[R] LME without convergence

[Ralf Sommerfeld]

Dear R-help list readers,

I am fitting a mixed model using the lme function (R V 2.3.1 for 
Windows). This is an example:

dep<-c(25,40,33.33,60,70.83,72,71.43,50,40,53.33,64,54.17,60,53.57)
yes<-c(0,1,2,3,4,5,6,0,1,2,3,4,5,6)
treat<-c(1,1,1,1,1,1,1,0,0,0,0,0,0,0) #factor

If I now fit a model with random slopes as well as intercepts:

model1<-lme(dep~yes,random=yes|treat)

R encounters the following problem:

Fehler in lme.formula(dep ~ yes, random = ~yes | treat) :
         iteration limit reached without convergence (9)

Following other instructions on that problem, I tried to adjust the 
iteration limits and tolerances using lmeControl(), however this did not 
work.

Can someone help me?

Best regards,
Ralf