Greenacre, MichaelUniversitat Pompeu Fabra. Departament d'Economia i Empresa2017-07-262017-07-262007-08-01Computational Statistics and Data Analysis, 2009, 53, pp. 3107-3116http://hdl.handle.net/10230/1151Power transformations of positive data tables, prior to applying the correspondence analysis algorithm, are shown to open up a family of methods with direct connections to the analysis of log-ratios. Two variations of this idea are illustrated. The first approach is simply to power the original data and perform a correspondence analysis this method is shown to converge to unweighted log-ratio analysis as the power parameter tends to zero. The second approach is to apply the power transformation to the contingency ratios, that is the values in the table relative to expected values based on the marginals this method converges to weighted log-ratio analysis, or the spectral map. Two applications are described: first, a matrix of population genetic data which is inherently two-dimensional, and second, a larger cross-tabulation with higher dimensionality, from a linguistic analysis of several books.application/pdfengL'accés als continguts d'aquest document queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commonsinfo:eu-repo/semantics/workingPaperbox-cox transformationchi-square distancecontingency ratiocorrespondence analysislog-ratio analysispower transformationratio datasingular value decompositionspectral mapStatistics, Econometrics and Quantitative Methodsinfo:eu-repo/semantics/openAccess