###################### # Dugongs Nonlinear model # See Carlin and Louis (2008), Example 4.3 ###################### model { for( i in 1 : N ) { Y[i] ~ dnorm(mu[i], tau) mu[i] <- alpha - beta * pow(gamma,x[i]) } alpha ~ dflat() beta ~ dflat() gamma ~ dunif(0.5, 1.0) U3 <- logit(gamma) tau <- 1/(sigma*sigma) sigma ~ dunif(0.01, 100) } #Data: list(x = c( 1.0, 1.5, 1.5, 1.5, 2.5, 4.0, 5.0, 5.0, 7.0, 8.0, 8.5, 9.0, 9.5, 9.5, 10.0, 12.0, 12.0, 13.0, 13.0, 14.5, 15.5, 15.5, 16.5, 17.0, 22.5, 29.0, 31.5), Y = c(1.80, 1.85, 1.87, 1.77, 2.02, 2.27, 2.15, 2.26, 2.47, 2.19, 2.26, 2.40, 2.39, 2.41, 2.50, 2.32, 2.32, 2.43, 2.47, 2.56, 2.65, 2.47, 2.64, 2.56, 2.70, 2.72, 2.57), N = 27) # Inits: list(alpha = 1, beta = 1, sigma = 1, gamma = 0.9) list(alpha = 10, beta = 10, sigma = 10, gamma = 0.7) list(alpha = 100, beta = 100, sigma = 100, gamma = 0.5) # Results: node mean sd MC error 2.5% median 97.5% start sample U3 1.859 0.2723 0.005911 1.305 1.863 2.39 5001 48000 alpha 2.652 0.07341 0.001559 2.529 2.646 2.815 5001 48000 beta 0.9741 0.07769 5.816E-4 0.826 0.973 1.131 5001 48000 gamma 0.8621 0.03298 6.931E-4 0.7867 0.8657 0.916 5001 48000 sigma 0.09914 0.01514 1.01E-4 0.07468 0.09736 0.1338 5001 48000 tau 108.6 31.67 0.1976 55.86 105.5 179.3 5001 48000