[R] sas vs r

[Henric Nilsson]

At 05:24 2004-04-28, Liliana Forzani wrote:

>I have a code in sas (NLMIXED) and I have a hard time converting to r
>1)it is poisson, with random intercept, but
>it have an offset.  Means, I do not want one of the coefficient to be
>estimate. Means, may model is
>g(mean) = beta X + Z,
>Z fixed, X fixed and beta to be estimate
>I am using glmmML.

If I recall correctly, neither glmmML nor glmmPQL (from MASS) handles 
offset terms. But GLMM in the lme4 package does.

>2) the same but I have random slope (and I think with glmmML I can use
>only random intercept)

GLMM in lme4 can do this.

>3) I try to use nlme, is this "equivalent" to NLMIXED?

No, nlme fits non-linear and linear mixed-effect models with Gaussian error 
terms.

I hope this helps,
Henric