Report on Optimal Substructure Techniques for Stellar, Gas and Combined
  Samples
  This document aims at reviewing the different types of clustering algorithms
and substructures detection techniques in order to study the spatial and
kinematic clustering of stars and detect the gas components in molecular
clouds. It is the deliverable: Report on Optimal Substructure Techniques for
Stellar, Gas and Combined Samples, for the EU H2020 (COMPET-5-2015 - Space)
project (A Gaia and Herschel Study of the Density Distribution and Evolution of
Young Massive Star Clusters), Grant Agreement Number: 687528, with abbreviated
code name StarFormMapper (SFM) project. The document is organized in the
following sections: 1. General Introduction 2. Clustering of Discrete
Distributions 3. Clustering of Continuous Distributions 4. Clustering in
Astrophysics 5. StarFormMapper 6. Summary and Conclusions
