The index of the cluster (centroid)

position - The attribute (dimension) to be obtained

Returns:

the current value of the dimension of the given cluster