Bayesian Sphere-on-Sphere Regression with Optimal Transport Maps

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ng, Tin Lok James, Kwong, Kwok-Kun, Liu, Jiakun, Zammit-Mangion, Andrew
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910230308192256
author Ng, Tin Lok James
Kwong, Kwok-Kun
Liu, Jiakun
Zammit-Mangion, Andrew
author_facet Ng, Tin Lok James
Kwong, Kwok-Kun
Liu, Jiakun
Zammit-Mangion, Andrew
contents Spherical regression, in which both covariates and responses lie on the sphere, arises in many scientific applications and has attracted considerable methodological attention in recent years. Despite this progress, constructing flexible and expressive regression models between spherical domains remains challenging, particularly because a single global mapping is often insufficient to capture complex relationships across the entire sphere. A natural strategy is therefore to partition the spherical domain and allow distinct mappings within each region, though this introduces the additional challenge of modeling the partition structure itself. To address these issues, we propose an approach based on optimal transport to model spherical partitions, combined with parametric mappings defined locally within each region. We adopt a Bayesian framework to jointly model both the partitioning and the associated regression maps. This framework enables the identification of heterogeneous regions on the sphere while providing principled uncertainty quantification. Through real-data applications, we demonstrate that the proposed method achieves strong predictive performance, yields meaningful uncertainty estimates, and reveals interpretable clustering structure in spherical data.
format Preprint
id arxiv_https___arxiv_org_abs_2501_08492
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bayesian Sphere-on-Sphere Regression with Optimal Transport Maps
Ng, Tin Lok James
Kwong, Kwok-Kun
Liu, Jiakun
Zammit-Mangion, Andrew
Methodology
Statistics Theory
Spherical regression, in which both covariates and responses lie on the sphere, arises in many scientific applications and has attracted considerable methodological attention in recent years. Despite this progress, constructing flexible and expressive regression models between spherical domains remains challenging, particularly because a single global mapping is often insufficient to capture complex relationships across the entire sphere. A natural strategy is therefore to partition the spherical domain and allow distinct mappings within each region, though this introduces the additional challenge of modeling the partition structure itself. To address these issues, we propose an approach based on optimal transport to model spherical partitions, combined with parametric mappings defined locally within each region. We adopt a Bayesian framework to jointly model both the partitioning and the associated regression maps. This framework enables the identification of heterogeneous regions on the sphere while providing principled uncertainty quantification. Through real-data applications, we demonstrate that the proposed method achieves strong predictive performance, yields meaningful uncertainty estimates, and reveals interpretable clustering structure in spherical data.
title Bayesian Sphere-on-Sphere Regression with Optimal Transport Maps
topic Methodology
Statistics Theory
url https://arxiv.org/abs/2501.08492