Dear r-helpers, I can run the examples on the mcsamp help page. For example: **************************************** > M1 <- lmer (y1 ~ x + (1|group)) > (M1.sim <- mcsamp (M1)) fit using lmer, 3 chains, each with 1000 iterations (first 500 discarded) n.sims = 1500 iterations saved mean sd 2.5% 25% 50% 75% 97.5% Rhat n.eff beta.(Intercept) 0.1 0.7 -1.2 -0.3 0.1 0.5 1.4 1.0 1500 beta.x 2.5 0.4 1.7 2.2 2.5 2.7 3.2 1.0 1500 sigma.y 3.8 0.3 3.3 3.6 3.7 3.9 4.3 1.0 61 sigma.grop.(In) 1.5 0.8 0.0 1.0 1.4 1.9 3.3 1.4 12 eta.group.(Intercept)[1] 0.0 1.0 -2.1 -0.5 0.0 0.6 2.0 1.0 1500 eta.group.(Intercept)[2] 1.0 1.1 -0.9 0.2 0.9 1.7 3.4 1.0 59 eta.group.(Intercept)[3] -1.3 1.2 -4.0 -2.0 -1.3 -0.4 0.5 1.0 66 eta.group.(Intercept)[4] 1.3 1.1 -0.6 0.4 1.1 2.0 3.7 1.1 43 eta.group.(Intercept)[5] -0.7 1.0 -3.0 -1.4 -0.6 0.0 1.2 1.0 120 eta.group.(Intercept)[6] 1.5 1.2 -0.3 0.6 1.4 2.2 4.0 1.0 49 eta.group.(Intercept)[7] 0.3 1.0 -1.7 -0.3 0.1 0.8 2.5 1.0 440 eta.group.(Intercept)[8] -1.6 1.2 -4.0 -2.4 -1.5 -0.6 0.3 1.1 41 eta.group.(Intercept)[9] 0.4 1.0 -1.6 -0.2 0.2 0.9 2.7 1.0 180 eta.group.(Intercept)[10] -1.0 1.1 -3.3 -1.6 -0.9 -0.2 0.8 1.0 86
For each parameter, n.eff is a crude measure of effective sample size, and Rhat is the potential scale reduction factor (at convergence, Rhat=1). **************************************** But when I try to do this with my own data I get an error: **************************************** > display(e7.lmer2) lmer(formula = baLO ~ I(baRatio - 0.985) + delta + (1 + I(baRatio - 0.985) + delta | subject), data = e7) coef.est coef.se (Intercept) -0.19 0.06 I(baRatio - 0.985) -4.95 0.74 delta 0.41 0.06 Error terms: Groups Name Std.Dev. Corr subject (Intercept) 0.13 I(baRatio - 0.985) 2.57 0.45 delta 0.22 -0.12 -0.94 Residual 0.39 number of obs: 494, groups: subject, 13 deviance = 551.4 > e7.sim <- mcsamp(e7.lmer2) Error in as.bugs.array(sims, program = "lmer", n.iter = n.iter, n.burnin = n.burnin, : error in parameter sigma. in parameters.to.save **************************************** I would appreciate a pointer to what the problem might be. _____________________________ Professor Michael Kubovy University of Virginia Department of Psychology USPS: P.O.Box 400400 Charlottesville, VA 22904-4400 Parcels: Room 102 Gilmer Hall McCormick Road Charlottesville, VA 22903 Office: B011 +1-434-982-4729 Lab: B019 +1-434-982-4751 Fax: +1-434-982-4766 WWW: http://www.people.virginia.edu/~mk9y/ ______________________________________________ R-help@stat.math.ethz.ch mailing list 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.