collaborators

6 papers

stat.ME2026

Informative Distance-Based Priors for Correlation Matrices Centred on a Target Reference

Anna Freni-Sterrantino, Janet van Niekerk, Elias Teixeira Krainski +3

Specifying a prior over the space of correlation matrices is a persistent challenge in Bayesian analysis. The space is a curved manifold whose dimension grows quadratically with th…

stat.ME2026

A flexible wrapped Lindley-type distribution for angular data modelling

Johan Ferreira, Delene van Wyk-de Ridder, Janet van Niekerk

Flexible distributions for modelling angular data have received considerable attention in recent years, with ongoing work extending existing circular models to provide greater flex…

stat.ME2026

A robust contaminated discrete Weibull regression model for outlier-prone count data

Divan A. Burger, Janet van Niekerk, Emmanuel Lesaffre

Count data often exhibit overdispersion driven by heavy tails or excess zeros, making standard models (e.g., Poisson, negative binomial) insufficient for handling outlying observat…

stat.ME2026

A Bayesian regression framework for circular models with INLA

Xiang Ye, Janet Van Niekerk, Haavard Rue

Regression models for circular variables are less developed, since the concept of building a linear predictor from linear combinations of covariates and various random effects, bre…

stat.ME2025

Outlier-robust copula regression for bivariate continuous proportions: an application to cushion plant vitality

Divan A. Burger, Janet van Niekerk, Peter C. le Roux +1

Continuous proportions measured on the same experimental unit often pose two challenges: interior outliers that inflate variance beyond the beta ceiling and residual dependence tha…

stat.CO2025

Leave-group-out cross-validation for latent Gaussian models

Zhedong Liu, Janet Van Niekerk, Haavard Rue

Evaluating the predictive performance of a statistical model is commonly done using cross-validation. Among the various methods, leave-one-out cross-validation (LOOCV) is frequentl…