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stat.ME2026

Handling mild outliers and unobserved values in compositional datasets using finite mixtures of mean-parametrised Dirichlet models

Jason Pillay, Andriëtte Bekker, Cristina Tortora +1

Heterogeneous compositional data may be simultaneously affected by missing values and atypical points, posing challenges for both clustering and outlier detection. We develop a mix…

stat.ME2026

Handling Missingness and Censoring in Dirichlet Mixture Models

Jason Pillay, Andriette Bekker, Cristina Tortora +1

The paper introduces a likelihood‑based EM algorithm for fitting finite mixtures of Dirichlet distributions to compositional data that contain missing or left‑censored components,…

stat.ME2026

Handling Missingness and Censoring in Dirichlet Models

J. Pillay, A. Bekker, C. Tortora +1

Likelihood-based inference for compositional data generally requires fully observed compositions, hindering the direct treatment of missing or censored components on the simplex. I…

stat.ME2025

Sleep pattern profiling using a finite mixture of contaminated multivariate skew-normal distributions on incomplete data

Jason Pillay, Cristina Tortora, Antonio Punzo +1

Medical data often exhibit characteristics that make cluster analysis particularly challenging, such as missing values, outliers, and cluster features like skewness. Typically, suc…

stat.ME2025

Clustering data with values missing at random using scale mixtures of multivariate skew-normal distributions

Jason Pillay, Cristina Tortora, Antonio Punzo +1

Handling missing data is a major challenge in model-based clustering, especially when the data exhibit skewness and heavy tails. We address this by extending the finite mixture of…