6 papers
Non--negative matrix factorization using the \textit{R} package \textsf{nnmf}
Volkan Sevinç, Nikolas Kontemeniotis, Theodoros Perdikis +1
Non--negative matrix factorization (NMF) has become an established dimensionality reduction technique for extracting latent structures from non--negative data and has found widespr…
Model--based clustering for spherical and hyper--spherical data using elliptically symmetric distributions
Theodoros Perdikis, Nader Alharbi, Michail Tsagris
Model--based clustering for directional data data has attracted a lot of interest, but most methods utilize rotationally symmetric distributions. This paper suggests the use of ell…
Scalable approximation of the transformation-free linear simplicial-simplicial regression via constrained iterative reweighted least squares
Michail Tsagris, Omar Alzeley
Simplicia-simplicial regression concerns statistical modeling scenarios in which both the predictors and the responses are vectors constrained to lie on the simplex. \cite{fiksel20…
Simplicial clustering using the --transformation
Michail Tsagris, Nikolaos Kontemeniotis
We introduce two simplicial clustering approaches for compositional data, that are adaptations of the --means and of the Gaussian mixture models algorithms, by employing the $α…
Constrained least squares simplicial-simplicial regression
Michail Tsagris
Simplicial-simplicial regression refers to the regression setting where both the responses and predictor variables lie within the simplex space, i.e. they are compositional. For th…
Directional data analysis using the spherical Cauchy and the Poisson kernel-based distribution
Michail Tsagris, Panagiotis Papastamoulis, Shogo Kato
In 2020, two novel distributions for the analysis of directional data were introduced: the spherical Cauchy distribution and the Poisson kernel-based distribution. This paper provi…