Hi Simon, Thank you so much for being active on this list, it really is tremendously helpful.
Thanks you for your insights, I was wondering whether both terms were necessary. As for 'NB wouldn't work' it was a convergence problem (and tremendously slow). There were also issues with the models not giving lack of convergence warnings but then the model saying it was not converged and vice versa. The QP seemed to fit the data well (and quickly) so we switched to that. Thanks again. Trevor On Wed, Jul 16, 2014 at 12:44 PM, Simon Wood <s.w...@bath.ac.uk> wrote: > Trevor, > > It looks like you've added a parametric COR.YEARLY.MEAN in addition to > your s(cxe,cyn,by=COR.YEARLY.MEAN) term. Because the latter includes a > linear effect of COR.YEARLY.MEAN, then the parametric COR.YEARLY.MEAN will > not be identifiable, so gam has dropped it. > > I guess from the scale parameter your data are, if anything, > under-dispersed relative to Poisson, but perhaps Poisson would have been ok > too. > > Could you give a bit more detail on 'NB just wouldn't work' please? What > actually happened? (It's new functionality, so having reports when stuff > goes wrong is useful). > > best, > Simon > > > On 16/07/14 20:25, Trevor Davies wrote: > >> I have run a quasipoisson spatial model via GAM (NB just wouldn't work) >> and >> I am getting the following output of one of my parameters >> (COR.YEARLY.MEAN). Does this suggest an error in the model fit? The model >> seems to have converged. Apologies for the lack of reproducible example >> but it didn't really seem warranted in this case. Thank you for the >> assistance. >> Trevor >> >> Parametric coefficients: >> Estimate Std. Error t value Pr(>|t|) >> (Intercept) -3.7084 0.2185 -16.97 <2e-16 *** >> COR.YEARLY.MEAN 0.0000 0.0000 NA NA >> --- >> >> Approximate significance of smooth terms: >> edf Ref.df F p-value >> s(PRED_cBOTTOM_TEMPERATURE.std) 5.008 6.045 24.871 < 2e-16 >> *** >> s(cxe,cyn) 28.999 29.000 13.951 < 2e-16 *** >> s(cDMAX.std) 3.830 4.761 243.895 < 2e-16 *** >> s(cxe,cyn):male.allyear.intensity.std 8.053 9.923 4.486 2.8e-06 >> *** >> s(cxe,cyn):female.allyear.intensity.std 3.733 4.334 5.478 0.000149 >> *** >> s(cxe,cyn):COR.YEARLY.MEAN 28.979 29.886 28.502 < 2e-16 *** >> s(cxe,cyn):cFISHING_INTENSITY.std 5.592 6.464 24.330 < 2e-16 >> *** >> - >> Rank: 1/169 >> R-sq.(adj) = 0.697 Deviance explained = 64.1% >> GCV = 0.70372 Scale est. = 0.69061 n = 4575 >> >> [[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. >> >> > > -- > Simon Wood, Mathematical Science, University of Bath BA2 7AY UK > +44 (0)1225 386603 http://people.bath.ac.uk/sw283 > [[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.
