RealSchur.hpp

/*
 * Copyright 2025 INRIA
 */

#ifndef __eigenpy_decompositions_generalized_real_schur_hpp__
#define __eigenpy_decompositions_generalized_real_schur_hpp__

#include <Eigen/Core>
#include <Eigen/Eigenvalues>

#include "eigenpy/eigen-to-python.hpp"
#include "eigenpy/eigenpy.hpp"
#include "eigenpy/utils/scalar-name.hpp"

namespace eigenpy {

template <typename _MatrixType>
struct RealSchurVisitor
 : public boost::python::def_visitor<RealSchurVisitor<_MatrixType>> {
 typedef _MatrixType MatrixType;
 typedef typename MatrixType::Scalar Scalar;
 typedef Eigen::RealSchur<MatrixType> Solver;

 template <class PyClass>
 void visit(PyClass& cl) const {
 cl.def(
 bp::init<Eigen::DenseIndex>(bp::arg("size"), "Default constructor. "))
 .def(bp::init<MatrixType, bp::optional<bool>>(
 bp::args("matrix", "computeU"),
 "Constructor; computes real Schur decomposition of given matrix. "))

 .def("compute", &RealSchurVisitor::compute_proxy<MatrixType>,
 bp::args("self", "matrix"),
 "Computes Schur decomposition of given matrix. ",
 bp::return_self<>())
 .def("compute",
 (Solver &
 (Solver::*)(const Eigen::EigenBase<MatrixType>& matrix, bool)) &
 Solver::compute,
 bp::args("self", "matrix", "computeEigenvectors"),
 "Computes Schur decomposition of given matrix. ",
 bp::return_self<>())

 .def("computeFromHessenberg",
 (Solver & (Solver::*)(const MatrixType& matrixH,
 const MatrixType& matrixQ, bool)) &
 Solver::computeFromHessenberg,
 bp::args("self", "matrixH", "matrixQ", "computeU"),
 "Compute Schur decomposition from a given Hessenberg matrix. ",
 bp::return_self<>())

 .def("info", &Solver::info, bp::arg("self"),
 "NumericalIssue if the input contains INF or NaN values or "
 "overflow occured. Returns Success otherwise.")

 .def("matrixT", &Solver::matrixT, bp::arg("self"),
 "Returns the quasi-triangular matrix in the Schur decomposition.",
 bp::return_value_policy<bp::copy_const_reference>())
 .def("matrixU", &Solver::matrixU, bp::arg("self"),
 "Returns the orthogonal matrix in the Schur decomposition. ",
 bp::return_value_policy<bp::copy_const_reference>())

 .def("setMaxIterations", &Solver::setMaxIterations,
 bp::args("self", "max_iter"),
 "Sets the maximum number of iterations allowed.",
 bp::return_self<>())
 .def("getMaxIterations", &Solver::getMaxIterations, bp::arg("self"),
 "Returns the maximum number of iterations.");
 }

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

 static void expose(const std::string& name) {
 bp::class_<Solver>(name.c_str(), bp::no_init)
 .def(RealSchurVisitor())
 .def(IdVisitor<Solver>());
 }

 private:
 template <typename MatrixType>
 static Solver& compute_proxy(Solver& self, const MatrixType& A) {
 return self.compute(A);
 }
};

} // namespace eigenpy

#endif // ifndef __eigenpy_decompositions_generalized_real_schur_hpp__