Algorithm 1.
AIM procedure
| input: matrices Z, X, positive semi-definite matrix Q, λ2 > 0 |
| 1: define Q̃ := Q+λ2Ip; |
| 2: decompose Q̃ as Q̃ = L⊤L; |
| 3: find REML estimates σ̂2 and , of σ2 and , in LMM with X as matrix of fixed effects, ZL−1 as matrix of random effects, and ε ~ 𝒩(0,σ2In); |
| 4: define and find estimates β̂AIM and b̂AIM by applying formula (2.4) with matrix Q̃. |