search for: dtweedi

...- tweedie.profile( y~1, p.vec=seq(1.1, 1.9, length=9), do.plot=TRUE) 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 .Error in .Fortran(.NAME = "pdfun", as.double(power), as.double(phi[i]/(y[i]^(2 - : supplied argument name '.NAME' does not match 'name' Calls: tweedie.profile -> dtweedie.inversion -> .Fortran Execution halted I've had a search--including a read of the "Writing R Extensions" manual on CRAN (I did read it, but interestingly a search of that document did not reveal any instance of .NAME)--and I cannot see the problem. It's probably obvious....

Dear Catarina, I prefer to leave the AIC value as NA for the tweedie GLM family because it takes extra time to compute and is only occasionally wanted. It's easy to compute the AIC yourself using the dtweedie() function of the tweedie package. Best wishes Gordon At 03:05 AM 14/08/2007, Catarina Miranda wrote: >Dear Gordon; > >I have also sent this email to R help mailing list, so I apologize >for duplicated mailing. >I am modelling densities of some species of birds, and I have a &g...

...-1.6     dat$resp<-rtweedie(nrow(dat),p,mu,phi)   y<-dat$resp th<-c(rep(0,ncol(x)),1,1,1.5) beta<-th[1:ncol(x)] sig<-th[ncol(x)+1] phi<-th[ncol(x)+2] p<-th[ncol(x)+3] z.ast<-sig*z l.u<-function(u,y,z,x,beta,phi,p){   eta.u<-as.vector(x%*%beta+z%*%u)   f.y<-log(dtweedie(y,p,exp(eta.u),phi))   l.yu<-sum(f.y)+sum(dnorm(u,log=T))   return(-l.yu) } uhat<-optim(rep(0,ncol(z)),l.u,method="BFGS",hessian=T,             y=y,z=z.ast,x=x,beta=beta,phi=phi,p=p) [[alternative HTML version deleted]]

...earch turned up AICtweedie, within the tweedie package, but I get the following message: Error: could not find function "AICtweedie" when I try to use this command, even though "tweedie" and "statmod" are both loaded. I've also read that AIC can be calculated using dtweedie, but I'm a beginner and so, despite lots of searching, I'm not sure how. I'm sorry to ask a basic statistics rather than programming question, but I'm really stuck. Could anyone advise me on the best way to assess goodness-of-fit for this type of model, in order to compare models?...