about warning "In mer_finalize(ans) : singular convergence (7)"
On Thu, Feb 9, 2012 at 11:08 AM, Toni Hernandez-Matias
<ahmatias at gmail.com> wrote:
Dear all,
I am trying to fit a set of models with lmer function. My aim is to investigate the relationship between the abundance of a mammal species (count) and several environmental variables. The sample size is 648, but the observations are not independent and the random effect is nested: I have 10 study areas, within each area I performed 6 transects. I have 9-10 observations in all transects. So an example of a model with a single independent variable is: mod05<-lmer(cagaders~E_arb_alt+(1|ter)+(1|ter:trans),data=conill,family=poisson)
When running this model I get the warning: In mer_finalize(ans) : singular convergence (7)
Try using verbose=TRUE to determine where the parameter values are going during the iterative optimization process. If your data could be made available, even in an anonymized form, we could check the model fit against other optimizers that may be more successful.
I don't see an apparent reason for this warning. I would be very grateful if someone can help me to solve this problem and to know wether the results in the fitted model are credible. Thank you very much in advance, Toni -- ********************************************************* Antonio Hernandez Matias Departament de Biologia Animal (Vertebrats) Facultat de Biologia Universitat de Barcelona Av. Diagonal, 645 Barcelona ? ? ?08028 Spain Telephone: +34-934035857 FAX: +34-934035740 e-mail: ahernandezmatias at ub.edu *********************************************************** ? ? ? ?[[alternative HTML version deleted]]
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