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non_linear_solver_petsc.cc
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/**
* @file non_linear_solver_petsc.cc
*
* @author Nicolas Richart <nicolas.richart@epfl.ch>
*
* @date creation: Sat Feb 03 2018
* @date last modification: Sat May 23 2020
*
* @brief Interface to non linear solver of PETSc
*
*
* @section LICENSE
*
* Copyright (©) 2016-2021 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
* Akantu 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.
*
* Akantu 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 Akantu. If not, see <http://www.gnu.org/licenses/>.
*
*/
/* -------------------------------------------------------------------------- */
#include "non_linear_solver_petsc.hh"
#include "dof_manager_petsc.hh"
#include "mpi_communicator_data.hh"
#include "solver_callback.hh"
#include "solver_vector_petsc.hh"
#include "sparse_matrix_petsc.hh"
/* -------------------------------------------------------------------------- */
#include <petscoptions.h>
/* -------------------------------------------------------------------------- */
namespace akantu {
NonLinearSolverPETSc::NonLinearSolverPETSc(
DOFManagerPETSc & dof_manager,
const NonLinearSolverType & non_linear_solver_type, const ID & id)
: NonLinearSolver(dof_manager, non_linear_solver_type, id),
dof_manager(dof_manager) {
std::unordered_map<NonLinearSolverType, SNESType>
petsc_non_linear_solver_types{
{NonLinearSolverType::_newton_raphson, SNESNEWTONLS},
{NonLinearSolverType::_linear, SNESKSPONLY},
{NonLinearSolverType::_gmres, SNESNGMRES},
{NonLinearSolverType::_bfgs, SNESQN},
{NonLinearSolverType::_cg, SNESNCG}};
this->has_internal_set_param = true;
for (const auto & pair : petsc_non_linear_solver_types) {
supported_type.insert(pair.first);
}
this->checkIfTypeIsSupported();
auto && mpi_comm = dof_manager.getMPIComm();
PETSc_call(SNESCreate, mpi_comm, &snes);
auto it = petsc_non_linear_solver_types.find(non_linear_solver_type);
if (it != petsc_non_linear_solver_types.end()) {
PETSc_call(SNESSetType, snes, it->second);
}
SNESSetFromOptions(snes);
}
/* -------------------------------------------------------------------------- */
NonLinearSolverPETSc::~NonLinearSolverPETSc() {
PETSc_call(SNESDestroy, &snes);
}
/* -------------------------------------------------------------------------- */
class NonLinearSolverPETScCallback {
public:
NonLinearSolverPETScCallback(DOFManagerPETSc & dof_manager, SNES snes,
SolverVectorPETSc & x)
: dof_manager(dof_manager), snes(snes), x_prev(x, "previous solution") {}
void corrector(Vec & x) {
PetscInt iteration;
PETSc_call(SNESGetIterationNumber, snes, &iteration);
if (prev_iteration == iteration) {
return;
}
prev_iteration = iteration;
auto & dx = dof_manager.getSolution();
PETSc_call(VecWAXPY, dx, -1., x_prev, x);
dof_manager.splitSolutionPerDOFs();
callback->corrector();
PETSc_call(VecCopy, x, x_prev);
}
void assembleResidual(Vec x) {
corrector(x);
callback->assembleResidual();
}
void assembleJacobian(Vec x) {
corrector(x);
callback->assembleMatrix("J");
}
void reset() { prev_iteration = -1; }
void setInitialSolution(SolverVectorPETSc & x) {
PETSc_call(VecCopy, x, x_prev);
}
void setCallback(SolverCallback & callback) { this->callback = &callback; }
private:
SolverCallback * callback;
DOFManagerPETSc & dof_manager;
SNES snes;
// SolverVectorPETSc & x;
SolverVectorPETSc x_prev;
PetscInt prev_iteration{-1};
}; // namespace akantu
/* -------------------------------------------------------------------------- */
PetscErrorCode NonLinearSolverPETSc::FormFunction(SNES /*snes*/, Vec x,
Vec /*f*/, void * ctx) {
auto * _this = reinterpret_cast<NonLinearSolverPETScCallback *>(ctx);
_this->assembleResidual(x);
return 0;
}
/* -------------------------------------------------------------------------- */
PetscErrorCode NonLinearSolverPETSc::FormJacobian(SNES /*snes*/, Vec x,
Mat /*J*/, Mat /*P*/,
void * ctx) {
auto * _this = reinterpret_cast<NonLinearSolverPETScCallback *>(ctx);
_this->assembleJacobian(x);
return 0;
}
/* -------------------------------------------------------------------------- */
void NonLinearSolverPETSc::solve(SolverCallback & callback) {
callback.beforeSolveStep();
this->dof_manager.updateGlobalBlockedDofs();
callback.assembleMatrix("J");
auto & global_x = dof_manager.getSolution();
global_x.zero();
if (not x) {
x = std::make_unique<SolverVectorPETSc>(global_x, "temporary_solution");
}
*x = global_x;
if (not ctx) {
ctx = std::make_unique<NonLinearSolverPETScCallback>(dof_manager, snes, *x);
} else {
ctx->reset();
}
ctx->setCallback(callback);
ctx->setInitialSolution(global_x);
auto & rhs = dof_manager.getResidual();
auto & J = dof_manager.getMatrix("J");
PETSc_call(SNESSetFunction, snes, rhs, NonLinearSolverPETSc::FormFunction,
ctx.get());
PETSc_call(SNESSetJacobian, snes, J, J, NonLinearSolverPETSc::FormJacobian,
ctx.get());
rhs.zero();
callback.predictor();
// callback.assembleResidual();
PETSc_call(SNESSolve, snes, nullptr, *x);
PETSc_call(SNESGetConvergedReason, snes, &reason);
PETSc_call(SNESGetIterationNumber, snes, &n_iter);
PETSc_call(VecAXPY, global_x, -1.0, *x);
dof_manager.splitSolutionPerDOFs();
callback.corrector();
bool converged = reason >= 0;
callback.afterSolveStep(converged);
if (not converged) {
PetscReal atol;
PetscReal rtol;
PetscReal stol;
PetscInt maxit;
PetscInt maxf;
PETSc_call(SNESGetTolerances, snes, &atol, &rtol, &stol, &maxit, &maxf);
AKANTU_CUSTOM_EXCEPTION(debug::SNESNotConvergedException(
this->reason, this->n_iter, stol, atol, rtol, maxit));
}
}
/* -------------------------------------------------------------------------- */
void NonLinearSolverPETSc::set_param(const ID & param,
const std::string & value) {
std::map<ID, ID> akantu_to_petsc_option = {{"max_iterations", "snes_max_it"},
{"threshold", "snes_stol"}};
auto it = akantu_to_petsc_option.find(param);
auto p = it == akantu_to_petsc_option.end() ? param : it->second;
PetscOptionsSetValue(nullptr, p.c_str(), value.c_str());
SNESSetFromOptions(snes);
PetscOptionsClear(nullptr);
}
/* -------------------------------------------------------------------------- */
void NonLinearSolverPETSc::parseSection(const ParserSection & section) {
auto parameters = section.getParameters();
for (auto && param : range(parameters.first, parameters.second)) {
PetscOptionsSetValue(nullptr, param.getName().c_str(),
param.getValue().c_str());
}
SNESSetFromOptions(snes);
PetscOptionsClear(nullptr);
}
} // namespace akantu

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