GinkgoWrappers::SolverBase< ValueType, IndexType > Class Template Reference

#include <deal.II/lac/ginkgo_solver.h>

Detailed Description

template<typename ValueType, typename IndexType>
class GinkgoWrappers::SolverBase< ValueType, IndexType >

This class forms the base class for all of Ginkgo's iterative solvers. The various derived classes only take the additional data that is specific to them and solve the given linear system. The entire collection of solvers that Ginkgo implements is available at documentation and manual pages.

Definition at line 48 of file ginkgo_solver.h.

Inheritance diagram for GinkgoWrappers::SolverBase< ValueType, IndexType >:

Public Member Functions
	SolverBase (SolverControl &solver_control, const std::string &exec_type)
virtual	~SolverBase ()=default
void	initialize (const SparseMatrix< ValueType > &matrix)
void	apply (Vector< ValueType > &solution, const Vector< ValueType > &rhs)
void	solve (const SparseMatrix< ValueType > &matrix, Vector< ValueType > &solution, const Vector< ValueType > &rhs)
SolverControl &	control () const

Protected Attributes
SolverControl &	solver_control
std::shared_ptr< gko::LinOpFactory >	solver_gen
std::shared_ptr< gko::stop::ResidualNormReduction<>::Factory >	residual_criterion
std::shared_ptr< gko::log::Convergence<> >	convergence_logger
std::shared_ptr< gko::stop::Combined::Factory >	combined_factory
std::shared_ptr< gko::Executor >	executor

Private Member Functions
void	initialize_ginkgo_log ()

Private Attributes
std::shared_ptr< gko::matrix::Csr< ValueType, IndexType > >	system_matrix
const std::string	exec_type

Constructor & Destructor Documentation

SolverBase()

template<typename ValueType , typename IndexType >

SolverBase< ValueType, IndexType >::SolverBase	(	SolverControl &	solver_control,
		const std::string &	exec_type
	)

Constructor.

The exec_type defines the paradigm where the solution is computed. It is a string and the choices are "omp" , "reference" or "cuda". The respective strings create the respective executors as given below.

Ginkgo currently supports three different executor types:

• OmpExecutor specifies that the data should be stored and the associated operations executed on an OpenMP-supporting device (e.g. host CPU);

  auto omp = gko::create<gko::OmpExecutor>();

• CudaExecutor specifies that the data should be stored and the operations executed on the NVIDIA GPU accelerator;

  if(gko::CudaExecutor::get_num_devices() > 0 ) {
     auto cuda = gko::create<gko::CudaExecutor>();
  }

• ReferenceExecutor executes a non-optimized reference implementation, which can be used to debug the library.

  auto ref = gko::create<gko::ReferenceExecutor>();

The following code snippet demonstrates the using of the OpenMP executor to create a solver which would use the OpenMP paradigm to the solve the system on the CPU.

auto omp = gko::create<gko::OmpExecutor>();
using cg = gko::solver::Cg<>;
auto solver_gen =
    cg::build()
         .with_criteria(
             gko::stop::Iteration::build().with_max_iters(20u).on(omp),
             gko::stop::ResidualNormReduction<>::build()
                 .with_reduction_factor(1e-6)
                 .on(omp))
         .on(omp);
auto solver = solver_gen->generate(system_matrix);
 
solver->apply(lend(rhs), lend(solution));

The solver_control object is the same as for other deal.II iterative solvers.

Definition at line 33 of file ginkgo_solver.cc.

~SolverBase()

template<typename ValueType , typename IndexType >

virtual GinkgoWrappers::SolverBase< ValueType, IndexType >::~SolverBase ( )

virtualdefault

Destructor.

Member Function Documentation

initialize()

template<typename ValueType , typename IndexType >

void SolverBase< ValueType, IndexType >::initialize

(

const SparseMatrix< ValueType > &

matrix

)

Initialize the matrix and copy over its data to Ginkgo's data structures.

Definition at line 217 of file ginkgo_solver.cc.

apply()

template<typename ValueType , typename IndexType >

void SolverBase< ValueType, IndexType >::apply	(	Vector< ValueType > &	solution,
		const Vector< ValueType > &	rhs
	)

Solve the linear system Ax=b. Dependent on the information provided by derived classes one of Ginkgo's linear solvers is chosen.

