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In this paper, we distinguish between two kinds of compositional data sets: elementary and aggregate. This fact will help us to decide the choice of the weights to use in log interaction analysis of aggregate compositional vectors. We show that in the aggregate case, the underlying given data form a paired data sets composed of responses and qualitative covariates; this fact helps us to propose two approaches for analysis-visualization of data named log interaction of aggregates and aggregate of log interactions. Furthermore, we also show the first-order approximation of log interaction of a cell for different choices of the row and column weights., Comment: 3 figures, 1 table, 17 pages

We prospect for a clear simple picture on CA of power transformed or the Box-Cox transformed data initiated since 2009 by Grenacre. We distinguish two types of data sets : strictly positive and with zeros; we concentrate on the latter., Comment: The R code is included. arXiv admin note: text overlap with arXiv:2202.01620

In his seminal paper Goodman (1996) introduced marginal-free correspondence analysis; where his principal aim was to reconcile Pearson correlation measure with Yule's association measure in the analysis of contingency tables. We show that marginal-free correspondence analysis is a particular case of correspondence analysis with prespecified weights studied in the beginning of the 1980s by Benz\'ecri and his students. Furthermore, we show that it is also a particular first-order approximation of logratio analysis with uniform weights. Key words: Marginal-free correspondence analysis; logratio analysis; interactions; scale invariance; taxicab singular value decomposition., Comment: 16 pages

Collins(2002, 2011) raised a number of issues with regards to correspondence analysis (CA), such as: qualitative information in a CA map versus quantitative information in the relevant contingency table; the interpretation of a CA map is difficult and its relation with the \% of inertia (variance) explained. We tackle these issues by considering CA and taxicab CA (TCA) as a stepwise Hotelling/Tucker decomposition of the cross-covariance matrix of the row and column categories into four quadrants. The contents of this essay are: First, we review the notion of quality/quantity in multidimensional data analysis as discussed by Benz\'{e}cri, who based his reflections on Aristotle. Second, we show the importance of unravelling the interrelated concepts of dependence/heterogeneity structure in a contingency table; and to picture them two maps are needed. Third, we distinguish between intrinsic and extrinsic quality of a principal dimension; the intrinsic quality is based on the signs of the residuals in the four quadrants, hence to the interpretability. Furthermore, we provide quantifications of the intrinsic quality and use them to uncover structure in particular in sparse contingency tables. Finally, we emphasize the importance of looking at the residual cross-covariance values at each iteration., Comment: 34 pages, 4 figures, 10 tables. arXiv admin note: substantial text overlap with arXiv:2011.00544

Collins' (2002) statement "correspondence analysis makes you blind" followed after his seriation like description of a brand attribute count data set analyzed by Whitlark and Smith (2001), who applied correspondence analysis. In this essay we comment on Collins' statement within taxicab correspondence analysis framework by simultaneously decomposing the covariance matrix and its associated density matrix, thus interpreting two interrelated maps for contingency tables : TCov map and TCA map., Change of the title, and doubly extended version is posted on the arXiv as arXiv:2108.10685

This paper compares the method of Correspondence Analysis (CA) for finding patterns in archaeological sites by artifacts abundance data, with a robust variant, named Taxicab Correspondence Analysis (TCA). We show that this comparison is useful, especially for sparse tables with outliers. We identify three kinds of outliers. Three well-known datasets are reanalyzed.

Visualization and interpretation of contingency tables by correspondence analysis (CA), as developed by Benzecri, has a rich structure based on Euclidean geometry. However, it is a well established fact that, often CA is very sensitive to sparse contingency tables, where we caracterize sparsity as the existence of relatively high-valued counts, rare observations discussed by Rao (1995), and zero-block structure emphasized by Novak and Bar-Hen (2005) and Greenacre (2013). In this paper, we aim to emphasize the important roles played by L1 and L2 geometries. This will be done by comparing the maps obtained by CA with the maps obtained by taxicab correspondence analysis (TCA), where TCA is a robust L1 variant of correspondence analysis. If the projections of view of both maps are quite different, we refer to this phenomenon as parallax. In astronomy, parallax means the apparent change in the position of an object as seen from two different points. In our case the two different points correspond to the two different geometries, Euclidean and Taxicab. The existence of a parallax highlights the important, but hidden, role of the underlying geometry in the interpretation of the maps obtained in multivariate data analysis. We emphasize the following fact: Only by comparing CA and TCA graphical displays, we are able to reveal the phenomenon of parallax. Examples are provided., Comment: 23 pages, 4 figures

The aim of this paper is the introduction of a new method for the numerical computation of the rank of a three-way array. We show that the rank of a three-way array over R is intimately related to the real solution set of a system of polynomial equations. Using this, we present some numerical results based on the computation of Grobner bases. Key words: Tensors; three-way arrays; Candecomp/Parafac; Indscal; generic rank; typical rank; Veronese variety; Segre variety; Grobner bases. AMS classification: Primary 15A69; Secondary 15A72, 15A18., Comment: 21 pages