Hi R-users: New to R and I am trying to run a GLM with random effects.
I have 3 replicates ('Replicate) of counts of parasites ('nor.tot.lep') before and after an experiment ('In.Out'). When I run lmer I get the error messages (16 of each) below... > lmer(nor.tot.lep ~ In.Out + (In.Out|Replicate),data=coho, family =tweedie(var.power = 1, + link.power = 1)) Generalized linear mixed model fit using PQL Formula: nor.tot.lep ~ In.Out + (In.Out | Replicate) Data: coho Family: Tweedie(mu^1 link) AIC BIC logLik deviance 849.2 867.4 -419.6 839.2 Random effects: Groups Name Variance Std.Dev. Corr Replicate (Intercept) 0.78861 0.88804 In.Out 0.67232 0.81995 -1.000 Residual 2.96308 1.72136 number of obs: 279, groups: Replicate, 3 Fixed effects: Estimate Std. Error t value (Intercept) -0.2431 0.6619 -0.3672 In.Out 1.6004 0.5645 2.8349 Correlation of Fixed Effects: (Intr) In.Out -0.975 There were 30 warnings (use warnings() to see them) > warnings() Warning messages: 1: Estimated variance-covariance for factor ‘Replicate’ is singular in: LMEopt(x = mer, value = cv) 2: nlminb returned message false convergence (8) in: LMEopt(x = mer, value = cv) I have made sure I have the latest lme4 version, any help would be much appreciated. Cheers, Brendan Connors Behavioural Ecology Research Group ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.