Outlier detection is an important task for the statistical analysis of multivariate data, because often the outliers contain important information about the data structure. In compositional data, represented usually as proportions subject to a unit sum constraint, the ratios between the parts (variables) contain the essential information. This inherent property is, however, incompatible with th...

In the life sciences, many measurement methods yield only the relative abundances of different components in a sample. With such relative-or compositional-data, differential expression needs careful interpretation, and correlation-a statistical workhorse for analyzing pairwise relationships-is an inappropriate measure of association. Using yeast gene expression data we show how correlation can ...

eteorites yield a wealth of information concerning Solar System origin, geochemical evolution of primitive parent objects, and irradiation histories of material in space. Since the numerous (approximately 16,000) antarctic meteorites include many of rare or unique types, current extraterrestrial materials research attention focuses on this population. Antarctic meteorites also have the potentia...

In this paper, we construct two classes of permutation polynomials over Fq2 with odd characteristic from rational Rédei functions. A complete characterization of their compositional inverses is also given. These permutation polynomials can be generated recursively. As a consequence, we can generate recursively permutation polynomials with arbitrary number of terms. More importantly, the conditi...

Watershed segmentation of spectral images is typically achieved by first transforming the high-dimensional input data into a scalar boundary indicator map which is used to derive the watersheds. We propose to combine a Random Forest classifier with the watershed transform and introduce three novel methods to obtain scalar boundary indicator maps from class probability maps. We further introduce...

A Microsoft Excel spreadsheet has been programmed to assist with classification of chemical analyses of orthorhombic and monoclinic amphiboles following the 2012 nomenclature recommended by the International Mineralogical Association. The spreadsheet is intended for use only with compositional data (wt% oxides and halogens, rather than atomic proportions) and provides options for the estimation...

We present a unified approach to describing and linking several methods for representing categorical data in a contingency table. These methods include: correspondence analysis, Hellinger distance analysis, the log-ratio alternative, which is appropriate for compositional data, and the non-symmetrical correspondence analysis. We also present two solutions working with cummulative frequencies.

A compositional parallel program is a program constructed by composing component programs in parallel where the composed pro gram inherits properties of its components In this paper we describe a small extension of C called Compositional C or CC which is an object oriented notation that supports compositional parallel programming CC integrates di erent paradigms of parallel pro gramming data pa...