I have a question about linear mixed model fitting in R.
Now I have common model as below
where X and Z are fixed and random effect regressor respectively.
Now all I want to do is using R to fit a linear mixed model. However, I came across problem since my Z is a 100*98 matrix. When I trying to fit it using lme command in R, the random part looks really complicated. Is there any other way to fit such model in R? Could you help and I will be really grateful if you can reply soon. Best regards, Yours faithfully, Victor