[R-sig-ME] warnings ranef and design of a binomial model

[Robert ESPESSER]

> ----------------------------------------
> From: Douglas Bates <bates at stat.wisc.edu>
> Sent: Wed Sep 10 15:43:38 CEST 2008
> To: Robert ESPESSER <Robert.Espesser at lpl-aix.fr>
> Subject: Re: [R-sig-ME] warnings ranef and design of a binomial model

>I think we would need at least the output from traceback() to see
>where the error is occurring.  Better yet would be to have access to
>the data so we could try out the model fits.  Sometimes these errors
>show up deep inside another computation.  Does

>ranef(mod.glmer)

>produce a result?  I'm trying to decide if the problem is in the
>postVar part or in the ranef part.


The warning messages are output by dotplot(ranef() ).
ranef(xxx ,postVar=T) by  itself does not output any warning messages. 

The models:
modG.glmer <- glmer( vd ~ dlms*expe  +(dlms|subject) ,family=binomial, ....)
modI.glmer <- glmer( vd ~ dlms*expe  +(1|subject) ,family=binomial, ....)
modS.glmer <- glmer( vd ~ dlms*expe  +(0+dlms|subject) ,family=binomial, ....)

have their dotplot(ranef()) OK. 

The problem is only with the model:
modIS.glmer <-  glmer( vd ~ dlms*expe +(1|subject) +(0+dlms|subject) ,family=binomial, ....)

ranef(modIS.glmer)-> rr.glmer
>  dotplot( rr.glmer)
$subject

Warning messages:
1: In min(x) : aucun argument trouvé pour min ; Inf est renvoyé
2: In max(x) : aucun argument pour max ; -Inf est renvoyé

traceback() returns nothing :
> traceback()
2: bar(2)
1: foo(2)
(because I have tested it with the example in ?traceback)

In addition, how can I extract the postVar component in a ranef object ?
Dr Bates, in case you need the data , do I have attach them in a private mail to you ?

here is the complete sessionInfo():
R version 2.7.2 (2008-08-25) 
i386-pc-mingw32 

locale:
LC_COLLATE=French_France.1252;LC_CTYPE=French_France.1252;LC_MONETARY=French_France.1252;LC_NUMERIC=C;LC_TIME=French_France.1252

attached base packages:
[1] stats     graphics  grDevices datasets  utils     methods   base     

other attached packages:
[1] lme4_0.999375-26   Matrix_0.999375-13 lattice_0.17-13   

loaded via a namespace (and not attached):
[1] grid_2.7.2  nlme_3.1-89





> 
> On Wed, Sep 10, 2008 at 5:29 AM, Robert ESPESSER
> <Robert.Espesser at lpl-aix.fr> wrote:
> > Dear R users,
> >
> > I have a question about model design.
> > One group of 20 subjects run the A experiment, with 17 binary responses by subject.
> > An other group of 20 subjects run the 2 experiments B and C, with 20 binary responses by subject,
> > for both of the 2 experiment.
> >
> > I want to study the effect of the  factor "expe"
> > I tried this covariance model:
> > mod.glmer <-  glmer( vd ~ dlms*expe +(1|subject) +(0+dlms|subject) ,
> >              family=binomial, ....)
> >
> > where:
> > dlms is a numeric factor (-2,-1,0, 1,2)
> > expe is a 3 levels factor , coding the experiment (A or B or C)
> >
> > vd is the success/fail matrix.
> >
> > The model with a random slope is clearly better than an intercept-only model.
> >
> > the results look plausible, ranef(mod.glmer, postVar=T) was OK for the
> > Intercept, but failed
> > to compute the postvar of the random slope , with these warnings:
> > 1: In min(x): no argument found for min; Inf is returned
> > It's the same for max.
> >
> > I'm  suspecting  that my model is perhaps badly designed , concerning the
> > unbalanced repartition of the subjects across the experiments. Is it correct ?
> >
> > Thanks for any comments or suggestions.
> >
> > ####
> > sessionInfo()  is:
> > R version 2.7.2
> >
> > lme4_0.999375-26
> > Matrix_0.999375-13
> >
> >
> > Robert Espesser
> > Laboratoire Parole et Langage  UMR 6057, CNRS
> > 29 Av. Robert Schuman  13621 AIX    (FRANCE)
> > Tel: +33 (0)4 42 95 36 26   Fax: +33 (0)4 42 95 37 88
> > http://www.lpl-aix.fr
> >
> > _______________________________________________
> > R-sig-mixed-models at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
> >
> 
> _______________________________________________
> R-sig-mixed-models at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models