Relative entropy of one multivariate Gaussian from another, optionally split into its signal and dispersion parts.
Value
A named numeric vector with the total and, when decompose is
TRUE, the signal and dispersion parts.
Details
Public KL values never apply a covariance ridge; callers wanting
regularisation opt in explicitly with spd_floor(). andreou2026cir
(Section 2.2, closing paragraph) states that regularization is expected
only in the degenerate limit, which is the published basis for this
function's strictness. The state recursions are strict by default too, and
regularise only when a call asks for it with regularize = "floor"; see
aci_filter().