SimplicialLDLT.hpp

/*
 * Copyright 2024 INRIA
 */

#ifndef __eigenpy_decompositions_sparse_simplicial_ldlt_hpp__
#define __eigenpy_decompositions_sparse_simplicial_ldlt_hpp__

#include "eigenpy/eigenpy.hpp"
#include "eigenpy/decompositions/sparse/SimplicialCholesky.hpp"
#include "eigenpy/utils/scalar-name.hpp"

namespace eigenpy {

template <typename _MatrixType, int _UpLo = Eigen::Lower,
 typename _Ordering =
 Eigen::AMDOrdering<typename _MatrixType::StorageIndex>>
struct SimplicialLDLTVisitor
 : public boost::python::def_visitor<
 SimplicialLDLTVisitor<_MatrixType, _UpLo, _Ordering>> {
 typedef SimplicialLDLTVisitor<_MatrixType, _UpLo, _Ordering> Visitor;
 typedef _MatrixType MatrixType;

 typedef Eigen::SimplicialLDLT<MatrixType> Solver;
 typedef typename MatrixType::Scalar Scalar;
 typedef typename MatrixType::RealScalar RealScalar;
 typedef Eigen::Matrix<Scalar, Eigen::Dynamic, 1, MatrixType::Options>
 DenseVectorXs;
 typedef Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic,
 MatrixType::Options>
 DenseMatrixXs;

 template <class PyClass>
 void visit(PyClass &cl) const {
 cl.def(bp::init<>(bp::arg("self"), "Default constructor"))
 .def(bp::init<MatrixType>(bp::args("self", "matrix"),
 "Constructs and performs the LDLT "
 "factorization from a given matrix."))

 .def("vectorD", &vectorD, bp::arg("self"),
 "Returns the diagonal vector D.")
 .def(SimplicialCholeskyVisitor<Solver>());
 }

 static void expose() {
 static const std::string classname =
 "SimplicialLDLT_" + scalar_name<Scalar>::shortname();
 expose(classname);
 }

 static void expose(const std::string &name) {
 bp::class_<Solver, boost::noncopyable>(
 name.c_str(),
 "A direct sparse LDLT Cholesky factorizations.\n\n"
 "This class provides a LDL^T Cholesky factorizations of sparse "
 "matrices that are selfadjoint and positive definite."
 "The factorization allows for solving A.X = B where X and B can be "
 "either dense or sparse.\n\n"
 "In order to reduce the fill-in, a symmetric permutation P is applied "
 "prior to the factorization such that the factorized matrix is P A "
 "P^-1.",
 bp::no_init)
 .def(SimplicialLDLTVisitor())
 .def(IdVisitor<Solver>());
 }

 private:
 static DenseVectorXs vectorD(const Solver &self) { return self.vectorD(); }
};

} // namespace eigenpy

#endif // ifndef __eigenpy_decompositions_sparse_simplicial_ldlt_hpp__