[R-sig-ME] LME Question

[Hugo.Mildenberger at web.de]

On Mon, 18 Feb 2013 16:13:07 +0000 John Michel <jwmichel at loyola.edu> wrote:
> I am trying to run a linear mixed effects model on some data I have. My participants are nested within 27 organizations so I have to control for this group. I have  three dependent variables (sales, tips, and employee performance) when I attempt to calculate the null model for these three DVs I get the following error message below:
 
> > Null.SALES<-lme(SALES~1,random=~1|GROUP,data=tccbtips)
> Error in `rownames<-`(`*tmp*`, value = rownames(Fitted) <- origOrder) :
>   attempt to set rownames on object with no dimensions
> In addition: Warning message:
> In Ops.factor(y[revOrder], Fitted) : - not meaningful for factors

Is SALES possibly also a factor?