Dear friends - AB[lev[j],1:2] ~ dmnorm(AB.hat[lev[j],],tau.AB[,]) I(lower[], upper[]) lower[1] <- 0 lower[2] <- 0 upper[1] <- 10 upper[2] <- 2 was suggested by Andrew Thomas and Dave Lunn, and it worked just fine to force the first entry to be positive and the last to be negative. I see now that in fact the "manual" suggested likewise, only I did not get its practical meaning. Thanks a lot Troels -- Troels Ring - - Department of nephrology - - Aalborg Hospital 9100 Aalborg, Denmark - - +45 99326629 - - [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