LINEAR ALGEBRA AND ITS APPLICATIONS, vol.436, no.9, pp.3337-3346, 2012 (SCI-Expanded)
We derive the spectral decomposition of a covariance matrix for the balanced mixed analysis of variance model. The derivation is based on determining the distinct eigenvalues of a covariance matrix and then obtaining a principal idempotent matrix for each distinct eigenvalue. Examples are given to illustrate the results. (C) 2011 Elsevier Inc. All rights reserved.