Hi all, I did some analysis using package R2WinBUGS to call WinBUGS. I set the iterations to 50000 (fairly a large number, I think), but after the program was done, the effective posterior samples contained only 7 draws. I don't know why. By the way, I checked posterior sample size by using bugsobj$n.sims. And, for my previous practice with WinBUGS/R2WinBUGS, no such strange thing happend. Does anybody have some idea on what might be wrong with my model or whatever part in this program? Appreciate it. Anny [[alternative HTML version deleted]]
3 comments: 1. Quoting the last lines of this message: "PLEASE do read the posting guide R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code." Otherwise we cannot help anyway. 2. This is not the BUGS mailing list. 3. I do prefer BRugs, the R package that is based on OpenBUGS, because it is closer to BUGS, more flexible, sometimes easier to debug, .... Best wishes, Uwe Ligges Anny Huang wrote:> Hi all, > > I did some analysis using package R2WinBUGS to call WinBUGS. I set the > iterations to 50000 (fairly a large number, I think), but after the program > was done, the effective posterior samples contained only 7 draws. I don't > know why. > > By the way, I checked posterior sample size by using bugsobj$n.sims. And, > for my previous practice with WinBUGS/R2WinBUGS, no such strange thing > happend. Does anybody have some idea on what might be wrong with my model or > whatever part in this program? Appreciate it. > > Anny > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Uwe Ligges <ligges <at> statistik.tu-dortmund.de> writes:> 3. I do prefer BRugs, the R package that is based on OpenBUGS, because > it is closer to BUGS, more flexible, sometimes easier to debug, ....Which I strongly second, not only because of the author. Dieter
Anny Huang <annylhuang <at> gmail.com> writes:> I did some analysis using package R2WinBUGS to call WinBUGS. I set the > iterations to 50000 (fairly a large number, I think), but after the program > was done, the effective posterior samples contained only 7 draws. I don't > know why.This indicates that you have a mixing problem! I guess that you do not have enough information to retrieve the post. dist. of that parameter. You might try to reconsider your model or reparametrize it. gg