Thanks for that Gavin - yeah you're right that was not my actual model, which is:
GAMV2c<-gam(VASCSR~ROTATION+ CANCOV +LAreaoldwood+ + s(SOILPH) + CANCOV:LAreaoldwood + CANCOV:SOILPH,family=quasipoisson, data =HIGHBRYOSR) For MMI the script I use, and have used successfully with *exactly* same GAM with a poisson distribution, is: - ddGAMV2c<-dredge(GAMV2c) - ddGAMV2c The above 2 steps run fine - top.models4_GAMV2c<-get.models(ddGAMV2c, subset = delta <= 4, method="REML") So after request for "top.models" I get error * Error in update.formula(formula(object), formula.) : formula expected* And this is were I'm stumbling. I also tried - bestGAMV2c <- get.models(ddGAMV2c, cumsum(weight) <= .95) *Error in update.formula(formula(object), formula.) : formula expected* Again any help with this would be much appreciated as out of the 4 models I'm running through MMI for my data this is only one giving me problems (again all of the above script works fine with *exactly* same GAM model with a poisson distribution!) Regards, Karen On 4 February 2011 12:47, Gavin Simpson <gavin.simp...@ucl.ac.uk> wrote: > On Fri, 2011-02-04 at 12:31 +0000, Karen Moore wrote: > > Hi, > > > <snip /> > > My formula is > > > > GAM<-gam(Species richness (count) ~ Categorical + Continous + Continous > + * > > s*(Continous ) + Continous : Continous + Continous : Continous, > > family=quasipoisson, data =) > > Ok, I'm reasonably certain that that is *not* your gam() call. Why not > post the *actual* code you would enter for your GAM model? > > dd <- dredge(GAM) > > should evaluate all possible models from the global model you specified. > The example you quote is for a global model with both smooth and linear > terms for the same variables, hence in dredge() they need to select > models that include only the smooth for a particular variable or the > linear term for that variable, but not both. > > By the looks of it, you don't have this problem. > > G > > > > > Thanks for any advice on script > > > > > > Karen > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. Gavin Simpson [t] +44 (0)20 7679 0522 > ECRC, UCL Geography, [f] +44 (0)20 7679 0565 > Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk > Gower Street, London [w] > http://www.ucl.ac.uk/~ucfagls/<http://www.ucl.ac.uk/%7Eucfagls/> > UK. WC1E 6BT. [w] http://www.freshwaters.org.uk > %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% > > > -- Karen Moore PhD Researcher, FORESTBIO, Department of Botany, Trinity College Dublin Ireland Ph: 00 353 (0)87 9422 502 http://www.ucc.ie/en/planforbio [[alternative HTML version deleted]] ______________________________________________ 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.
