Module kkt 

Interior point operator assembly for the DC-OPF Newton step.

The Θ⁻¹ diagonals are central-path state (they change every IPM iteration), so they are passed in, never derived from the case. Given the case factors A, b, L and the bus cost q, this builds the operators the reduced Newton system needs:

L_eff = A B Θf⁻¹ B Aᵀ + L Dg⁻¹ L = L₁ + L₂ D L₂,   Dg = (Q + Θg⁻¹)⁻¹

The solver multiplies by L₁, solves with L₂ = L, and scales by D^{±1/2}, all grounded at the slack bus, so the grounded factors are the primary output; the dense L_eff is optional.

Structs

KktOperators

The grounded operators a step of the EKS solver consumes, plus their ungrounded forms and the diagonal D = Dg⁻¹.

Functions

assemble_kkt

Assemble the reduced KKT operators from the case factors and the caller-supplied positive interior point diagonals.

assemble_reduced_kkt

Assemble the full reduced augmented KKT block (eq. “reduced”): a symmetric indefinite saddle matrix in (Δp_g, Δθ, Δf, Δν, Δη, Δρ) of size 3n + 2m + 1. Useful as a single operator for a direct factorization.