I am trying to run a simple one-dimensional Bayesian IRT-model on a 9 (respondents)*43(items) dataset, but I want to specify separate normal priors for my item-parameters.
With sample data, I run data(SupremeCourt) priors<-matrix(NA,ncol=43,nrow=2) priors[1,]<-0 priors[2,]<-seq(1,43,1) posterior3 <- MCMCirtKd(t(SupremeCourt),dimensions=1, theta.constraints=list(Scalia="+", Ginsburg="-"), b0=priors, B0=1000, burnin=5, mcmc=2000, thin=5, verbose=500, store.item=TRUE,store.ability=F) I assume from the documentary that b0 "Can be either a scalar or a matrix of dimension (K + 1) × items". But if I run this, no matter how I specify it, I get "l0 neither matrix, list, nor scalar". It seems like a package-bug to me, but I have no clue how to specify separate priors for item-parameters. Thanks, Tobi [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.