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Error en mer_finalize(ans) : Downdated X'X is not positive definite, 1. What is wrong with my model?

Ben Bolker · 2013-03-04T13:24:19Z

PALACIO BLASCO, SARA writes: [snip] > I am trying to run the following model in glmer: > > > M_bud_type1=glmer(Dead~Treatment* fBud_type + fBud_type:Species + > > (1|fRep), family=binomial, data=species) > > where: > - Dead is a binomial response variable > - fBud_type is a fixed factor with 3 levels > - Species is a fixed factor with 9 levels nested within fBud_type and > - fRep is a random factor with 27 levels nested within Species > > I have 1386 observations. > The

Ben Bolker

Mon, Mar 4, 2013 5:24 AM

PALACIO BLASCO, SARA <s.palacio at ...> writes:

[snip]

Did you already read the http://glmm.wikidot.com/faq#errors section?

  It sounds like all your predictors are categorical (although we don't
know about Treatment), so centering isn't really as important/as practical
an option (you can use sum-to-zero contrasts, but it probably won't
make a big difference).

  Ben Bolker

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