How to get coefficients and their confidence intervals in mixed effects models?

Question

In lm and glm models, I use functions coef and confint to achieve the goal:

m = lm(resp ~ 0 + var1 + var1:var2) # var1 categorical, var2 continuous coef(m) confint(m) 

Now I added random effect to the model - used mixed effects models using lmer function from lme4 package. But then, functions coef and confint do not work any more for me!

> mix1 = lmer(resp ~ 0 + var1 + var1:var2 + (1|var3))                                        # var1, var3 categorical, var2 continuous > coef(mix1) Error in coef(mix1) : unable to align random and fixed effects > confint(mix1) Error: $ operator not defined for this S4 class 

I tried to google and use docs but with no result. Please point me in the right direction.

EDIT: I was also thinking whether this question fits more to https://stats.stackexchange.com/ but I consider it more technical than statistical, so I concluded it fits best here (SO)... what do you think?

Answer 1

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)