** apologies if this is a duplicate - my email app fell over on 1st 
attempt **

[ running R 2.13.0   on  windows XP ]

I'm trying to find an appropriate mixed model for the following data

'data.frame':   128 obs. of  17 variables:
 $ Study     : Factor w/ 8 levels "8230-443","8230-619",..: 1 1 1 1 1 1 1 
1 1 1 ...
 $ Group     : Factor w/ 2 levels "QC","Vehicle": 1 1 1 1 1 1 1 1 2 2 ...
 $ Label     : Factor w/ 2 levels "log10Cer","log10Hip": 1 2 1 2 1 2 1 2 1 
2 ...
 $ Data      : num  -0.796 -0.453 -0.638 -0.343 -0.526 ...
 $ Subject   : Factor w/ 64 levels "25","26","27",..: 1 1 2 2 3 3 4 4 5 5 
...
 $ Days      : num  508 508 508 508 508 ...
(unused variables excluded from email)

Experimental layout: 

two treatment groups in each of several studies, 
several subjects in each group, with a measurement made 
at each of two specific locations ('h' and 'c') on each subject.:

                                Study.1          Study.2     .....> etc
  QC.Group   :     subject:   q1   q2   q3     q4   q5   q6 
                       label h c  h c  h c    h c  h c  h c
 
Vehicle.Group:     subject:   v1   v2   v3     v4   v5   v6 
                       label h c  h c  h c    h c  h c  h c
 
Study & Group are crossed; subjects are all uniquely numbered; 
Study and subject are both random effects, Group and Label are fixed 
effects.

I've worked through a series of models and seem to be homing-in on the 
following
 
QVHd.H1<-lme4a::lmer(Data ~ Days + Group*Label + 
                     (1|Study) + (0+Group:Label|Subject)  , 
data=QVHd,REML=F)
 
Frustratingly though, when I come to profile the model I get the following 
error ...

> pr1<-profile(QVHd.H1)
Error in rbind2(fillmat(pres, lowcut, zeta, wp1), fillmat(nres, lowcut,  : 

  error in evaluating the argument 'y' in selecting a method for function 
'rbind2': 
Error in bobyqa(start, function(x) dd(mkpar(nvp, w, xx, x)), lower = 
lowvp[-w]) : 
  internal error -4 in R_decompress1
> 

at which point the pc starts to run veeeeery slowly (all applications, not 
just R).

I'd be pathetically grateful for any guidance on where to start to get to 
grips with this ...

        thanks          Bob Kinley
 

 
 

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