Univariate statistical analysis of environmental (compositional) data:Problems and possibilities
Peter Filzmoser, Karel Hron, Clemens Reimann Received 8 May 2009 Received in revised form 24 July 2009 Accepted 5 August 200 abstract For almost 30 years it has been known that compositional (closed) data have special geometrical properties.In environmental sciences, where the concentration of chemical elements in different sample materials isinvestigated, almost all datasets are compositional. In general, compositional data are parts of a whole whichonly give relative information. Data that sum up to a constant, e.g. 100wt.%, 1,000,000 mg/kg are the bestknown example. It is widely neglected that the “closure” characteristic remains even if only one of all possible …