[R] problem with logistic regression

[Helene.Dryssens@eleves.polytech-lille.fr]

You're right!!!
Thank you very much!!!!

Selon Peter Dalgaard <p.dalgaard at biostat.ku.dk>:

> Helene.Dryssens at eleves.polytech-lille.fr writes:
> 
> > Hi,
> > 
> > we try to do a logistic regression with the function glm.
> > But we notice that this function don't give the same results as the SAS
> proc
> > catmod (differents estimate given).
> > We try to change the contrast on R system with:
> > > options(contrasts=c(unordered="contr.SAS",ordered="contr.poly"))
> > 
> > We also try with brlr and logistf functions.
> > Unfortunately, the estimate aren't still the same.
> 
> contr.SAS is something of a contradiction in terms since SAS does not
> use the same type of contrast in all procedures. I believe PROC CATMOD
> is using sum contrasts (contr.sum), whereas contr.SAS gives you
> something similar to PROC GENMOD (last level set to zero).
> 
> -- 
>    O__  ---- Peter Dalgaard             Blegdamsvej 3  
>   c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
>  (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
> 
>