.. _program_listing_file__tmp_ws_src_eigenpy_include_eigenpy_solvers_BasicPreconditioners.hpp:

Program Listing for File BasicPreconditioners.hpp
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|exhale_lsh| :ref:`Return to documentation for file <file__tmp_ws_src_eigenpy_include_eigenpy_solvers_BasicPreconditioners.hpp>` (``/tmp/ws/src/eigenpy/include/eigenpy/solvers/BasicPreconditioners.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /*
    * Copyright 2017, Justin Carpentier, LAAS-CNRS
    *
    * This file is part of eigenpy.
    * eigenpy is free software: you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public License
    * as published by the Free Software Foundation, either version 3 of
    * the License, or (at your option) any later version.
    * eigenpy is distributed in the hope that it will be
    * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
    * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    * GNU Lesser General Public License for more details.  You should
    * have received a copy of the GNU Lesser General Public License along
    * with eigenpy.  If not, see <http://www.gnu.org/licenses/>.
    */
   
   #ifndef __eigenpy_basic_preconditioners_hpp__
   #define __eigenpy_basic_preconditioners_hpp__
   
   #include <Eigen/IterativeLinearSolvers>
   
   #include "eigenpy/fwd.hpp"
   
   namespace eigenpy {
   
   template <typename Preconditioner>
   struct PreconditionerBaseVisitor
       : public bp::def_visitor<PreconditionerBaseVisitor<Preconditioner> > {
     typedef Eigen::MatrixXd MatrixType;
     typedef Eigen::VectorXd VectorType;
   
     template <class PyClass>
     void visit(PyClass& cl) const {
       cl.def(bp::init<>("Default constructor"))
           .def(bp::init<MatrixType>(bp::args("self", "A"),
                                     "Initialize the preconditioner with matrix A "
                                     "for further Az=b solving."))
   #if EIGEN_VERSION_AT_LEAST(3, 3, 0)
           .def("info", &Preconditioner::info,
                "Returns success if the Preconditioner has been well initialized.")
   #endif
           .def("solve", &solve, bp::arg("b"),
                "Returns the solution A * z = b where the preconditioner is an "
                "estimate of A^-1.")
   
           .def("compute", &Preconditioner::template compute<MatrixType>,
                bp::arg("mat"),
                "Initialize the preconditioner from the matrix value.",
                bp::return_value_policy<bp::reference_existing_object>())
           .def("factorize", &Preconditioner::template factorize<MatrixType>,
                bp::arg("mat"),
                "Initialize the preconditioner from the matrix value, i.e "
                "factorize the mat given as input to approximate its inverse.",
                bp::return_value_policy<bp::reference_existing_object>());
     }
   
    private:
     static VectorType solve(Preconditioner& self, const VectorType& b) {
       return self.solve(b);
     }
   };
   
   template <typename Scalar>
   struct DiagonalPreconditionerVisitor
       : PreconditionerBaseVisitor<Eigen::DiagonalPreconditioner<Scalar> > {
     typedef Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic> MatrixType;
     typedef Eigen::DiagonalPreconditioner<Scalar> Preconditioner;
   
     template <class PyClass>
     void visit(PyClass& cl) const {
       cl.def(PreconditionerBaseVisitor<Preconditioner>())
           .def("rows", &Preconditioner::rows,
                "Returns the number of rows in the preconditioner.")
           .def("cols", &Preconditioner::cols,
                "Returns the number of cols in the preconditioner.");
     }
   
     static void expose() {
       bp::class_<Preconditioner>(
           "DiagonalPreconditioner",
           "A preconditioner based on the digonal entrie.\n"
           "This class allows to approximately solve for A.x = b problems "
           "assuming A is a diagonal matrix.",
           bp::no_init);
     }
   };
   
   #if EIGEN_VERSION_AT_LEAST(3, 3, 5)
   template <typename Scalar>
   struct LeastSquareDiagonalPreconditionerVisitor
       : PreconditionerBaseVisitor<
             Eigen::LeastSquareDiagonalPreconditioner<Scalar> > {
     typedef Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic> MatrixType;
     typedef Eigen::LeastSquareDiagonalPreconditioner<Scalar> Preconditioner;
   
     template <class PyClass>
     void visit(PyClass&) const {}
   
     static void expose() {
       bp::class_<Preconditioner>(
           "LeastSquareDiagonalPreconditioner",
           "Jacobi preconditioner for LeastSquaresConjugateGradient.\n"
           "his class allows to approximately solve for A' A x  = A' b problems "
           "assuming A' A is a diagonal matrix.",
           bp::no_init)
           .def(DiagonalPreconditionerVisitor<Scalar>());
     }
   };
   #endif
   
   struct IdentityPreconditionerVisitor
       : PreconditionerBaseVisitor<Eigen::IdentityPreconditioner> {
     typedef Eigen::IdentityPreconditioner Preconditioner;
   
     template <class PyClass>
     void visit(PyClass&) const {}
   
     static void expose() {
       bp::class_<Preconditioner>("IdentityPreconditioner", bp::no_init)
           .def(PreconditionerBaseVisitor<Preconditioner>());
     }
   };
   
   }  // namespace eigenpy
   
   #endif  // ifndef __eigenpy_basic_preconditioners_hpp__