Graphs are an intuitive way to represent relationships between variables in fields such as finance and neuroscience. However, these graphs often need to be inferred from data. In this paper, we propose a novel framework to infer a latent graph by treating the observed multidimensional data as graph-referenced stationary signals. Specifically, we introduce the graphical autoregressive model (GAR), where the inverse covariance matrix of the observed signals is expressed as a second-order polynomial of the normalized graph Laplacian of the latent graph. The GAR model extends the autoregressive model from time series analysis to general undirected graphs, offering a new approach to graph inference. To estimate the latent graph, we develop a three-step procedure based on penalized maximum likelihood, supported by theoretical analysis and numerical experiments. Simulation studies and an application to S&P 500 stock price data show that the GAR model can outperform Gaussian graphical models when it fits the observed data well. Our results suggest that the GAR model offers a promising new direction for inferring latent graphs across diverse applications. Codes and example scripts are available at https://github.com/jed-harwood/SGM .
Penalized EM algorithm and copula skeptic graphical models for inferring networks for mixed variables
本文研究了高斯copula图模型中稀疏精度矩阵的估计方法,对连续变量、二元变量、计数变量和离散序变量的网络进行重构。我们提出两种方法:$\ell_1$用Monte Carlo期望最大化算法(copula EM glasso)惩罚扩展秩似然,用copula Gaussian图模型的成对copula估计惩罚copula怀疑。所提出的方法有助于推断网络所产生的非正态和混合变量。我们通过对乳腺癌基因组和临床数据以及玉米遗传学数据的模拟研究和分析来证明我们的方法的性能。
Graphical models have been used extensively for modeling brain connectivity networks. However, unmeasured confounders and correlations among measurements are often overlooked during model fitting, which may lead to spurious scientific discoveries. Motivated by functional magnetic resonance imaging (fMRI) studies, we propose a novel method for constructing brain connectivity networks with correlated replicates and latent effects. In a typical fMRI study, each participant is scanned and fMRI measurements are collected across a period of time. In many cases, subjects may have different states of …
A causal vector autoregressive (CVAR) model is introduced for weakly stationary multivariate processes, combining a recursive directed graphical model for the contemporaneous components and a vector autoregressive model longitudinally. Block Cholesky decomposition with varying block sizes is used to solve the model equations and estimate the path coefficients along a directed acyclic graph (DAG). If the DAG is decomposable, i.e. the zeros form a reducible zero pattern (RZP) in its adjacency matrix, then covariance selection is applied that assigns zeros to the corresponding path coefficients. …
Autoregressive with Slack Time Series Model for Forecasting a Partially-Observed Dynamical Time Series
The Institute of Statistical Mathematics(统计数理研究所);RIKEN Center for Advanced Intelligence Project(理化学研究所先进智能项目中心);Kyoto University(京都大学);Hitotsubashi University(一桥大学)
For multivariate stationary time series many important properties, such as partial correlation, graphical models and autoregressive representations are encoded in the inverse of its spectral density matrix. This is not true for nonstationary time series, where the pertinent information lies in the inverse infinite dimensional covariance matrix operator associated with the multivariate time series. This necessitates the study of the covariance of a multivariate nonstationary time series and its relationship to its inverse. We show that if the rows/columns of the infinite dimensional covariance …
We consider the problem of inferring the conditional independence graph (CIG) of a high-dimensional stationary multivariate Gaussian time series. A sparse-group lasso based frequency-domain formulation of the problem has been considered in the literature where the objective is to estimate the sparse inverse power spectral density (PSD) of the data. The CIG is then inferred from the estimated inverse PSD. In this paper we investigate use of a sparse-group log-sum penalty (LSP) instead of sparse-group lasso penalty. An alternating direction method of multipliers (ADMM) approach for iterative opt…
Low-rank bilinear autoregressive models for three-way criminal activity tensors
International Institute for Applied Systems Analysis(国际应用系统分析研究所);Millennium Nucleus on Criminal Complexity and School of Economics and Business, Universidad Alberto Hurtado(阿尔贝托·乌尔塔多大学犯罪复杂性千年核心与经济与商业学院);Department of Decision Sciences and Bocconi Institute for Data Science and Analytics, Bocconi University(博科尼大学决策科学系与博科尼数据科学与分析研究所);Department of Economics, Cornell University(康奈尔大学经济学系)
