Fitting Linear Mixed-Effects Models Using lme4
TLDR
In this article, a model is described in an lmer call by a formula, in this case including both fixed-and random-effects terms, and the formula and data together determine a numerical representation of the model from which the profiled deviance or the profeatured REML criterion can be evaluated as a function of some of model parameters.Abstract:
Maximum likelihood or restricted maximum likelihood (REML) estimates of the parameters in linear mixed-effects models can be determined using the lmer function in the lme4 package for R. As for most model-fitting functions in R, the model is described in an lmer call by a formula, in this case including both fixed- and random-effects terms. The formula and data together determine a numerical representation of the model from which the profiled deviance or the profiled REML criterion can be evaluated as a function of some of the model parameters. The appropriate criterion is optimized, using one of the constrained optimization functions in R, to provide the parameter estimates. We describe the structure of the model, the steps in evaluating the profiled deviance or REML criterion, and the structure of classes or types that represents such a model. Sufficient detail is included to allow specialization of these structures by users who wish to write functions to fit specialized linear mixed models, such as models incorporating pedigrees or smoothing splines, that are not easily expressible in the formula language used by lmer.read more
Citations
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Journal ArticleDOI
Arctic Geese Tune Migration to a Warming Climate but Still Suffer from a Phenological Mismatch.
Thomas K. Lameris,Henk P. van der Jeugd,Götz Eichhorn,Adriaan M. Dokter,Adriaan M. Dokter,Willem Bouten,Michiel P. Boom,Konstantin E. Litvin,Bruno J. Ens,Bart A. Nolet +9 more
TL;DR: By combining multiple years of tracking and reproduction data, this work shows that a long-distance migratory bird (the barnacle goose, Branta leucopsis) accelerates its 3,000 km spring migration to advance arrival on its rapidly warming Arctic breeding grounds.
Journal ArticleDOI
Democracy in times of the pandemic: explaining the variation of COVID-19 policies across European democracies
Sarah Engler,Palmo Brunner,Romane Loviat,Tarik Abou-Chadi,Lucas Leemann,Andreas Glaser,Daniel Kübler +6 more
TL;DR: In this article, the authors examine why some democracies were willing to constrain individual freedoms and concentrate power more than others during the pandemic's first wave, and they find that the strong protection of democratic principles already established in normal times makes governments more reluctant to opt for restrictive policies.
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The Statistical Value of Raw Fluorescence Signal in Luminex xMAP Based Multiplex Immunoassays
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Shifts in plant functional composition following long‐term drought in grasslands
Robert J. Griffin-Nolan,Dana M. Blumenthal,Scott L. Collins,Timothy E. Farkas,Ava M. Hoffman,Kevin E. Mueller,Troy W. Ocheltree,Melinda D. Smith,Kenneth D. Whitney,Alan K. Knapp +9 more
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Linking green infrastructure to urban heat and human health risk mitigation in Oslo, Norway
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References
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TL;DR: Linear Mixed-Effects and Nonlinear Mixed-effects (NLME) models have been studied in the literature as mentioned in this paper, where the structure of grouped data has been used for fitting LME models.
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