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Hello all, I was wonder if anyone is aware of an R package with random effect Tobit. Any help would be greatly appreciated. Best, Hedyeh Ahmadi, Ph.D. Statistician Keck School of Medicine Department of Preventive Medicine University of Southern...

Hello all, I'm running a glmer model and I'm getting a "stack imbalance" warning. When I searched for explanations, it looks like it's a programing bug. Here is a link with some information (that might be relevant...

Hello all, I am looking for an R package that can implement multi-level finite mixture models with more than 2 levels (at least 3 levels). I know flexmix() can implement repeated measure but that's about it. Any suggestions...

Hello All, I have used the option nAGQ=0 in many of lme models and I have read about it, my understanding is that the difference between the default, which nAGQ=1 vs nAGQ=0 is the estimation process in...

Hello All, I was wondering if there is a way to implement t-distribution assumption instead of family ="Gaussian" assumption in the lmer() function. I am asking since I have been seeing heavy tails in my outcomes and it shows...

Hello all, I have the following two questions: 1. If one is using a glmer() model with the nAGQ=0 option, I was wondering if there is a way to see if the model has actually converged? 2. If the...

Hi All, I'm looking for a resource and/or advice for GLMM with logit link assumption checking. I understand that Normality assumption of random effects, over-dispersion, and checking the appropriateness of the chosen link need to be checked...

Hello All, I would like to double check my understanding with the followings: 1 - In a linear mixed model if I use ns() for a continuous variable with for example one knot then I'll have two pieces of natural...

Hi All, I was wondering what would be a powerful package in R to run GLMM with logit link that can handle a data set with N=22945 and 3 nested random intercepts. So far, I have tried glmer() from...

Hello all, I'm running a glmer() model with 3 levels where individuals are nested within 21 sites and each individual has 1 to 2 repeated measures. My model has the random effect structure (1|site/subjet_id). So I...

Hi All, I am having a basic question about data formatting for lmer()/glmer() that I think I know the answer, but I would appreciate it if you could confirm my understanding. In the lmer() world, we have either time...

Hello all, I have two questions regarding GLMM with binomial/logit link. Here are some information about my model/data before I ask my questions: * My outcome is 0/1. * I have continuous and categorical predictor. * My data has 19000...

Hi all, I am running a glmer() with Gamma distribution and identity link. The R output is as follows. I would like to check the constant coefficient of variation assumption in R but I am not sure where to start...

Hello All, I am running a lmer() model as follows. The following model gives all the interactions for before and after knots shown below. I have 3 questions: 1. I would like to suppress the highlighted interactions that is before...

Hi All, This email is from an old chain which was giving me issues due to large email size, so I am starting over here to answer some of the questions + add some explanations. I am running a GLMM with...

Thank you Thierry! That was it... Best, Hedyeh Ahmadi, Ph.D. Statistician Keck School of Medicine Department of Preventive Medicine University of Southern California LinkedIn www.linkedin.com/in/hedyeh-ahmadi<http://www.linkedin.com/in/hedyeh-ahmadi> <http://www...

Thank you for the quick and informative reply. Best, Hedyeh Ahmadi, Ph.D. Statistician Keck School of Medicine Department of Preventive Medicine University of Southern California LinkedIn www.linkedin.com/in/hedyeh-ahmadi<http://www.linkedin.com/in/hedyeh-ahmadi...

Just a clarification, when I say "third degree polynomial" I mean, it generates a basis matrix for representing the family of piecewise-cubic splines with the specified sequence of interior knots, and the natural boundary conditions. Best, Hedyeh Ahmadi, Ph...

I'll think more about how to share a data set that would create the same error. Sorry, I am not very simulation savvy but I'll try harder next time. On the bright side, I was able to run...