CircSpaceTime: an R package for spatial and spatio-temporal modeling of Circular data

TL;DR

CircSpaceTime is an R package that provides Bayesian models for spatial and spatio-temporal interpolation of circular data, such as wind directions, using Gaussian processes and hierarchical modeling.

Contribution

It is the first R package to implement Bayesian geostatistical models for circular data, integrating wrapping and projection methods with efficient MCMC inference.

Findings

Successfully applied to wind direction datasets in Italy.

Provides improved, user-friendly implementation over previous research routines.

Enables analysis of spatial and spatio-temporal circular data within a Bayesian framework.

Abstract

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 applications where, among the many, wind directions, animal movement directions, and wave directions are involved. To analyze such data we need models for observations at locations s and times t, as the so-called geostatistical models, providing structured dependence assumed to decay in distance and time. The approach we take begins with Gaussian processes defined for linear variables over space and time. Then, we use either wrapping or projection to obtain processes for circular data. The models are cast as hierarchical, with fitting and inference within a Bayesian framework. Altogether, this package implements work developed by a series of papers; the most relevant being Jona Lasinio, Gelfand, and Jona Lasinio (2012); Wang and Gelfand (2014); Mastrantonio, Jona Lasinio, and Gelfand (2016). All procedures are written using Rcpp. Estimates are obtained by MCMC allowing parallelized multiple chains run. The implementation of the proposed models is considerably improved on the simple routines adopted in the research papers. As original running examples, for the spatial and spatio-temporal settings, we use wind directions datasets over central Italy.