sorry, RT had an error in raw data and was treated as a factor. after correction of the raw data (RT is numeric) now it works fine.
thanks a lot christoph > --- Ursprüngliche Nachricht --- > Von: Douglas Bates <[EMAIL PROTECTED]> > An: Christoph Lehmann <[EMAIL PROTECTED]> > Kopie: [email protected] > Betreff: Re: [R] lme model: Error in MEEM > Datum: Thu, 18 Aug 2005 08:29:52 -0500 > > On 8/18/05, Christoph Lehmann <[EMAIL PROTECTED]> wrote: > > Hi, > > We have data of two groups of subjects: 32 elderly, 14 young adults. for > > each subject we have 15 observations, each observation consisting of a > > reaction-time measure (RT) and an activation maesure (betadlpcv). > > since we want to analyze the influence of (age-)group and RT on the > > activation, we call: > > > > lme(betadlpcv ~ RT*group, data=our.data, random=~ RT |subject) > > > > this yields: > > Error in MEEM(object, conLin, control$niterEM) : > > Singularity in backsolve at level 0, block 1 > > In addition: Warning message: > > Fewer observations than random effects in all level 1 groups in: > > lme.formula(betadlpcv ~ RT * group, data = patrizia.data, random = ~RT | > > > > what's the problem here? > > It seems that you only have one observation per subject and you are > trying to estimate a model with two random effects per subject plus > the per-observation noise term. These terms are completely > confounded. > > > > thanks for your kind help > > christoph > > > > -- > > Lust, ein paar Euro nebenbei zu verdienen? Ohne Kosten, ohne Risiko! > > Satte Provisionen für GMX Partner: http://www.gmx.net/de/go/partner > > > > > > > > ______________________________________________ > > [email protected] mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > > > > -- ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
