#include <DGOperator.hpp>

Inheritance diagram for hyteg::dg::DGOperator:

Collaboration diagram for hyteg::dg::DGOperator:

Public Types
typedef DGFunction< real_t >	dstType

typedef DGFunction< real_t >	srcType

Public Member Functions
	DGOperator (const std::shared_ptr< PrimitiveStorage > &storage, uint_t minLevel, uint_t maxLevel, const std::shared_ptr< DGForm > &form)

void	apply (const DGFunction< real_t > &src, const DGFunction< real_t > &dst, size_t level, DoFType flag, UpdateType updateType) const override

void	enableTiming (const std::shared_ptr< walberla::WcTimingTree > &timingTree)

virtual void	gemv (const typename SourceFunction::valueType &alpha, const DGFunction< real_t > &src, const typename DestinationFunction::valueType &beta, const DGFunction< real_t > &dst, size_t level, DoFType flag) const
	Implements the BLAS level 2 routine gemv:

uint_t	getMaxLevel () const

uint_t	getMinLevel () const

const std::shared_ptr< PrimitiveStorage >	getStorage () const

void	toMatrix (const std::shared_ptr< SparseMatrixProxy > &mat, const DGFunction< idx_t > &src, const DGFunction< idx_t > &dst, size_t level, DoFType flag) const override

virtual void	toMatrix (const std::shared_ptr< SparseMatrixProxy > &mat, const typename srcType::template FunctionType< idx_t > &src, const typename dstType::template FunctionType< idx_t > &dst, size_t level, DoFType flag) const

Protected Member Functions
void	startTiming (const std::string &timerString) const

void	stopTiming (const std::string &timerString) const

Protected Attributes
const uint_t	maxLevel_

const uint_t	minLevel_

const std::shared_ptr< PrimitiveStorage >	storage_

std::shared_ptr< walberla::WcTimingTree >	timingTree_

Private Member Functions
template<typename VType >
void	addLocalToGlobalMatrix (int dim, int numSrcDofs, int numDstDofs, VType srcDofMemory, VType dstDofMemory, VolumeDoFMemoryLayout srcMemLayout, VolumeDoFMemoryLayout dstMemLayout, Index srcElementIdx, Index dstElementIdx, uint_t srcMicroVolType, uint_t dstMicroVolType, uint_t level, std::shared_ptr< SparseMatrixProxy > mat, const MatrixXr &localMat) const
	Just a small helper method that writes the local matrix into the global sparse system.

template<typename VType >
void	assembleAndOrApply (const DGFunction< VType > &src, const DGFunction< VType > &dst, size_t level, DoFType flag, const std::shared_ptr< SparseMatrixProxy > &mat, UpdateType updateType=Replace) const
	Helper function that can be used to either apply the operator, or to assemble the sparse matrix.

Private Attributes
std::shared_ptr< DGForm >	form_

Member Typedef Documentation

◆ dstType

typedef DGFunction< real_t > hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::dstType

inherited

◆ srcType

typedef DGFunction< real_t > hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::srcType

inherited

Constructor & Destructor Documentation

◆ DGOperator()

hyteg::dg::DGOperator::DGOperator	(	const std::shared_ptr< PrimitiveStorage > &	storage,
		uint_t	minLevel,
		uint_t	maxLevel,
		const std::shared_ptr< DGForm > &	form )

Member Function Documentation

◆ addLocalToGlobalMatrix()

template<typename VType >

void hyteg::dg::DGOperator::addLocalToGlobalMatrix	(	int	dim,
		int	numSrcDofs,
		int	numDstDofs,
		VType *	srcDofMemory,
		VType *	dstDofMemory,
		VolumeDoFMemoryLayout	srcMemLayout,
		VolumeDoFMemoryLayout	dstMemLayout,
		Index	srcElementIdx,
		Index	dstElementIdx,
		uint_t	srcMicroVolType,
		uint_t	dstMicroVolType,
		uint_t	level,
		std::shared_ptr< SparseMatrixProxy >	mat,
		const MatrixXr &	localMat ) const

inlineprivate

Just a small helper method that writes the local matrix into the global sparse system.

◆ apply()

void hyteg::dg::DGOperator::apply	(	const DGFunction< real_t > &	src,
		const DGFunction< real_t > &	dst,
		size_t	level,
		DoFType	flag,
		UpdateType	updateType ) const

overridevirtual

Reimplemented from hyteg::Operator< DGFunction< real_t >, DGFunction< real_t > >.

