Browsing by Author "Pawlowsky Glahn, Vera"
Now showing items 116 of 16

Balances: a new perspective for microbiome analysis
Rivera Pinto, J.; Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera; Paredes, Raul; Noguera Julian, Marc; Calle, M. L. (201807)
Article
Open AccessHighthroughput sequencing technologies have revolutionized microbiome research by allowing the relative quantification of microbiome composition and function in different environments. In this work we focus on the ... 
Bayes linear spaces
van den Boogaart, Karl Gerald; Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera (201012)
Article
Open AccessLinear spaces consisting of $\sigma$finite probability measures and infinite measures (improper priors and likelihood functions) are defined. The commutative group operation, called perturbation, is the updating given by ... 
Bayes linear spaces
van den Boogaart, Karl Gerald; Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera (Institut d'Estadística de Catalunya, 2010)
Article
Open AccessLinear spaces consisting of finite probability measures and infinite measures (improper priors and likelihood functions) are defined. The commutative group operation, called perturbation, is the updating given by Bayes ... 
Chronic kidney disease of unknown origin is associated with environmental urbanisation in Belfast, UK
McKinley, Jennifer M.; Mueller, Ute; Atkinson, Peter M.; Ofterdinger, Ulrich; Cox, Siobhan F.; Doherty, Rory; Fogarty, Damian; Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera (202107)
Article
Open AccessChronic kidney disease (CKD), a collective term for many causes of progressive renal failure, is increasing worldwide due to ageing, obesity and diabetes. However, these factors cannot explain the many environmental clusters ... 
Evidence functions: a compositional approach to information
Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera (Institut d'Estadística de Catalunya, 20180701)
Article
Open AccessThe discrete case of Bayes’ formula is considered the paradigm of information acquisition. Prior and posterior probability functions, as well as likelihood functions, called evidence functions, are compositions following ... 
Evidence information in Bayesian updating
Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera (CIMNE, 201106)
Other
Open AccessBayes theorem (discrete case) is taken as a paradigm of information acquisition. As mentioned by Aitchison, Bayes formula can be identiﬁed with perturbation of a prior probability vector and a discrete likelihood function, ... 
Exploration of geochemical data with compositional canonical biplots
Graffelman, Jan; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José; Buccianti, A. (20180725)
Article
Open AccessThe study of the relationships between two compositions is of paramount importance in geochemical data analysis. This paper develops a compositional version of canonical correlation analysis, called CoDACCO, for this ... 
Microbiome datasets are compositional: and this is not optional
Gloor, Gregory B.; Macklaim, Jean M.; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José (201711)
Article
Open AccessDatasets collected by highthroughput sequencing (HTS) of 16S rRNA gene amplimers, metagenomes or metatranscriptomes are commonplace and being used to study human disease states, ecological differences between sites, and ... 
Modified KolmogorovSmirnov test of goodness of fit
Monti, Gianna S.; Mateu Figueras, Gloria; Ortego Martínez, María Isabel; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José (2017)
Conference report
Open AccessA modified version of the KolmogorovSmirnov (KS) test is presented as a tool to assess whether a specified, although arbitrary, probability model is unsuitable to describe the underlying distribution of a set of observations. ... 
Principal balances
Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José; Tolosana Delgado, Raimon (International Centre for Numerical Methods in Engineering (CIMNE), 2011)
Conference report
Open AccessPrincipal balances are defined as a sequence of orthonormal balances which maximize successively the explained variance in a data set. Apparently, computing principal balances requires an exhaustive search along all possible ... 
Principal balances
Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José; Tolosana Delgado, Raimon (CIMNE, 2011)
Conference report
Open AccessPrincipal balances are de ned as a sequence of orthonormal balances which maximize successively the explained variance in a data set. Apparently, computing principal balances requires an exhaustive search along all ... 
Rethinking the KolmogorovSmirnov test of Goodness of fit in a compositional way
Monti, Gianna S.; Mateu Figueras, Gloria; Ortego Martínez, María Isabel; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José (Pearson, 2018)
Conference report
Open AccessThe Kolmogorov Smirnov test (KS) is a well known test used to asses how a set of observations is significantly different from the probability model specified under the null hypothesis. The KS test statistic quantifies the ... 
Some thoughts on counts in sequencing studies
Egozcue Rubí, Juan José; Graffelman, Jan; Ortego Martínez, María Isabel; Pawlowsky Glahn, Vera (20201201)
Article
Open AccessMeasurements in sequencing studies are mostly based on counts. There is a lack of theoretical developments for the analysis and modelling of this type of data. Some thoughts in this direction are presented, which might ... 
Survey data on perceptions of contraceptive methods as compositional tables
Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José; Planes Pedra, Montserrat (201807)
Article
Open AccessThis paper studies the relative evaluation of young people and the possible benefits associated with three methods of avoiding sexually transmitted infections/AIDS and/or unwanted pregnancies (condoms, contraceptive pills, ... 
The normal distribution in some constrained sample spaces
Mateu Figueras, Gloria; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José (20130101)
Article
Open AccessPhenomena with a constrained sample space appear frequently in practice. This is the case, for example, with strictly positive data, or with compositional data, such as percentages or proportions. If the natural measure ... 
The shiftedscaled Dirichlet distribution in the simplex
Monti, G.S.; Mateu Figueras, G.; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José (CIMNE, 2011)
Conference report
Open AccessPerturbation and powering are two operations in the simplex that define a vectorspace structure. Perturbation and powering in the simplex play the same role as the sum and product by scalars in real space. A standard ...