Dear R-Users:

I am trying to find the robust (or sandwich) estimates of the standard error of 
fixed effects parameter estimates using the package "lmer2". In model-1, I used 
"robust=TRUE" on the other, in model-2, I used "robust=FALSE". Both models 
giving me the same estimates. So my question is, does the robust option works 
in lmer2 to get the robust estimates of the standard error? If anybody could 
offer me a suggestion I would greatly appreciate it. Thank you.  

Model-1:

> p.mle<-lmer2(ddimer~race+steroid+psi+sofa+apache + (apache|subject), 
> method="ML", data=final, robust=TRUE, cluster="id", weights=final$w)
> beta=fixef(p.mle)
> Vcov=vcov(p.mle, useScale=FALSE)
> se=sqrt(diag(Vcov))
> beta
 (Intercept)         race      steroid          psi         sofa       apache 
 5.826489820 -0.001920670 -0.242040171  0.005293996  0.075468340  0.009245152 
> se
[1] 0.108325229 0.058921371 0.055975547 0.001285687 0.018119089 0.002559902

Model-2:

> p.mle<-lmer2(ddimer~race+steroid+psi+sofa+apache + (apache|subject), 
> method="ML", data=final, robust=FALSE, cluster="id", weights=final$w)
> beta=fixef(p.mle)
> Vcov=vcov(p.mle, useScale=FALSE)
> se=sqrt(diag(Vcov))
> beta
 (Intercept)         race      steroid          psi         sofa       apache 
 5.826489820 -0.001920670 -0.242040171  0.005293996  0.075468340  0.009245152 
> se
[1] 0.108325229 0.058921371 0.055975547 0.001285687 0.018119089 0.002559902


Best Regards, 

Sattar


      
____________________________________________________________________________________

, and more!

        [[alternative HTML version deleted]]

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to