Re: [R] GLM quasipoisson error
atorso wrote: Hello, I'm having an error when trying to fit the next GLM: model-glm(response ~ CLONE_M + CLONE_F + HATCHING +(CLONE_M*CLONE_F) + (CLONE_M*HATCHING) + (CLONE_F*HATCHING) + (CLONE_M*CLONE_F*HATCHING), family=quasipoisson) anova(model, test=Chi) I guess that those variables are factors, and that you have empty combinations? Make a coplot, and see whether you have data for all combinations of the levels of your factors. Formulated differently..does it make sense, or is it possible to fit the 3-way interaction for your data? Also..you may want to use the str command to see whether response is indeed coded correctly. Alain Error in if (dispersion == 1) Inf else object$df.residual : missing value where TRUE/FALSE needed If I fit the same model by using the Poisson distribution, it works. I have not a clue about where the problem could be. Do you have any idea or suggestion I could try? Thank you in advance, Ana __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. - Dr. Alain F. Zuur First author of: 1. Analysing Ecological Data (2007). Zuur, AF, Ieno, EN and Smith, GM. Springer. 680 p. 2. Mixed effects models and extensions in ecology with R. (2009). Zuur, AF, Ieno, EN, Walker, N, Saveliev, AA, and Smith, GM. Springer. 3. A Beginner's Guide to R (2009). Zuur, AF, Ieno, EN, Meesters, EHWG. Springer Statistical consultancy, courses, data analysis and software Highland Statistics Ltd. 6 Laverock road UK - AB41 6FN Newburgh Email: highs...@highstat.com URL: www.highstat.com -- View this message in context: http://www.nabble.com/GLM-quasipoisson-error-tp25754404p25770491.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] GLM quasipoisson error
Hello, I'm having an error when trying to fit the next GLM: model-glm(response ~ CLONE_M + CLONE_F + HATCHING +(CLONE_M*CLONE_F) + (CLONE_M*HATCHING) + (CLONE_F*HATCHING) + (CLONE_M*CLONE_F*HATCHING), family=quasipoisson) anova(model, test=Chi) Error in if (dispersion == 1) Inf else object$df.residual : missing value where TRUE/FALSE needed If I fit the same model by using the Poisson distribution, it works. I have not a clue about where the problem could be. Do you have any idea or suggestion I could try? Thank you in advance, Ana __ 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.
Re: [R] GLM quasipoisson error
atorso wrote: Hello, I'm having an error when trying to fit the next GLM: model-glm(response ~ CLONE_M + CLONE_F + HATCHING +(CLONE_M*CLONE_F) + (CLONE_M*HATCHING) + (CLONE_F*HATCHING) + (CLONE_M*CLONE_F*HATCHING), family=quasipoisson) anova(model, test=Chi) Error in if (dispersion == 1) Inf else object$df.residual : missing value where TRUE/FALSE needed If I fit the same model by using the Poisson distribution, it works. I have not a clue about where the problem could be. Do you have any idea or suggestion I could try? It would help if you gave a reproducible example. The following simple example seems to work. x = runif(100) y = rpois(100,x) mq = glm(y~x,family=quasipoisson) anova(mq,test=Chi) Other points: (1) I think you're a little bit confused about R model notation. * means main effects and all interactions, : means interaction only. You could rewrite your model more correctly as model-glm(response ~ CLONE_M + CLONE_F + HATCHING +(CLONE_M:CLONE_F) + (CLONE_M:HATCHING) + (CLONE_F:HATCHING) + (CLONE_M:CLONE_F:HATCHING), family=quasipoisson) or even better (compactly) as model-glm(response ~ CLONE_M*CLONE_F*HATCHING, family=quasipoisson) although all three ways give equivalent answers since the extra main-effect terms get dropped silently. (2) you should probably use test=F rather than test=Chisq for a quasi- model: see Crawley 2002 and/or Venables and Ripley. -- View this message in context: http://www.nabble.com/GLM-quasipoisson-error-tp25754404p25757025.html Sent from the R help mailing list archive at Nabble.com. __ 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.
