Mixed models, did someone figure out lme? [R for BE/BA]

posted by ElMaestro  – Belgium?, 2020-08-11 14:42 (44 d 16:25 ago) – Posting: # 21857
Views: 460

Hi d_labes,


» what was the question?

The question is, how to fit a relevant model with lme and how to extract relevant variance components in an easy way? (as in, easier than in the post linked to).


» You may find here some hints for using nlme/lme() in evaluation of replicate cross-over designs.

I read the post many times since you originally posted it :-D
But I am none the wiser even after reading it many times. So, I feel I have an ok understanding of the mixed model, and I have an ok understanding of which variance components I can reasonably ask for; the next step is then to ask lme to get me what I want in an intuitive fashion. That last thing is not easy, and books like Pinheiro & Bates do not really get me there.

For example: I prefer to play with variance components directly without involvement of rho (correlation) for the covariance of T and R. Where do I start? Playing around with weights, correlation structure, etc may get me what I want (see the two threads linkeda above), but that stil does not mean I am using lme meaningfully or optimally, I feel.

I could be wrong, but...

Best regards,
ElMaestro

R's base package has 274 reserved words and operators, along with 1761 functions. I can use 18 of them (about 14 of them properly). I believe this makes me the Donald Trump of programming.

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