pounce-linsol 0.5.0

Symmetric linear-solver trait layer for POUNCE (port of Ipopt's Algorithm/LinearSolvers/Ip{SymLinearSolver,SparseSymLinearSolverInterface,TSymLinearSolver,TSymScalingMethod,TripletToCSRConverter}). No FFI; concrete backends live in pounce-hsl, pounce-mumps (future), pounce-feral (future).
Documentation

pounce-linsol

Symmetric linear-solver trait layer for POUNCE. Port of Ipopt's Algorithm/LinearSolvers/. Defines the contracts that concrete backends (FERAL, MA57, future MUMPS) implement; contains no FFI of its own.

The two-level trait stack

Trait Operates on Mirrors
SymLinearSolver SymMatrix (compound) IpSymLinearSolver.hpp
SparseSymLinearSolverInterface triplet/CSC slices IpSparseSymLinearSolverInterface.hpp

The wrapper TSymLinearSolver (port of IpTSymLinearSolver.{hpp,cpp}) adapts the second to the first, handling the triplet-to-CSR conversion and scaling pipeline so backends only have to implement the low-level trait.

Return states live in ESymSolverStatus (Success, Singular, WrongInertia, CallAgain, FatalError). The CallAgain / pivtol_changed protocol is preserved verbatim from MA57 because the IPM's PdFullSpaceSolver depends on it.

Where backends live

  • pounce-feral — pure-Rust FERAL backend (default). No external dependencies.
  • pounce-hsl — MA57 via libcoinhsl (optional, behind the ma57 feature on pounce-cli / pounce-algorithm).
  • MUMPS — slotted for v1.1.

Scaling

TSymScalingMethod is the scaling-strategy trait (port of IpTSymScalingMethod.hpp). Three implementations ship:

  • IdentityScalingMethod — null scaling, the default.
  • RuizTSymScalingMethod (this crate) — symmetric Ruiz ∞-norm equilibration. Pure Rust. Selected by linear_system_scaling = ruiz.
  • Mc19TSymScalingMethod (in pounce-hsl) — HSL MC19 (Curtis-Reid) via libcoinhsl. Selected by linear_system_scaling = mc19.

License

EPL-2.0.