Use alias() to help here. It is likely that one of S T L only occurs (or does not occur) at level 6 of C.
On Wed, 19 Apr 2006, [EMAIL PROTECTED] wrote: > Hello, > > i have the following model, > > poi1<-glm(F~S+T+L+C,family=poisson,x=T) > > where F,S,T,L are metric and C is a factor variable with the levels "0", > "1", "2", "3", "4", "5" and "6" > > if i do summary(poi1), i get the following > > Call: > glm(formula = F ~ S + T + L + C, family = poisson, x = T) > > Deviance Residuals: > > Min 1Q Median 3Q Max > > -2.44054 -0.80997 -0.04627 0.69402 2.90301 > > Coefficients: (1 not defined because of singularities) > Estimate Std. Error z value Pr(>|z|) > > (Intercept) -10.45553 1.16221 -8.996 < 2e-16 *** > > S 1.08024 0.13609 7.938 2.06e-15 *** > > T 1.63582 0.05170 31.643 < 2e-16 *** > > L 3.31684 0.49965 6.638 3.17e-11 *** > > C1 0.21256 0.16449 1.292 0.1963 > > C2 -0.10895 0.06675 -1.632 0.1027 > > C3 0.15159 0.06992 2.168 0.0302 * > > C4 0.50949 0.05870 8.680 < 2e-16 *** > > C5 0.11240 0.01686 6.667 2.61e-11 *** > > C6 NA NA NA NA > > --- > > Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 > > (Dispersion parameter for poisson family taken to be 1) > > Null deviance: 47365.29 on 495 degrees of freedom > > Residual deviance: 574.64 on 487 degrees of freedom > > AIC: 4091.8 > > Number of Fisher Scoring iterations: 4 > > > my question now is why do i get those "singularities" and where do they > come from, i guess because of the singularites i get the NA's, what can > i do here to avoid them? > I think i have done some wrong dummy coding or something like that? By > the way, i have 7 levels and only got estimates for 6 levels, whats > wrong here? > > best regards > andreas > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
