lme4
lme4::lmer reports “fixed-effect model matrix is rank deficient”, do I need a fix and how to?
You are slightly over-concerned with the warning message: fixed-effect model matrix is rank deficient so dropping 7 columns / coefficients. It is a warning not an error. There is neither misuse of lmer nor ill-specification of model formula, thus you will obtain an estimated model. But to answer your question, I shall strive to explain … Read more
How to get coefficients and their confidence intervals in mixed effects models?
Not sure when it was added, but now confint() is implemented in lme4. For example the following example works: library(lme4) m = lmer(Reaction ~ Days + (Days | Subject), sleepstudy) confint(m)