Struct StabilizationLedger 

pub struct StabilizationLedger {
    pub kind: StabilizationKind,
    pub delta: f64,
    pub matrix_form: RidgeMatrixForm,
    pub chosen_by: StabilizationRule,
    pub inertia_before: Option<Inertia>,
    pub inertia_after: Option<Inertia>,
}

Canonical record of a single stabilization δ applied at a single site.

Construct via the helper constructors (solver_damping, numerical_perturbation, explicit_prior) so the included_in_* invariants are guaranteed to match kind. Direct field construction is public for serialization round-trips only.

Fields

kind: StabilizationKind

delta: f64

matrix_form: RidgeMatrixForm

chosen_by: StabilizationRule

inertia_before: Option<Inertia>

inertia_after: Option<Inertia>

Implementations

impl StabilizationLedger

pub const fn none() -> Self

“No stabilization applied at this site” sentinel.

pub const fn solver_damping(delta: f64, chosen_by: StabilizationRule) -> Self

LM/TR damping. δ is invisible to the objective, gradient, and any saved artifact. Asserting this invariant at every read site is the whole reason the ledger exists.

pub const fn numerical_perturbation( delta: f64, chosen_by: StabilizationRule, backward_error_bound: Option<f64>, ) -> Self

Solver-only perturbation that leaves the objective unchanged. The caller may attach a backward-error bound when one is available (e.g. from iterative refinement / Wilkinson-style analysis).

pub const fn explicit_prior(delta: f64, matrix_form: RidgeMatrixForm) -> Self

Model-level explicit prior. δ enters every accounting pass: the quadratic penalty, the Laplace Hessian, the penalty log-determinant, and serialization.

pub const fn from_passport(passport: RidgePassport) -> Self

Bridge from the existing RidgePassport so PIRLS-side code (which already passes a RidgePassport through every call) can hand a ledger to anything that wants the new uniform view.

RidgePolicy is homogeneous-by-construction: every constructor sets the three inclusion flags identically. A passport whose policy excludes every accounting term is morally a numerical perturbation (the ridge is there to make the solve work but the objective ignores it); a passport whose policy includes every accounting term is an explicit prior. Heterogeneous flag combinations cannot be produced by the public RidgePolicy API and have no inhabitants downstream.

pub const fn quadratic_delta(&self) -> f64

δ value to fold into the quadratic penalty term, or 0.0 if this ledger entry is not part of the model. Derived from kind: only StabilizationKind::ExplicitPrior contributes.

pub const fn laplace_hessian_delta(&self) -> f64

δ value to add to the Laplace Hessian, or 0.0 if not included. Derived from kind: only StabilizationKind::ExplicitPrior contributes.

pub const fn penalty_logdet_delta(&self) -> f64

δ value to add inside log|S + δ I|, or 0.0 if not included. Derived from kind: only StabilizationKind::ExplicitPrior contributes.

Trait Implementations

impl Clone for StabilizationLedger

fn clone(&self) -> StabilizationLedger

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for StabilizationLedger

impl Debug for StabilizationLedger

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for StabilizationLedger

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for StabilizationLedger

fn eq(&self, other: &StabilizationLedger) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for StabilizationLedger

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for StabilizationLedger