Compositional explanatory variables should not be directly used in a linear regression model because any inference statistic can become misleading. While various approaches for this problem were proposed, here an approach based on the isometric logratio (ilr) transformation is used. It turns out that the resulting model is easy to handle, and that parameter estimation can be done like in usual ...

Allometric regression (AR) has been widely used to model changes in the body composition of animals. However, predicted body component proportions based on AR equations do not necessarily sum to 1 and this discrepancy is confounded with treatment effects on components of the composition. Predicted component proportions are not bounded to lie between 0 and 1. An alternative method, compositional...

The main goal of this research work was to detect the different Cu mineralized zones in the Sungun porphyry deposit in NW Iran using the Spectrum-Volume (S-V) fractal modeling based on the sub-surface data for this deposit. This operation was carried out on an estimated Cu block model based on a Fast Fourier Transformation (FFT) using the C++ and MATLAB programing. The S-V log-log plot was gene...

This work relates native lactic acid bacteria (LAB) (Lactobacillus pentosus LPG1, L. Lp13, and Lactobacillus plantarum Lpl15) yeast (Wickerhamomyces anomalus Y12) starters to the volatile components (VOCs) produced in green Spanish-style table olives. For this aim, VOC profile was considered as compositional data (CoDa). The CoDa analysis generated new information on relationship among inocula ...

Although Aitchison’s [Aitchison, J., 1986. The Statistical Analysis of Compositional Data, Chapman and Hall, London] method of logratio transformation of compositional data is widely used in various domains, it is limited by the assumption of a strict non-negativity of the components and the requirement of special treatments in practice of the zero components. We propose a dimension-reduction a...

In this paper, we attempt to see further by relating theory with practice: First, review the principles on which three interrelated well developed methods for analysis and visualization of contingency tables compositional data are erected: Correspondence based Benzécri’s principle distributional equivalence, Goodman’s RC association model Yule’s scale invariance, Aitchison’s subcompositional co...

Data resulting from high-throughput biological experiments are frequently of relative nature. This implies that the most relevant information is on shape data distribution over features more than size measurements themselves. One well-established way to acknowledge this in statistical processing through logratio analysis. In current work, we introduce selective pivot coordinates as a new type o...