pounce-linalg

Linear algebra primitives for POUNCE. Port of Ipopt's src/LinAlg/.

Internal crate. Like upstream, POUNCE uses an object-oriented vector / matrix layer over concrete dense and structured types, so the algorithm-side code can talk to compound iterates without knowing the underlying storage.

What's in it

• Traits — Vector, Matrix, SymMatrix: the abstract surface every concrete type implements (IpVector.hpp, IpMatrix.hpp, IpSymMatrix.hpp).
• Dense — DenseVector, DenseGenMatrix, DenseSymMatrix with companion *Space factories.
• Compound — CompoundVector, CompoundMatrix, CompoundSymMatrix: block-structured iterates, used heavily by the IPM (x, s, λ, ν, z_L, z_U live in a single CompoundVector).
• Structured — DiagMatrix, ExpansionMatrix, IdentityMatrix, ZeroMatrix, SumMatrix, ScaledMatrix, TransposeMatrix, LowRankUpdateSymMatrix, MultiVectorMatrix.
• Sparse triplets — GenTMatrix, SymTMatrix (COO storage), TripletToCsrConverter for handing matrices to sparse linear solvers.
• BLAS-1 — blas1 module with hand-rolled inner loops; no system BLAS dependency.

Why an OO layer?

The IPM never instantiates a raw 𝐱 ∈ ℝⁿ — it operates on a compound iterate with substructure that downstream operators (e.g. the augmented KKT system, line-search expansion, scaling) need to know about. The Vector / Matrix traits, with VectorCache / MatrixCache keyed on the upstream Tag machinery (see pounce-common), let strategies operate on iterates without touching storage details.

License

EPL-2.0.