Recent advances in directional statistics

A Pewsey, E García-Portugués - Test, 2021 - Springer
Mainstream statistical methodology is generally applicable to data observed in Euclidean
space. There are, however, numerous contexts of considerable scientific interest in which …

Initialization of hidden Markov and semi‐Markov models: A critical evaluation of several strategies

A Maruotti, A Punzo - International Statistical Review, 2021 - Wiley Online Library
The expectation–maximization (EM) algorithm is a familiar tool for computing the maximum
likelihood estimate of the parameters in hidden Markov and semi‐Markov models. This …

Model-based time-varying clustering of multivariate longitudinal data with covariates and outliers

A Maruotti, A Punzo - Computational Statistics & Data Analysis, 2017 - Elsevier
A class of multivariate linear models under the longitudinal setting, in which unobserved
heterogeneity may evolve over time, is introduced. A latent structure is considered to model …

Dynamic mixtures of factor analyzers to characterize multivariate air pollutant exposures

A Maruotti, J Bulla, F Lagona, M Picone, F Martella - 2017 - projecteuclid.org
The assessment of pollution exposure is based on the analysis of a multivariate time series
that include the concentrations of several pollutants as well as the measurements of multiple …

[HTML][HTML] The joint projected normal and skew-normal: A distribution for poly-cylindrical data

G Mastrantonio - Journal of Multivariate Analysis, 2018 - Elsevier
This paper introduces a multivariate circular–linear (or poly-cylindrical) distribution obtained
by combining the projected and the skew-normal. We show the flexibility of our proposal, its …

CircSpaceTime: an R package for spatial and spatio-temporal modelling of circular data

G Jona Lasinio, M Santoro… - Journal of Statistical …, 2020 - Taylor & Francis
CircSpaceTime is the only R package, currently available, that implements Bayesian models
for spatial and spatio-temporal interpolation of circular data. Such data are often found in …

A circular nonhomogeneous hidden Markov field for the spatial segmentation of wildfire occurrences

J Ameijeiras‐Alonso, F Lagona, M Ranalli… - …, 2019 - Wiley Online Library
Motivated by studies of wildfire seasonality, we propose a nonhomogeneous hidden Markov
random field to model the spatial distribution of georeferenced fire occurrences during the …

Model‐based clustering for noisy longitudinal circular data, with application to animal movement

M Ranalli, A Maruotti - Environmetrics, 2020 - Wiley Online Library
In this work, we introduce a model for circular data analysis to robustly estimate parameters,
under a longitudinal clustering setting. A hidden Markov model for longitudinal circular data …

Invariance properties and statistical inference for circular data

G Mastrantonio, GJ Lasinio, A Maruotti, G Calise - Statistica Sinica, 2019 - JSTOR
Statistical inference on the circle may strongly depend on the chosen reference system.
Here, we introduce necessary and sufficient conditions to avoid inferential problems and …

A random‐effects model for clustered circular data

LP Rivest, S Kato - Canadian Journal of Statistics, 2019 - Wiley Online Library
This article considers a circular regression model for clustered data, where both the cluster
effects and the regression errors have von Mises distributions. It involves β, a vector of …