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Main Authors: Rodríguez-Vítores, David, Matrán, Carlos
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2302.11487
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author Rodríguez-Vítores, David
Matrán, Carlos
author_facet Rodríguez-Vítores, David
Matrán, Carlos
contents This work introduces a refinement of the Parsimonious Model for fitting a Gaussian Mixture. The improvement is based on the consideration of clusters of the involved covariance matrices according to a criterion, such as sharing Principal Directions. This and other similarity criteria that arise from the spectral decomposition of a matrix are the bases of the Parsimonious Model. We show that such groupings of covariance matrices can be achieved through simple modifications of the CEM (Classification Expectation Maximization) algorithm. Our approach leads to propose Gaussian Mixture Models for model-based clustering and discriminant analysis, in which covariance matrices are clustered according to a parsimonious criterion, creating intermediate steps between the fourteen widely known parsimonious models. The added versatility not only allows us to obtain models with fewer parameters for fitting the data, but also provides greater interpretability. We show its usefulness for model-based clustering and discriminant analysis, providing algorithms to find approximate solutions verifying suitable size, shape and orientation constraints, and applying them to both simulation and real data examples.
format Preprint
id arxiv_https___arxiv_org_abs_2302_11487
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Improving Model Choice in Classification: An Approach Based on Clustering of Covariance Matrices
Rodríguez-Vítores, David
Matrán, Carlos
Methodology
Computation
62H30
G.3
This work introduces a refinement of the Parsimonious Model for fitting a Gaussian Mixture. The improvement is based on the consideration of clusters of the involved covariance matrices according to a criterion, such as sharing Principal Directions. This and other similarity criteria that arise from the spectral decomposition of a matrix are the bases of the Parsimonious Model. We show that such groupings of covariance matrices can be achieved through simple modifications of the CEM (Classification Expectation Maximization) algorithm. Our approach leads to propose Gaussian Mixture Models for model-based clustering and discriminant analysis, in which covariance matrices are clustered according to a parsimonious criterion, creating intermediate steps between the fourteen widely known parsimonious models. The added versatility not only allows us to obtain models with fewer parameters for fitting the data, but also provides greater interpretability. We show its usefulness for model-based clustering and discriminant analysis, providing algorithms to find approximate solutions verifying suitable size, shape and orientation constraints, and applying them to both simulation and real data examples.
title Improving Model Choice in Classification: An Approach Based on Clustering of Covariance Matrices
topic Methodology
Computation
62H30
G.3
url https://arxiv.org/abs/2302.11487