Discriminant analysis for a folded Watson distribution

• Type: Article in International Scientific Journal
• Date: 2025

Authors

Adelaide Figueiredo (Author) FEP; Fernanda Figueiredo (Author) FEP

Journal

Title: Journal of Applied Statistics

Pages: 1-19

ISSN: 0266-4763

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-019-K0H

DOI: 10.1080/02664763.2025.2522769

Abstract (EN): When directional data fall in the positive orthant of the unit hypersphere, a folded directional distribution is preferred over a simple directional distribution for modeling the data. Since directional data, especially axial data, can be modeled using a Watson distribution, this paper considers a folded Watson distribution for such cases. We first address the parameter estimation of this distribution using maximum likelihood, which requires a numerical algorithm to solve the likelihood equations. We use the Expectation-Maximization (EM) algorithm to obtain these estimates and to analyze the properties of the concentration estimator through simulation. Next, we propose the Bayes rule for a folded Watson distribution and evaluate its performance through simulation in various scenarios, comparing it with the Bayes rule for the Watson distribution. Finally, we present examples using both simulated and real data available in the literature.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 19