Ontology highlight
ABSTRACT:
SUBMITTER: Zhang G
PROVIDER: S-EPMC3836449 | biostudies-literature | 2013
REPOSITORIES: biostudies-literature
Zhang Guangxiang G Chen John J JJ
Journal of statistical computation and simulation 20130101 12
Linear mixed-effects model has been widely used in longitudinal data analyses. In practice, the fitting algorithm can fail to converge due to boundary issues of the estimated random-effects covariance matrix G, i.e., being near-singular, non-positive definite, or both. Current available algorithms are not computationally optimal because the condition number of matrix G is unnecessarily increased when the random-effects correlation estimate is not zero. We propose an adaptive fitting (AF) algorit ...[more]