Creates exact posterior measure metadata used to distinguish a
continuous posterior from one containing atoms. Supply NULL to
explicitly declare that the posterior has no point masses.
posterior_atom_attribute(point_masses = NULL, source = "user")A posterior atom metadata object for the atoms metadata
of posterior draws (posterior_metadata(x, "atoms") <- ). Posterior
point masses are read only from these metadata: precomputed posterior
densities (posterior_density_attribute()) describe the continuous part
and carry no point masses.
BayesTools producers can additionally declare positional scalar
marginals, named in the full draw-column order. Scalar extraction
prefers these declarations; a continuous joint measure can have a point
marginal, for example the last level of an ordered point-total prior.
When a producer can certify only scalar marginals, the object records
joint_declared = FALSE and retains its typed joint refusal in
joint_unavailable. Its empty joint table is dimensional storage.
It does not declare an atom-free joint law. Scalar selection uses only
certified marginals; whole-law inference retains the joint refusal.