tandx

BytheMarkovian assumption forlatent state vectors, the Hessian matrix is tri-block diagonal. To facilitate convergence, we initialize the Newton update with a smoothing estimate bylocalGaussian approximation. Theforwardfiltering foradynamic Poisson modelhas been previously described (Eden etal., 2004), and we use anadditional backward pass tosmooth (Rauchetal.,1965). Without constraints, the sampling ofh(j), g(j) and σ2(j) is the same as shown previously. The update of A(j), b(j) and Q(j) is the standard multivariate Bayesian linear regression.