org.apache.commons.math3.ml.clustering.evaluation

Class SumOfClusterVariances<T extends Clusterable>

java.lang.Object

org.apache.commons.math3.ml.clustering.evaluation.ClusterEvaluator<T>

org.apache.commons.math3.ml.clustering.evaluation.SumOfClusterVariances<T>

Type Parameters:

T - the type of the clustered points

public class SumOfClusterVariances<T extends Clusterable>
extends ClusterEvaluator<T>

Computes the sum of intra-cluster distance variances according to the formula:

 \( score = \sum\limits_{i=1}^n \sigma_i^2 \)
 

where n is the number of clusters and \( \sigma_i^2 \) is the variance of intra-cluster distances of cluster \( c_i \).

Since:

3.3

Constructor Summary

Constructors

Constructor and Description
SumOfClusterVariances(DistanceMeasure measure)

Method Summary

Modifier and Type	Method and Description
double	score(java.util.List<? extends Cluster<T>> clusters) Computes the evaluation score for the given list of clusters.

Methods inherited from class org.apache.commons.math3.ml.clustering.evaluation.ClusterEvaluator

isBetterScore

Methods inherited from class java.lang.Object

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

Constructor Detail

SumOfClusterVariances

public SumOfClusterVariances(DistanceMeasure measure)

Parameters:

measure - the distance measure to use

Method Detail

score

public double score(java.util.List<? extends Cluster<T>> clusters)

Computes the evaluation score for the given list of clusters.

Specified by:

score in class ClusterEvaluator<T extends Clusterable>

Parameters:

clusters - the clusters to evaluate

Returns:

the computed score