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Departament d'Enginyeria Informàtica i Matemàtiques
Universitat Rovira i Virgili

MultiDendrograms

A hierarchical clustering tool

Index

Description

MultiDendrograms is a simple yet powerful program to make the Hierarchical Clustering of real data, distributed under an Open Source license. Starting from a distances (or weights) matrix, MultiDendrograms calculates its dendrogram using the most common Agglomerative Hierarchical Clustering algorithms, allows the tuning of many of the graphical representation parameters, and the results may be easily exported to file. A summary of characteristics:

MultiDendrograms implements the variable-group algorithms in [1] to solve the non-uniqueness problem found in the standard pair-group algorithms and implementations. This problem arises when two or more minimum distances between different clusters are equal during the amalgamation process. The standard approach consists in choosing a pair, breaking the ties between distances, and proceeds in the same way until the final hierarchical classification is obtained. However, different clusterings are possible depending on the criterion used to break the ties (usually a pair is just chosen at random!), and the user is unaware of this problem.

The variable-group algorithms group more than two clusters at the same time when ties occur, given rise to a graphical representation called multidendrogram. Their main properties are:

Comparison with other applications

How do other applications deal with ties?

How do I know if there are ties in my data?

Reference

[1] Solving Non-uniqueness in Agglomerative Hierarchical Clustering Using Multidendrograms
Alberto Fernández and Sergio Gómez
Journal of Classification 25 (2008) 43-65.
(pdf) (doi) (Springer)

Download

Please cite [1] if you use MultiDendrograms in your publications.

Installation

No installation needed, just unzip multidendrograms-xxx.zip and run multidendrograms.bat (Windows), multidendrograms.sh (Linux) or multidendrograms.jar (all OS). Java version 6 (also known as Java 1.6) or higher is required.

Gallery

MultiDendrograms image 1      MultiDendrograms image 2

MultiDendrograms image 3      MultiDendrograms image 4

History

MultiDendrograms 3.2:

MultiDendrograms 3.1:

MultiDendrograms 3.0:

MultiDendrograms 2.1:

MultiDendrograms 2.0:

MultiDendrograms 1.0: