IncompleteCholesky.hpp

/*
 * Copyright 2025 INRIA
 */

#ifndef __eigenpy_solvers_incomplete_cholesky_hpp__
#define __eigenpy_solvers_incomplete_cholesky_hpp__

#include "eigenpy/eigenpy.hpp"
#include "eigenpy/utils/scalar-name.hpp"

namespace eigenpy {

template <typename _MatrixType>
struct IncompleteCholeskyVisitor : public boost::python::def_visitor<
 IncompleteCholeskyVisitor<_MatrixType>> {
 typedef _MatrixType MatrixType;
 typedef typename MatrixType::Scalar Scalar;
 typedef typename MatrixType::RealScalar RealScalar;
 typedef Eigen::IncompleteCholesky<Scalar> Solver;
 typedef Eigen::Matrix<Scalar, Eigen::Dynamic, 1, MatrixType::Options>
 DenseVectorXs;
 typedef Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic,
 MatrixType::Options>
 DenseMatrixXs;

 typedef Eigen::SparseMatrix<Scalar, Eigen::ColMajor> FactorType;
 typedef Eigen::Matrix<RealScalar, Eigen::Dynamic, 1> VectorRx;
 typedef Eigen::PermutationMatrix<Eigen::Dynamic, Eigen::Dynamic>
 PermutationType;

 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("rows", &Solver::rows, bp::arg("self"),
 "Returns the number of rows of the matrix.")
 .def("cols", &Solver::cols, bp::arg("self"),
 "Returns the number of cols of the matrix.")

 .def("info", &Solver::info, bp::arg("self"),
 "Reports whether previous computation was successful.")

 .def("setInitialShift", &Solver::setInitialShift,
 bp::args("self", "shift"), "Set the initial shift parameter.")

 .def(
 "analyzePattern",
 +[](Solver& self, const MatrixType& amat) {
 self.analyzePattern(amat);
 },
 bp::arg("matrix"))
 .def(
 "factorize",
 +[](Solver& self, const MatrixType& amat) { self.factorize(amat); },
 bp::arg("matrix"))
 .def(
 "compute",
 +[](Solver& self, const MatrixType& amat) { self.compute(amat); },
 bp::arg("matrix"))

 .def(
 "matrixL",
 +[](const Solver& self) -> const FactorType& {
 return self.matrixL();
 },
 bp::return_value_policy<bp::copy_const_reference>())
 .def(
 "scalingS",
 +[](const Solver& self) -> const VectorRx& {
 return self.scalingS();
 },
 bp::return_value_policy<bp::copy_const_reference>())
 .def(
 "permutationP",
 +[](const Solver& self) -> const PermutationType& {
 return self.permutationP();
 },
 bp::return_value_policy<bp::copy_const_reference>())

 .def(
 "solve",
 +[](const Solver& self, const Eigen::Ref<DenseVectorXs const>& b)
 -> DenseVectorXs { return self.solve(b); },
 bp::arg("b"),
 "Returns the solution x of A x = b using the current decomposition "
 "of A, where b is a right hand side vector.")
 .def(
 "solve",
 +[](const Solver& self, const Eigen::Ref<DenseMatrixXs const>& B)
 -> DenseMatrixXs { return self.solve(B); },
 bp::arg("b"),
 "Returns the solution X of A X = B using the current decomposition "
 "of A where B is a right hand side matrix.")
 .def(
 "solve",
 +[](const Solver& self, const MatrixType& B) -> MatrixType {
 DenseMatrixXs B_dense = DenseMatrixXs(B);
 DenseMatrixXs X_dense = self.solve(B_dense);
 return MatrixType(X_dense.sparseView());
 },
 bp::arg("b"),
 "Returns the solution X of A X = B using the current decomposition "
 "of A where B is a right hand side matrix.");
 }

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

 static void expose(const std::string& name) {
 bp::class_<Solver, boost::noncopyable>(name.c_str(), "Incomplete Cholesky.",
 bp::no_init)
 .def(IncompleteCholeskyVisitor())
 .def(IdVisitor<Solver>());
 }
};

} // namespace eigenpy

#endif // ifndef __eigenpy_solvers_incomplete_cholesky_hpp__