Identifiability in Graphical Discrete Lyapunov Models
University of Copenhagen(哥本哈根大学);Technical University of Munich(慕尼黑工业大学);Aalto University(阿尔托大学);Technical University of Berlin(柏林工业大学);Worcester Polytechnic Institute(伍斯特理工学院);University of British Columbia(不列颠哥伦比亚大学)
Understanding the dynamics of functional brain connectivity patterns using noninvasive neuroimaging techniques is an important focus in human neuroscience. Vector autoregressive (VAR) processes and Granger causality analysis (GCA) have been extensively used for this purpose. While high-resolution multi-subject neuroimaging data are routinely collected now-a-days, the statistics literature on VAR models has remained heavily focused on small-to-moderate dimensional problems and single-subject data. Motivated by these issues, we develop a novel Bayesian random effects panel VAR model for multi-su…
Polytechnique Montreal(蒙特利尔综合理工学院);McGill University(麦吉尔大学);Interuniversity Research Centre on Enterprise Networks, Logistics and Transportation (CIRRELT)(校际企业网络、物流与交通研究中心(CIRRELT))
Large-scale and multidimensional spatiotemporal data sets are becoming ubiquitous in many real-world applications such as monitoring urban traffic and air quality. Making predictions on these time series has become a critical challenge due to not only the large-scale and high-dimensional nature but also the considerable amount of missing data. In this paper, we propose a Bayesian temporal factorization (BTF) framework for modeling multidimensional time series -- in particular spatiotemporal data -- in the presence of missing values. By integrating low-rank matrix/tensor factorization and vecto…
Graphical models have long been studied in statistics as a tool for inferring conditional independence relationships among a large set of random variables. The most existing works in graphical modeling focus on the cases that the data are Gaussian or mixed and the variables are linearly dependent. In this paper, we propose a double regression method for learning graphical models under the high-dimensional nonlinear and non-Gaussian setting, and prove that the proposed method is consistent under mild conditions. The proposed method works by performing a series of nonparametric conditional indep…
This article is motivated by studying the interaction of magnetic moments in high entropy alloys (HEAs), which plays an important role in guiding HEA designs in materials science. While first principles simulations can capture magnetic moments of individual atoms, explicit models are required to analyze their interactions. This is essentially an inverse covariance matrix estimation problem. Unlike most of the literature on graphical models, the inverse covariance matrix possesses inherent structural constraints encompassing node types, topological distance of nodes, and partially specified con…
Neuroimaging is the growing area of neuroscience devoted to produce data with the goal of capturing processes and dynamics of the human brain. We consider the problem of inferring the brain connectivity network from time dependent functional magnetic resonance imaging (fMRI) scans. To this aim we propose the symmetric graphical lasso, a penalized likelihood method with a fused type penalty function that takes into explicit account the natural symmetrical structure of the brain. Symmetric graphical lasso allows one to learn simultaneously both the network structure and a set of symmetries acros…
This paper develops a Bayesian graphical model for fusing disparate types of count data. The motivating application is the study of bacterial communities from diverse high dimensional features, in this case transcripts, collected from different treatments. In such datasets, there are no explicit correspondences between the communities and each correspond to different factors, making data fusion challenging. We introduce a flexible multinomial-Gaussian generative model for jointly modeling such count data. This latent variable model jointly characterizes the observed data through a common multi…
Probabilistic Graphical Model using Graph Neural Networks for Bayesian Inversion of Discrete Structural Component States
Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology(工信部智能防灾减灾重点实验室);Harbin Institute of Technology(哈尔滨工业大学);Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, School of Civil Engineering, Harbin, Institute of Technology(教育部结构动力行为与控制重点实验室,土木工程学院);The Institute of Statistical Mathematics, Research Organization of Information and Systems(统计数学研究所,信息与系统研究机构);The Graduate University for Advanced Studies, SOKENDAI(高等研究大学,SOKENDAI);Division of Engineering and Applied Science, California Institute of Technology(工程与应用科学系,加州理工学院)