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Build a prior list for tulpa_nested_laplace() from a tulpa spec object

Source: R/nested_laplace.R
prior_from_spec.Rd

Validates a tulpa_temporal or tulpa_spatial specification against data, then converts it to the prior list shape consumed by tulpa_nested_laplace(). Mainly an internal helper for callers that already have a fitted spec; users typically pass spec + data directly to tulpa_nested_laplace() instead.

Supported spec types:

  • tulpa_temporal with type in {"rw1", "rw2", "ar1"}

  • tulpa_spatial, areal type in {"car", "icar", "car_proper", "bym2"}. An areal spec returns the graph fields only – type, spatial_idx, n_spatial_units, adj_row_ptr, adj_col_idx, n_neighbors – plus scale_factor for bym2 and the eigenvalue-derived rho_bounds for proper CAR. No grid field is returned for any areal type: the outer axes are built later by the family's registry defaults() closure, and proper CAR's (tau, rho) grid is built there from those bounds.

  • tulpa_gp / tulpa_hsgp, continuous type in {"gp", "nngp", "hsgp"}: validated against data and routed to the nngp / hsgp nested kernel through the shared converter.

SPDE is the one continuous field not built here – it carries its own (range, sigma) FEM integrator; call fit_spde() with the spatial_spde() spec.

Usage

prior_from_spec(spec, data)

Arguments

spec

A tulpa_temporal or tulpa_spatial object.

data

Data frame the spec resolves time/group/site indices against.

Value

A prior list ready for tulpa_nested_laplace().