A new iterative initialization of EM algorithm for Gaussian mixture models

PLoS One. 2023 Apr 13;18(4):e0284114. doi: 10.1371/journal.pone.0284114. eCollection 2023.

Abstract

Background: The expectation maximization (EM) algorithm is a common tool for estimating the parameters of Gaussian mixture models (GMM). However, it is highly sensitive to initial value and easily gets trapped in a local optimum.

Method: To address these problems, a new iterative method of EM initialization (MRIPEM) is proposed in this paper. It incorporates the ideas of multiple restarts, iterations and clustering. In particular, the mean vector and covariance matrix of sample are calculated as the initial values of the iteration. Then, the optimal feature vector is selected from the candidate feature vectors by the maximum Mahalanobis distance as a new partition vector for clustering. The parameter values are renewed continuously according to the clustering results.

Results: To verify the applicability of the MRIPEM, we compared it with other two popular initialization methods on simulated and real datasets, respectively. The comparison results of the three stochastic algorithms indicate that MRIPEM algorithm is comparable in relatively high dimensions and high overlaps and significantly better in low dimensions and low overlaps.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Cluster Analysis
  • Normal Distribution

Grants and funding

This work was financially supported by Chinese Universities Scientific Fund (Grant Nos. 2452022369 and 2452019546). The funders partially supported the data collection and analysis in this study.