Dear Emma, Have you tried a simpler model? False convergence can be due to an overcomplex model. Can you give a brief outline of your data? E.g. how many sites, how many data per site, ... Cross tabulations of all pairs of factor variables are usefull too.
HTH, Thierry ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 thierry.onkel...@inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey -----Oorspronkelijk bericht----- Van: Emma Stone [mailto:emma.st...@bristol.ac.uk] Verzonden: vrijdag 13 maart 2009 10:50 Aan: ONKELINX, Thierry; Emma Stone; r-help@r-project.org Onderwerp: RE: [R] Mixed models fixed effects Hi Thierry, That's great thanks! I have done as you have said but I keep getting a warning message here is my code: G1Hvol<-glmer(passes~hvolume+style+habitat(1|Site),family = poisson) And this is the message i get: Warning message: In mer_finalize(ans) : false convergence (8) any ideas?? Emma --On 11 March 2009 15:45 +0100 "ONKELINX, Thierry" <thierry.onkel...@inbo.be> wrote: > Hi Emma, > > Continuous predictors are no problem at all. You can mix both continuous > and categorial predictors if needed. I suppose your response are counts > (the number of bats that passes)? In that case a generalised linear > mixed model is more appropriate. With the lme4 package you could try > something like this: > > library(lme4) > Model <- glmer(BatPasses ~ Width + Height + (1|Site), family = poisson) > > HTH, > > Thierry > > PS There is a mailing list dedicated to mixed models: R-Sig-MixedModels > ------------------------------------------------------------------------ > ---- > ir. Thierry Onkelinx > Instituut voor natuur- en bosonderzoek / Research Institute for Nature > and Forest > Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, > methodology and quality assurance > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > tel. + 32 54/436 185 > thierry.onkel...@inbo.be > www.inbo.be > > To call in the statistician after the experiment is done may be no more > than asking him to perform a post-mortem examination: he may be able to > say what the experiment died of. > ~ Sir Ronald Aylmer Fisher > > The plural of anecdote is not data. > ~ Roger Brinner > > The combination of some data and an aching desire for an answer does not > ensure that a reasonable answer can be extracted from a given body of > data. > ~ John Tukey > > -----Oorspronkelijk bericht----- > Van: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > Namens Emma Stone > Verzonden: woensdag 11 maart 2009 15:29 > Aan: r-help@r-project.org > Onderwerp: Re: [R] Mixed models fixed effects > > Dear All, > > This may sound like a dumb question but I am trying to use a mixed model > to > determine the predictors of bat activity along hedges within 8 sites. So > my > response is continuous (bat passes) my predictors fixed effects are > continuous (height metres), width (metres) etc and the random effect is > site - can you tell me if the fixed effects can be continuous as all > the > examples I have read show them as categorical, but this is not covered > in > any documents I can find. > > Help! > > Emma > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver > weer en binden het INBO onder geen enkel beding, zolang dit bericht niet > bevestigd is door een geldig ondertekend document. The views expressed in > this message and any annex are purely those of the writer and may not be > regarded as stating an official position of INBO, as long as the message > is not confirmed by a duly signed document. ---------------------- Emma Stone Postgraduate Researcher Bat Ecology and Bioacoustics Lab & Mammal Research Unit School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG Email: emma.st...@bristol.ac.uk Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is door een geldig ondertekend document. The views expressed in this message and any annex are purely those of the writer and may not be regarded as stating an official position of INBO, as long as the message is not confirmed by a duly signed document. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
