#1. model set-up
	model
	{
	  #likelihood p(Y|theta)
		for( i in 1 : N ) {
			for( j in 1 : T ) {
				Y[i , j] ~ dnorm(mu[i , j],tau.0)
				mu[i , j] <- a[i] + beta * trt[i] + b[i] * (x[j] - xbar)
			}
			#Prior p(theta|Psi)
			a[i] ~ dnorm(mu.a, tau.a)
			b[i] ~ dnorm(mu.b, tau.b)
		}
		#prior
		tau.0 ~ dgamma(0.001,0.001) 
		beta ~ dnorm(0.0,1.0E-6)
		
		#hyper-priors
		mu.a ~ dnorm(0.0,1.0E-6)	   
		mu.b ~ dnorm(0.0,1.0E-6)
		tau.a ~ dgamma(0.001,0.001)
		tau.b ~ dgamma(0.001,0.001)
		
		#parameters of interest
		sigma <- 1 / sqrt(tau.0) #error sd		
		w0[1] <- mu.a - xbar * mu.b	#weight at birth for 1st group
		w0[2] <- mu.a + beta - xbar * mu.b	#weight at birth for 2nd group
	}

#2. Data for BUGS use
list(x = c(8.0, 15.0, 22.0, 29.0, 36.0), xbar = 22, N = 30, T = 5, 
trt = c(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1),	
Y = structure(
			.Data =   c(151, 199, 246, 283, 320,
							 145, 199, 249, 293, 354,
							 147, 214, 263, 312, 328,
							 155, 200, 237, 272, 297,
							 135, 188, 230, 280, 323,
							 159, 210, 252, 298, 331,
							 141, 189, 231, 275, 305,
							 159, 201, 248, 297, 338,
							 177, 236, 285, 350, 376,
							 134, 182, 220, 260, 296,
							 160, 208, 261, 313, 352,
							 143, 188, 220, 273, 314,
							 154, 200, 244, 289, 325,
							 171, 221, 270, 326, 358,
							 163, 216, 242, 281, 312,
							 160, 207, 248, 288, 324,
							 142, 187, 234, 280, 316,
							 156, 203, 243, 283, 317,
							 157, 212, 259, 307, 336,
							 152, 203, 246, 286, 321,
							 154, 205, 253, 298, 334,
							 139, 190, 225, 267, 302,
							 146, 191, 229, 272, 302,
							 157, 211, 250, 285, 323,
							 132, 185, 237, 286, 331,
							 160, 207, 257, 303, 345,
							 169, 216, 261, 295, 333,
							 157, 205, 248, 289, 316,
							 137, 180, 219, 258, 291,
							 153, 200, 244, 286, 324),
						.Dim = c(30,5)))

#3. Initial values

###(3.1) only fixed effects
list(mu.a = 150, mu.b = 10,  beta=1, tau.0 = 1, tau.a = 1, tau.b = 1)

###(3.2) all parameters
list(a = c(250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 
	250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250, 250),
     b  = c(6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6),			
    mu.a = 150, mu.b = 10,  beta=1, tau.0 = 1, tau.a = 1, tau.b = 1)