A good place to start with all GL(M)M questions is Ben Bolker's FAQ which provides thoughts on many commonly asked questions. In particular http://bbolker.github.io/mixedmodels-misc/glmmFAQ.html#how-do-i-compute-a-coefficient-of-determination-r2-or-an-analogue-for-glmms
An approach I have used in the past (for non-mixed models) is to compare the deviance of a given model to that of the 'full' model (ie maximal time and/or space variation) and the null (intercept only) model - see http://www.cebc.cnrs.fr/publipdf/2008/GBR83.pdf (the FAQ attributes the approach to Xu 2003) Best wishes Rob ***** Check out changes in bird distributions at www.bto.org/mapstore *********** Dr Rob Robinson, Associate Director - Research British Trust for Ornithology, The Nunnery, Thetford, Norfolk, IP24 2PU Ph: +44 (0)1842 750050 T: @btorobrob E: rob.robin...@bto.org W: www.bto.org/about-bto/our-staff/rob-robinson ============ "To go fast, travel alone; to go far, travel together" =========== On 25 January 2018 at 00:15, Diego Podadera <diegopodad...@gmail.com> wrote: > Hi everyone, > > What is the best way to express the goodness of fit for a model obtained > by generalized least squares (using gls function from nlme package)? I > don’t want to compare this model with other models, so AIC is not a good > choice in this case. Is it right to use the approach proposed by NAKAGAWA, > S.; SCHIELZETH, H. A general and simple method for obtaining R2 from > generalized linear mixed-effects models. Methods in Ecology and Evolution, > v. 4, n. 2, p. 133–142, 2013 (rsquared{piecewiseSEM}) to calculate the > marginal squared r even if my model is a simple regression instead a mixed > model? For mixed models we get, in the output, values for marginal and > conditional squared r. For models only with fixed effects we get a value > for only one squared r. > > Cheers, > Diego Sotto Podadera > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-ecology mailing list > R-sig-ecology@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-ecology [[alternative HTML version deleted]] _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