Definition at line 87 of file ginkgo_solver.cc.

solve()

template<typename ValueType , typename IndexType >

void SolverBase< ValueType, IndexType >::solve	(	const SparseMatrix< ValueType > &	matrix,
		Vector< ValueType > &	solution,
		const Vector< ValueType > &	rhs
	)

Solve the linear system Ax=b. Dependent on the information provided by derived classes one of Ginkgo's linear solvers is chosen.

Definition at line 291 of file ginkgo_solver.cc.

control()

template<typename ValueType , typename IndexType >

SolverControl & SolverBase< ValueType, IndexType >::control

(

)

const

Access to the object that controls convergence.

Definition at line 208 of file ginkgo_solver.cc.

initialize_ginkgo_log()

template<typename ValueType , typename IndexType >

void SolverBase< ValueType, IndexType >::initialize_ginkgo_log ( )

private

Initialize the Ginkgo logger object with event masks. Refer to Ginkgo's logging event masks.

Definition at line 75 of file ginkgo_solver.cc.

Member Data Documentation

solver_control

template<typename ValueType , typename IndexType >

SolverControl& GinkgoWrappers::SolverBase< ValueType, IndexType >::solver_control

protected

Reference to the object that controls convergence of the iterative solvers.

Definition at line 146 of file ginkgo_solver.h.

solver_gen

template<typename ValueType , typename IndexType >

std::shared_ptr<gko::LinOpFactory> GinkgoWrappers::SolverBase< ValueType, IndexType >::solver_gen

protected

The Ginkgo generated solver factory object.

Definition at line 151 of file ginkgo_solver.h.

residual_criterion

template<typename ValueType , typename IndexType >

std::shared_ptr<gko::stop::ResidualNormReduction<>::Factory> GinkgoWrappers::SolverBase< ValueType, IndexType >::residual_criterion

protected

The residual criterion object that controls the reduction of the residual based on the tolerance set in the solver_control member.

Definition at line 158 of file ginkgo_solver.h.

convergence_logger

template<typename ValueType , typename IndexType >

std::shared_ptr<gko::log::Convergence<> > GinkgoWrappers::SolverBase< ValueType, IndexType >::convergence_logger

protected

The Ginkgo convergence logger used to check for convergence and other solver data if needed.

Definition at line 164 of file ginkgo_solver.h.

combined_factory

template<typename ValueType , typename IndexType >

std::shared_ptr<gko::stop::Combined::Factory> GinkgoWrappers::SolverBase< ValueType, IndexType >::combined_factory

protected

The Ginkgo combined factory object is used to create a combined stopping criterion to be passed to the solver.

Definition at line 170 of file ginkgo_solver.h.

executor

template<typename ValueType , typename IndexType >

std::shared_ptr<gko::Executor> GinkgoWrappers::SolverBase< ValueType, IndexType >::executor

protected

The execution paradigm in Ginkgo. The choices are between gko::OmpExecutor, gko::CudaExecutor and gko::ReferenceExecutor and more details can be found in Ginkgo's documentation.

Definition at line 177 of file ginkgo_solver.h.

system_matrix

template<typename ValueType , typename IndexType >

std::shared_ptr<gko::matrix::Csr<ValueType, IndexType> > GinkgoWrappers::SolverBase< ValueType, IndexType >::system_matrix

private

Ginkgo matrix data structure. First template parameter is for storing the array of the non-zeros of the matrix. The second is for the row pointers and the column indices.

Todo:

Templatize based on Matrix type.

Definition at line 196 of file ginkgo_solver.h.

exec_type

template<typename ValueType , typename IndexType >

const std::string GinkgoWrappers::SolverBase< ValueType, IndexType >::exec_type

private

The execution paradigm as a string to be set by the user. The choices are between omp, cuda and reference and more details can be found in Ginkgo's documentation.

Definition at line 203 of file ginkgo_solver.h.

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The documentation for this class was generated from the following files:

• include/deal.II/lac/ginkgo_solver.h
• source/lac/ginkgo_solver.cc