[R-sig-ME] Error in MEEM(object, conLin, control$niterEM) : Singularity in backsolve at level 0, block 1 in LME model

[Arivoara Rabarijaona]

Thank you for your explanation. I really appreciate it.
However, there is no change using nlme (Error in MEEM(object, conLin,
control$niterEM) : Singularity in backsolve at level 0, block 1 in LME
model) and lmer (fixed-effect model matrix is rank deficient so dropping 6
columns / coefficients). My problem is not resolved.
There is a problem with repetition only when I use lmer model.

Arivoara Rabarijaona

Le mer. 7 juil. 2021 à 16:26, Ben Bolker <bbolker using gmail.com> a écrit :

>    You have constructed a model with multicollinear predictors (another
> way to put this is that your model matrix is rank-deficient).  R's
> formula interface usually takes care of discarding redundant columns,
> but when interactions are spelled out explicitly with it can't always
> manage. You might do better expressing the fixed effects component of
> the model as
>
> (provenance + treatment + status)^2
> '
> As is often stated in this forum, you may have trouble fitting a random
> effect with only four levels (repetition).
>
>    Ben Bolker
>
> On 7/7/21 4:01 AM, Arivoara Rabarijaona wrote:
> > Thank you,
> > provenance:treatment is normal, nothing is unexpected
> > I think the problem is with provenance:status, but I don't know how to
> > resolve it.
> > Using lmer, I get the message: fixed-effect model matrix is rank
> deficient
> > so dropping 18 columns / coefficients
> >
> > Ari
> >
> > Le mer. 7 juil. 2021 à 09:52, romunov <romunov using gmail.com> a écrit :
> >
> >> Have you tried plotting this? My guess is that you will find something
> >> unexpected in the provenance:treatment level combination.
> >>
> >> Cheers,
> >> Roman
> >>
> >> On Wed, Jul 7, 2021 at 9:03 AM Arivoara Rabarijaona <arivoara using gmail.com
> >
> >> wrote:
> >>
> >>> Hi,
> >>> I hope someone can help me. I'm using nlme to fit models.
> >>>
> >>> My dataframe (1785 obs) :
> >>> $ id: Factor w/595 levels
> >>> $ treatment: Factor w/3 levels
> >>> $ provenance: Factor w/16 levels
> >>> $ repetition: Factor w/4 levels
> >>> $ bloc: Factor w/66 levels # nested to repetition
> >>> $ response: num ... (1777 obs and 8 NA) # 3 repeated measures by id
> >>> $ status: Factor w/3 levels, "dominant","codominant","suppressed" #
> there
> >>> are 6 provenances without suppressed trees
> >>>
> >>> I want to run a modele like this :
> >>>
> >>> modele <- lme(response  ~ provenance + treatment +
> provenance:treatment +
> >>> status + status:treatment + statuts:provenance,
> >>>                     random = ~ 1|repetition/bloc,
> >>>                     correlation = corAR1(form = ~
> 1|repetition/bloc/id),
> >>>                     data, method= "ML", na.action =na.omit)
> >>>
> >>> I get the message :
> >>> Error in MEEM(object, conLin, control$niterEM) :   Singularity in
> >>> backsolve
> >>> at level 0, block 1 in LME model
> >>>
> >>> If I run the modele without the interaction statuts:provenance, it
> works.
> >>>
> >>> Can anyone tell me how to resolve this error ?
> >>>
> >>> Thanks,
> >>> Arivoara Rabarijaona
> >>>
> >>>          [[alternative HTML version deleted]]
> >>>
> >>> _______________________________________________
> >>> R-sig-mixed-models using r-project.org mailing list
> >>> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
> >>>
> >>
> >>
> >> --
> >> In God we trust, all others bring data.
> >>
> >
> >       [[alternative HTML version deleted]]
> >
> > _______________________________________________
> > R-sig-mixed-models using r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
> >
>
> _______________________________________________
> R-sig-mixed-models using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
>

	[[alternative HTML version deleted]]