Structural dependence overview
Status — Stable
Mirrors drmTMB's Structural dependence overview. In DRM.jl today: all four structured-effect markers on the mean — relmat (supplied K), animal (pedigree A), phylo (tree), and spatial (coordinates) — are available. For Gaussian responses with these effects on the mean, latent effects integrate out exactly; covariance parameters are estimated numerically. The q=4 phylogenetic bivariate engine is also available.
A structured effect puts a known correlation among the group-level random intercepts instead of treating groups as independent. The marker names where that correlation comes from:
| Marker | Correlation source | Supply |
|---|---|---|
relmat(1 | id) | an arbitrary known matrix K | K = … |
animal(1 | id) | an additive-genetic pedigree | A = … |
phylo(1 | species) | a phylogenetic tree | tree = … |
spatial(1 | site) | distance between coordinates | coords = … (range estimated) |
For Gaussian responses with Gaussian structured effects entering the mean linearly and residual variance independent of those effects, all four have the exact marginal covariance V = D + σ_s² Z K Zᵀ. No Laplace approximation is needed in this case. Covariance parameters are still estimated numerically. Each has its own worked tutorial — see below.