High-Dimensional Covariate-Dependent Discrete Graphical Models and Dynamic Ising Models
Lyndsay Roach, Qiong Li, Nanwei Wang, Xin Gao
TL;DR
This work develops covariate-dependent discrete graphical models to capture time- and covariate-driven changes in dependence among high-dimensional discrete variables, with the dynamic Ising model as a special case. It combines a covariate-modulated log-linear parametrization (baseline and slope graphs) with a likelihood framework, leveraging pseudo-likelihood for scalable high-dimensional parameter estimation and scalable birth-death MCMC (SBDMCM) for structure learning. Theoretical results establish asymptotic normality of estimators, and extensive simulations validate estimation, hypothesis testing, and model selection performance. The authors demonstrate utility on a longitudinal gene-expression dataset related to influenza vaccination, illustrating covariate-driven network changes and offering a principled toolkit for dynamic, discrete networks in genomics and beyond.
Abstract
We propose a covariate-dependent discrete graphical model for capturing dynamic networks among discrete random variables, allowing the dependence structure among vertices to vary with covariates. This discrete dynamic network encompasses the dynamic Ising model as a special case. We formulate a likelihood-based approach for parameter estimation and statistical inference. We achieve efficient parameter estimation in high-dimensional settings through the use of the pseudo-likelihood method. To perform model selection, a birth-and-death Markov chain Monte Carlo algorithm is proposed to explore the model space and select the most suitable model.
