model
   {
      for (i in 1 : N) {
         for (j in 1 : M) {
   # Survival times bounded below by censoring times:
            t[i,j] ~ dweib(r, mu[i,j]) I(t.cen[i, j], );
            log(mu[i,j ]) <- alpha + beta.age * age[i, j] 
                  + beta.sex *sex[i] 
                  + beta.dis[disease[i]] + b[i];
         }
   # Random effects:
         b[i] ~ dnorm(0.0, tau) 
      }
   # Priors:
      alpha ~ dnorm(0.0, 0.0001);
      beta.age ~ dnorm(0.0, 0.0001);
      beta.sex ~ dnorm(0.0, 0.0001);
   #   beta.dis[1] <- 0; # corner-point constraint
      for(k in 2 : 4) {
         beta.dis[k] ~ dnorm(0.0, 0.0001);
      }
      tau ~ dgamma(1.0E-3, 1.0E-3);
      r ~ dgamma(1.0, 1.0E-3); 
      sigma <- 1 / sqrt(tau); # s.d. of random effects
   }