Skip to main content
. Author manuscript; available in PMC: 2010 Nov 30.
Published in final edited form as: Comput Stat Data Anal. 2008 Aug 15;52(12):5100–5120. doi: 10.1016/j.csda.2008.05.008
For each sampled set of knots, (k, tk, k′, tk), do the following:
  1. For t = 1 : L (we set L = 100)

    1. Sample the modified Cholesky parameters ψ and log (σ2) from
      (ψtlog(σ2,t))~MVN((ψ^log(σ^2)),I(ψ^,log(σ^2))1),
      where (ψ̂, σ̂2) are the maximum likelihood estimates of the Pourhamadi parameters and σ2 corresponding to the current set of knots, and I (ψ̂, log (σ̂2)) is their information matrix evaluated at these estimates.
    2. Accept this draw with probability
      min(1,p(y|k,tk,k,tk,ψt,σ2,t)p(ψt|k,tk)p(σ2,t)ξ(ψt,log(σ2,t))p(y|k,tk,k,tk,ψt1,σ2,t1)p(ψt1|k,tk)p(σ2,t1)ξ(ψt1,log(σ2,t1)))
      where pt|k′, tk) is the prior distribution of ψ evaluated at ψt, p2,t) is the prior distribution of σ2 evaluated at σ2,t, and ξ (ψt, log (σ2,t)) is the multivariate normal density given in step (a) evaluated at (ψt, log (σ2,t)).
    3. If the move is not accepted, let ψt = ψt–1, log(σ2,t) = log(σ2,t–1)

  2. Draw a fixed effect, α*, from the conditional posterior distribution α|k,tk,k,tk,Σγt,σ2,t where α|k,tk,k,tk,Σγt,σ2,t~MVN((FC1F)1FC1(Y,α^),(FC1F)1),F=(BF1,BF2,,BFn,Ik+2), C is a block-diagonal matrix composed of the n matrices {(BRiΣγtBRi+σ2,tImi)}i=1n and the matrix – (1ni=1n1miIα,i(α^))1, BFi, and BRi are defined in Section 3, Y is all of the observed data, and α̂ is the maximum likelihood estimate of α.

  3. Draw a random effect, γ*, from the conditional posterior distribution γ|k,tk,k,tk,α*,Σγt,σ2,t where γ|k,tk,k,tk,α*,Σγt,σ2,t~MVN(λ,Λ),λ=ΣγtBRi(σ2,tImi)1(YiBFiα*), and
    Λ=γtBRi{(σ2,tImi)1(σ2,tImi)1BFi(1σ2,ti=1nBFiBFi)1BFi(σ2,tImi)1}BRiγt