coefficient_curvature

property SuperLSS.coefficient_curvature: str

Return the curvature the dense coefficient solve is asked to use.

"observed" (the default) is Newton’s method on the observed Hessian for every family; "fisher" requests Fisher scoring and needs a family with expected information. Under either policy a materially indefinite terminal penalized observed Hessian falls back to penalized expected information when the family supplies it, and is refused otherwise.