Enum FittedInverse 

pub enum FittedInverse<'a> {
    FaerCholesky(&'a FaerCholeskyFactor),
    LowerTriangular(&'a Array2<f64>),
    Projected {
        basis: &'a Array2<f64>,
        reduced_inverse: &'a Array2<f64>,
    },
}

The fitted curvature in whichever factored form the solver produced — the SINGLE place that knows how to invert it.

Variants

FaerCholesky(&'a FaerCholeskyFactor)

Cholesky factor of the (stabilized) penalized Hessian: the full-rank convention (PIRLS / ALO path).

LowerTriangular(&'a Array2<f64>)

Raw lower-triangular Cholesky factor L with H = L·Lᵀ (the arrow-Schur reduced factor in evidence.rs).

Projected

Projected (pseudo-)inverse U · M⁻¹ · Uᵀ over a column basis U (p × r) with reduced inverse M⁻¹ (r × r) — the rank-deficient LAML convention (#752/0dc469bd/#901): the inverse acts on range(U) and annihilates its complement.

Fields

basis: &'a Array2<f64>

reduced_inverse: &'a Array2<f64>