Print

Print


Dear all,

not long ago I started working with WinBUGS and  within that espeacially 
the car.proper model. I have a linear mixed model with random effects u 
which are correlated and jointly normal distributed. So far I just 
copy-pasted examples which looked like

u[1:k]~car.proper(mu[] ,C[] , adj[] ,num[] ,m[] , tau ,gamma)
gamma.min <- min.bound(C[], adj[], num[], m[])
gamma.max <- max.bound(C[], adj[], num[], m[])
gamma ~ dunif(gamma.min, gamma.max)

Like I understood the gamma represents the degree of spatial dependence. 
I would like to estimate it. As a start I just took a mean of the 
monitored gammas (I'm only monitoring the u's and gamma). This gave me 
no good estimation. Since I am not that deep into the program my idea 
was simply that this problem might be due to the uniform distribution. 
Maybe a truncated normal with the latter gamma as mean might be a better 
idea? I am thankful for any recommendation.

Best wishes
Beate Weidenhammer

-- 
Beate Weidenhammer
wiss. Mitarbeiterin
Freie Universität Berlin
Fachbereich Wirtschaftswissenschaft
Institut für Statistik und Ökonometrie
Lehrstuhl Rendtel
Garystr. 21 (Raum 325)
D-14195 Berlin
Tel.: +49 30 838-54203
Fax: +49 30 838-456629
email: [log in to unmask]

-------------------------------------------------------------------
This list is for discussion of modelling issues and the BUGS software.
For help with crashes and error messages, first mail [log in to unmask]
To mail the BUGS list, mail to [log in to unmask]
Before mailing, please check the archive at www.jiscmail.ac.uk/lists/bugs.html
Please do not mail attachments to the list.
To leave the BUGS list, send LEAVE BUGS to [log in to unmask]
If this fails, mail [log in to unmask], NOT the whole list