Saved in:
Bibliographic Details
Main Authors: Chen, Yang, Fuh, Cheng-Der, Kao, Chu-Lan Michael
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2405.12343
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929423578562560
author Chen, Yang
Fuh, Cheng-Der
Kao, Chu-Lan Michael
author_facet Chen, Yang
Fuh, Cheng-Der
Kao, Chu-Lan Michael
contents Hidden Markov models (HMM) have been widely used by scientists to model stochastic systems: the underlying process is a discrete Markov chain and the observations are noisy realizations of the underlying process. Determining the number of hidden states for an HMM is a model selection problem, which is yet to be satisfactorily solved, especially for the popular Gaussian HMM with heterogeneous covariance. In this paper, we propose a consistent method for determining the number of hidden states of HMM based on the marginal likelihood, which is obtained by integrating out both the parameters and hidden states. Moreover, we show that the model selection problem of HMM includes the order selection problem of finite mixture models as a special case. We give rigorous proof of the consistency of the proposed marginal likelihood method and provide an efficient computation method for practical implementation. We numerically compare the proposed method with the Bayesian information criterion (BIC), demonstrating the effectiveness of the proposed marginal likelihood method.
format Preprint
id arxiv_https___arxiv_org_abs_2405_12343
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Determine the Number of States in Hidden Markov Models via Marginal Likelihood
Chen, Yang
Fuh, Cheng-Der
Kao, Chu-Lan Michael
Statistics Theory
Methodology
Hidden Markov models (HMM) have been widely used by scientists to model stochastic systems: the underlying process is a discrete Markov chain and the observations are noisy realizations of the underlying process. Determining the number of hidden states for an HMM is a model selection problem, which is yet to be satisfactorily solved, especially for the popular Gaussian HMM with heterogeneous covariance. In this paper, we propose a consistent method for determining the number of hidden states of HMM based on the marginal likelihood, which is obtained by integrating out both the parameters and hidden states. Moreover, we show that the model selection problem of HMM includes the order selection problem of finite mixture models as a special case. We give rigorous proof of the consistency of the proposed marginal likelihood method and provide an efficient computation method for practical implementation. We numerically compare the proposed method with the Bayesian information criterion (BIC), demonstrating the effectiveness of the proposed marginal likelihood method.
title Determine the Number of States in Hidden Markov Models via Marginal Likelihood
topic Statistics Theory
Methodology
url https://arxiv.org/abs/2405.12343