mpi2

solver_cg.hh
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			/**
			* @file solver_cg.hh
			*
			* @author Till Junge <till.junge@epfl.ch>
			*
			* @date 20 Dec 2017
			*
			* @brief class for a simple implementation of a conjugate gradient
			* solver. This follows algorithm 5.2 in Nocedal's Numerical
			* Optimization (p 112)
			*
			* Copyright © 2017 Till Junge
			*
			* µSpectre is free software; you can redistribute it and/or
			* modify it under the terms of the GNU General Public License as
			* published by the Free Software Foundation, either version 3, or (at
			* your option) any later version.
			*
			* µSpectre 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
			* General Public License for more details.
			*
			* You should have received a copy of the GNU General Public License
			* along with GNU Emacs; see the file COPYING. If not, write to the
			* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
			* Boston, MA 02111-1307, USA.
			*/

			#ifndef SOLVER_CG_H
			#define SOLVER_CG_H

			#include "solver/solver_base.hh"
			#include "common/field.hh"

			#include <functional>

			namespace muSpectre {

			/**
			* implements the `muSpectre::SolverBase` interface using a
			* conjugate gradient solver. This particular class is useful for
			* trouble shooting, as it can be made very verbose, but for
			* production runs, it is probably better to use
			* `muSpectre::SolverCGEigen`.
			*/
			template <Dim_t DimS, Dim_t DimM=DimS>
			class SolverCG: public SolverBase<DimS, DimM>
			{
			public:
			using Parent = SolverBase<DimS, DimM>; //!< base class
			//! Input vector for solvers
			using SolvVectorIn = typename Parent::SolvVectorIn;
			//! Input vector for solvers
			using SolvVectorInC = typename Parent::SolvVectorInC;
			//! Output vector for solvers
			using SolvVectorOut = typename Parent::SolvVectorOut;
			using Cell_t = typename Parent::Cell_t; //!< cell type
			using Ccoord = typename Parent::Ccoord; //!< cell coordinates type
			//! kind of tangent that is required
			using Tg_req_t = typename Parent::TangentRequirement;
			//! cg only needs to handle fields that look like strain and stress
			using Field_t = TensorField<
			typename Parent::Collection_t, Real, secondOrder, DimM>;

			//! conjugate gradient needs directional stiffness
			constexpr static Tg_req_t tangent_requirement{Tg_req_t::NeedEffect};
			//! Default constructor
			SolverCG() = delete;

			//! Constructor with domain resolutions, etc,
			SolverCG(Cell_t& cell, Real tol, Uint maxiter=0, bool verbose =false);

			//! Copy constructor
			SolverCG(const SolverCG &other) = delete;

			//! Move constructor
			SolverCG(SolverCG &&other) = default;

			//! Destructor
			virtual ~SolverCG() = default;

			//! Copy assignment operator
			SolverCG& operator=(const SolverCG &other) = delete;

			//! Move assignment operator
			SolverCG& operator=(SolverCG &&other) = default;

			bool has_converged() const override final {return this->converged;}

			//! actual solver
			void solve(const Field_t & rhs,
			Field_t & x);

			// this simplistic implementation has no initialisation phase so the default is ok

			SolvVectorOut solve(const SolvVectorInC rhs, SolvVectorIn x_0) override final;

			std::string name() const override final {return "CG";}

			protected:
			//! returns `muSpectre::Tg_req_t::NeedEffect`
			Tg_req_t get_tangent_req() const override final;
			Field_t & r_k; //!< residual
			Field_t & p_k; //!< search direction
			Field_t & Ap_k; //!< effect of tangent on search direction
			bool converged{false}; //!< whether the solver has converged
			private:
			};

			} // muSpectre

			#endif /* SOLVER_CG_H */

muSpectre/src/solver/solver_cg.hh9e8c21080050feat/mpi2

solver_cg.hhView Options

muSpectre/src/solver/solver_cg.hh
9e8c21080050feat/mpi2

solver_cg.hh
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