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Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada  
Tolosana Delgado, Raimon  
2011 May 11  
A general problem in compositional data analysis is the unmixing of a composition into a series of pure endmembers. In its most complex version, one does neither know the composition of these endmembers, nor their relative contribution to each observed composition. The problem is particularly cumbersome if the number of endmembers is larger than the number of observed components. This contribution proposes a possible solution of this underdetermined problem. The proposed method starts assuming that the endmember composition is known. Then, a geometric characterization of the problem allows to find the set of possible endmember proportions compatible with the observed composition. Within this set any solution may be valid, but some are more likely than other. To use this idea and choose the “most likely” solution in each case, the problem can be tackled with Bayesian MarkovChain MonteCarlo techniques. Finally, once we are familiar with MCMC, it is quite straightforward to allow the endmember compositions to randomly vary, and use the same MCMC to estimate the endmember composition most compatible with the studied data  
application/pdf  
http://hdl.handle.net/10256/13604  
eng  
Universitat de Girona. Departament d’Informàtica i Matemàtica Aplicada  
CoDaWork 2011. The 4th International Workshop on Compositional Data Analysis  
Tots els drets reservats  
Anàlisi multivariable  Congressos
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Unmixing Compositional data with Bayesian Techniques  
info:eurepo/semantics/conferenceObject  
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