at.tuwien.ifs.somtoolbox.visualization.clustering
Class AbstractWardsLinkageTreeBuilder

java.lang.Object
  extended by at.tuwien.ifs.somtoolbox.visualization.clustering.TreeBuilder
      extended by at.tuwien.ifs.somtoolbox.visualization.clustering.AbstractWardsLinkageTreeBuilder
Direct Known Subclasses:
WardsLinkageTreeBuilder, WardsLinkageTreeBuilderAll

public abstract class AbstractWardsLinkageTreeBuilder
extends TreeBuilder

Version:
$Id: AbstractWardsLinkageTreeBuilder.java 3583 2010-05-21 10:07:41Z mayer $
Author:
Rudolf Mayer

Field Summary
 
Fields inherited from class at.tuwien.ifs.somtoolbox.visualization.clustering.TreeBuilder
level, monitor, progress, progressWriter
 
Constructor Summary
AbstractWardsLinkageTreeBuilder()
           
 
Method Summary
protected  double calcESSincrease(ClusterNode n1, ClusterNode n2)
          Calculates the increase of the Error Sum of Squares if the two Clusters are united.
 
Methods inherited from class at.tuwien.ifs.somtoolbox.visualization.clustering.TreeBuilder
allowAborting, createTree, finishMonitor, getClusteringAlgName, incrementMonitor, resetMonitor, setMonitor
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

AbstractWardsLinkageTreeBuilder

public AbstractWardsLinkageTreeBuilder()
Method Detail

calcESSincrease

protected double calcESSincrease(ClusterNode n1,
                                 ClusterNode n2)
Calculates the increase of the Error Sum of Squares if the two Clusters are united. To get the "real" Error Sum of Squares increase one must take the square root of the returned value. This step is left out of here to save computation time, as it changes nothing in the order of the distances if this calculation is left out for all distances.

Returns:
the 'distance' value