◆ assembleAndOrApply()

template<typename VType >

void hyteg::dg::DGOperator::assembleAndOrApply	(	const DGFunction< VType > &	src,
		const DGFunction< VType > &	dst,
		size_t	level,
		DoFType	flag,
		const std::shared_ptr< SparseMatrixProxy > &	mat,
		UpdateType	updateType = Replace ) const

inlineprivate

Helper function that can be used to either apply the operator, or to assemble the sparse matrix.

Since about 99% of the implementation is equal, it makes sense to fuse that here.

Which operation is performed depends on the pointer to the sparse matrix proxy and the value type. If the pointer is a nullptr, apply is executed.

Some notes on the implementation:

For DG implementations there are two main possibilities to evaluate the interface integrals.

The "naive" (not necessarily worse) approach is to loop over all interfaces in a dedicated loop e.g. after evaluating all volume integrals. Alternatively, the interface integrals are evaluated during the loop over the volumes.

This function implements the latter, with the advantage that each DoF is only written to exactly once, also there is only a single loop over the macro-volume. On the downside, each interface integral has to be evaluated twice.

A nice description is found in

Kronbichler, M., & Kormann, K. (2019). Fast matrix-free evaluation of discontinuous Galerkin finite element operators. ACM Transactions on Mathematical Software (TOMS), 45(3), 1-40.

◆ enableTiming()

void hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::enableTiming ( const std::shared_ptr< walberla::WcTimingTree > & timingTree )

inlineinherited

◆ gemv()

virtual void hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::gemv	(	const typename SourceFunction::valueType &	alpha,
		const DGFunction< real_t > &	src,
		const typename DestinationFunction::valueType &	beta,
		const DGFunction< real_t > &	dst,
		size_t	level,
		DoFType	flag ) const

inlinevirtualinherited

Implements the BLAS level 2 routine gemv:

y ← ɑAx + βy

where ɑ, β are scalars, A is this operator, x is the "src" function, and y is the "dst" function.

Note that the apply() method implements

y ← Ax + ɣy

where ɣ ∈ { 0, 1 } for UpdateType Replace and Add respectively. This is just a gemv with ɑ = 1 and β = ɣ.

◆ getMaxLevel()

uint_t hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::getMaxLevel ( ) const

inlineinherited

◆ getMinLevel()

uint_t hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::getMinLevel ( ) const

inlineinherited

◆ getStorage()

const std::shared_ptr< PrimitiveStorage > hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::getStorage ( ) const

inlineinherited

◆ startTiming()

void hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::startTiming ( const std::string & timerString ) const

inlineprotectedinherited

◆ stopTiming()

void hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::stopTiming ( const std::string & timerString ) const

inlineprotectedinherited

◆ toMatrix() [1/2]

void hyteg::dg::DGOperator::toMatrix	(	const std::shared_ptr< SparseMatrixProxy > &	mat,
		const DGFunction< idx_t > &	src,
		const DGFunction< idx_t > &	dst,
		size_t	level,
		DoFType	flag ) const

override

◆ toMatrix() [2/2]

virtual void hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::toMatrix	(	const std::shared_ptr< SparseMatrixProxy > &	mat,
		const typename srcType::template FunctionType< idx_t > &	src,
		const typename dstType::template FunctionType< idx_t > &	dst,
		size_t	level,
		DoFType	flag ) const

inlinevirtualinherited

Member Data Documentation

◆ form_

std::shared_ptr< DGForm > hyteg::dg::DGOperator::form_

private

◆ maxLevel_

const uint_t hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::maxLevel_

protectedinherited

◆ minLevel_

const uint_t hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::minLevel_

protectedinherited

◆ storage_

const std::shared_ptr< PrimitiveStorage > hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::storage_

protectedinherited

◆ timingTree_

std::shared_ptr< walberla::WcTimingTree > hyteg::Operator< DGFunction< real_t > , DGFunction< real_t > >::timingTree_

protectedinherited

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

src/hyteg/dgfunctionspace/DGOperator.hpp
src/hyteg/dgfunctionspace/DGOperator.cpp

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Member Typedef Documentation

◆ dstType

◆ srcType

Constructor & Destructor Documentation

◆ DGOperator()

Member Function Documentation

◆ addLocalToGlobalMatrix()

◆ apply()

◆ assembleAndOrApply()

◆ enableTiming()

◆ gemv()

◆ getMaxLevel()

◆ getMinLevel()

◆ getStorage()

◆ startTiming()

◆ stopTiming()

◆ toMatrix() [1/2]

◆ toMatrix() [2/2]

Member Data Documentation

◆ form_

◆ maxLevel_

◆ minLevel_

◆ storage_

◆ timingTree_