Tagged Questions
0
votes
0answers
61 views
covariance estimate is zero for random compoment
My dataset consists of 4 variable: values, dil, exp and sample. There are 170 values obtained for variable values; there are 5 levels for the variable "dil", 10 levels for the variable "exp" and 5 ...
6
votes
2answers
591 views
In practice how is the random effects covariance matrix calculated in a mixed effects model?
Basically what I'm wondering is how different covariance structures are enforced, and how the values inside these matrices are calculated. Functions like lme() allow us to chose which structure we'd ...
