Matthias Templ

Zurich University of Applied Sciences, Institute of Data Analysis and Process Design Winterthur


Compositional data analysis with an application to our favourite drinks

​Compositional data are nowadays widely accepted as multivariate observations carrying relative information. Compositional data follow the principle of scale invariance, typically being represented in proportions, percentages. In other words, for compositional data the relevant information is contained in the (log-)ratios between the components (parts). Compositional data are present in almost any field of research. Examples for compositional data in Official Statistics are, for example, expenditures, tax or wage components or percentages and ratios reported in various tables.

A short introduction to compositional data analysis will be given. Through data from our favourite drinks, the seminar talk will then show the usefulness of the representation of data in isometric coordinates and the analysis of these coordinates instead of analysing the raw data on the simplex. As a side note of the talk, we want to answer such important questions of life: how should we store beer or is the quality of beer depends on its age only? Should you drink blended coffee or is Scottish Whisky really different to Irish or American Whiskey?