[R] Converting PROC NLMIXED code to NLME

[Bernardo Rangel Tura]

At 20:40 7/10/2005, Singh, Jatinder wrote:
>NLME
>********
>kidney.nlme<-nlme(model=rtime~
>(event*
>((b1*age+b2*sex+b3*gn+b4*an+b5*pkn+u)+log(delta)+log(gamma)+(gamma-1)*lo
>g(rtime))
>+((-exp(b1*age+b2*sex+b3*gn+b4*an+b5*pkn+u))*delta*(rtime**gamma))
>),
>fixed=list(delta~1,gamma~1,b1~1,b2~1,b3~1,b4~1,b5~1),
>random=u~1|patient,
>start=c(delta=0.03,gamma=1.1,b1=-0.003,b2=-1.2,b3=0.09,b4=0.35,b5=-1.43)
>,
>data=(kidney),
>method="ML",
>na.action=na.include
>)

Hi!

Try change "na.action=na.include" for "na.action=na.omit"

The singularity occurs because the fixed effects matrix is not of full rank 
due to the unused factor levels.




Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil 


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