QUT ePrints

Variational Bayes and the reduced dependence approximation for the autologistic model on an irregular grid with applications

McGrory, Clare A., Pettitt, Anthony N., Reeves, Robert, Griffin, Mark, & Dwyer, Mark (2011) Variational Bayes and the reduced dependence approximation for the autologistic model on an irregular grid with applications. Journal of Computational and Graphical Statistics.

View at publisher

Abstract

Discrete Markov random field models provide a natural framework for representing images or spatial datasets. They model the spatial association present while providing a convenient Markovian dependency structure and strong edge-preservation properties. However, parameter estimation for discrete Markov random field models is difficult due to the complex form of the associated normalizing constant for the likelihood function. For large lattices, the reduced dependence approximation to the normalizing constant is based on the concept of performing computationally efficient and feasible forward recursions on smaller sublattices which are then suitably combined to estimate the constant for the whole lattice. We present an efficient computational extension of the forward recursion approach for the autologistic model to lattices that have an irregularly shaped boundary and which may contain regions with no data; these lattices are typical in applications. Consequently, we also extend the reduced dependence approximation to these scenarios enabling us to implement a practical and efficient non-simulation based approach for spatial data analysis within the variational Bayesian framework. The methodology is illustrated through application to simulated data and example images. The supplemental materials include our C++ source code for computing the approximate normalizing constant and simulation studies.

Impact and interest:

0 citations in Scopus
Search Google Scholar™
0 citations in Web of Science®

Citation countsare sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 48770
Item Type: Journal Article
Additional Information: Taylor & Francis FirstOnline Publication
Keywords: Variational Bayes, Discrete Markov Random Field Modeling, Reduced Dependence Approximation, Bayesian analysis, Image analysis, Spacial Data
DOI: 10.1080/10618600.2012.632232
ISSN: 1537-2715
Subjects: Australian and New Zealand Standard Research Classification > MATHEMATICAL SCIENCES (010000) > STATISTICS (010400) > Applied Statistics (010401)
Divisions: Current > QUT Faculties and Divisions > Division of Technology, Information and Learning Support
Current > Research Centres > High Performance Computing and Research Support
Current > Schools > School of Mathematical Sciences
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Deposited On: 22 Feb 2012 08:00
Last Modified: 22 Feb 2012 08:00

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page