exahype2::fd::fd4 Namespace Reference

Namespaces
namespace	internal
namespace	omp

Enumerations
enum class	DifferentialSourceTermVariant { CentralDifferences , CentralDifferencesWithLopsidedAdvection , CentralDifferencesWithLimiter , CentralDifferencesWithLimiterAndLopsidedAdvection }

Functions
void	timeStep_patchwise_heap_functors (::exahype2::CellData< double, double > &patchData, int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant, Flux flux, NonconservativeProduct DifferentialSource, Source AlgebraicSource)
	Fourth-order Finite Differences.
void	reconstruct_first_derivatives (::exahype2::CellData< double, double > &patchData, int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables)
	Helper routine to reconstruct the first derivatives.
template<typename Solver , int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, typename TempDataEnumerator >
static void	timeStep_batched_heap_static_calls (::exahype2::CellData< double, double > &patchData, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant)
template<typename Solver , int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, typename TempDataEnumerator >
static void	timeStep_patchwise_heap_static_calls (::exahype2::CellData< double, double > &patchData, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant)
template<typename Solver , int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, typename TempDataEnumerator >
static void	timeStep_batched_heap_multicore_static_calls (::exahype2::CellData< double, double > &patchData, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant)

Enumeration Type Documentation

DifferentialSourceTermVariant

enum class exahype2::fd::fd4::DifferentialSourceTermVariant

strong

Enumerator
CentralDifferences
CentralDifferencesWithLopsidedAdvection
CentralDifferencesWithLimiter
CentralDifferencesWithLimiterAndLopsidedAdvection

Definition at line 10 of file KernelVariants.h.

Function Documentation

reconstruct_first_derivatives()

void exahype2::fd::fd4::reconstruct_first_derivatives	(	::exahype2::CellData< double, double > &	patchData,
		int	numberOfGridCellsPerPatchPerAxis,
		int	haloSize,
		int	unknowns,
		int	auxiliaryVariables )

Helper routine to reconstruct the first derivatives.

This operation computes the first derivatives over a patch due to

@Han Your call

Parameters

patchData

Container for the actual data. The pointer to old data points to the patch data plus its halo of size haloSize. The new pointer is to be befilled, i.e. it contains garbage by default. The fields timeStamp and timeStepSize here are not used, so you can set them to anything you like. The function doesn't care.

Definition at line 629 of file FD4_patchwise_functors.cpp.

References _log, assertionEquals, exahype2::CellData< inType, outType >::cellCentre, exahype2::CellData< inType, outType >::cellSize, exahype2::fd::internal::copySolution_LoopBody(), exahype2::CellData< inType, outType >::numberOfCells, exahype2::CellData< inType, outType >::QIn, and exahype2::CellData< inType, outType >::QOut.

Referenced by exahype2::fd::tests::CCZ4KernelTest::AppleWithAppleTest().

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timeStep_batched_heap_multicore_static_calls()

template<typename Solver , int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, typename TempDataEnumerator >

static void exahype2::fd::fd4::timeStep_batched_heap_multicore_static_calls ( ::exahype2::CellData< double, double > & patchData, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant )

static

timeStep_batched_heap_static_calls()

template<typename Solver , int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, typename TempDataEnumerator >

static void exahype2::fd::fd4::timeStep_batched_heap_static_calls ( ::exahype2::CellData< double, double > & patchData, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant )

static

timeStep_patchwise_heap_functors()

void exahype2::fd::fd4::timeStep_patchwise_heap_functors	(	::exahype2::CellData< double, double > &	patchData,
		int	numberOfGridCellsPerPatchPerAxis,
		int	haloSize,
		int	unknowns,
		int	auxiliaryVariables,
		double	KOSigma,
		bool	evaluateFlux,
		bool	evaluateDifferentialSource,
		bool	evaluateAlgebraicSource,
		bool	copyOldTimeStepAndScaleWithTimeStepSize,
		DifferentialSourceTermVariant	variant,
		Flux	flux,
		NonconservativeProduct	DifferentialSource,
		Source	AlgebraicSource )

Fourth-order Finite Differences.

This routine relies on the fact that we have a halo size of 3.

Enumerators

The enumerators span only one patch each, as we run through the patches one by one. It is important to recognise that the input enumerator creates indices over an array which holds auxiliary (material) parameters, while the output does not hold auxiliary ones. It solely holds the fluxes of the unknowns which are evolved according to the PDE.

Both input and output enumerator use AoS ordering.

Comparison to other solvers

Compared to the Finite Differences solver, this routine does not accept any eigenvalue. On the one hand, this is clear, as the finite differences formulation per se does not require an eigenvalue within the discretisation. On the other hand, it is important to keep in mind that the routine is used within a Runge-Kutta context, where the eigenvalue is required for adaptive time stepping after the last Runge-Kutta step, when we have actually computed the new solution. For this reason, it makes sense to outsource the eigenvalue computation to a routine of its own. Compuare to reduceMaxEigenvalue_patchwise_functors() for some details.

Arguments

Parameters

copyOldTimeStepAndScaleWithTimeStepSize	The routine can be used in two ways: Either for a classic explicit Euler or in a Runge-Kutta context. For the latter, we evaluate the outcome of the right-hand side of an ODE formulation \( \partial _t Q(t) = F(t) \), i.e. we store the F. In an Euler context, we evaluate F, too, but then immediately scale it with the time step size and add the original time step's data. We copy stuff over.
KOSigma	Penalty term for the sixth order derivative. Scales the Kreiss Oliger dissipation. If you set it to 0.0, the term is not evaluated at all.

Definition at line 9 of file FD4_patchwise_functors.cpp.

References _log, exahype2::fd::internal::addAlgebraicSourceTerm_LoopBody(), assertionEquals, exahype2::CellData< inType, outType >::cellCentre, exahype2::CellData< inType, outType >::cellSize, exahype2::fd::internal::clearSolution_LoopBody(), exahype2::fd::internal::copySolution_LoopBody(), exahype2::CellData< inType, outType >::dt, tarch::freeMemory(), tarch::Heap, logDebug, exahype2::CellData< inType, outType >::numberOfCells, exahype2::CellData< inType, outType >::QIn, exahype2::CellData< inType, outType >::QOut, exahype2::enumerator::AoSLexicographicEnumerator::size(), and exahype2::CellData< inType, outType >::t.

Referenced by exahype2::fd::tests::CCZ4KernelTest::AppleWithAppleTest().

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timeStep_patchwise_heap_static_calls()

template<typename Solver , int numberOfGridCellsPerPatchPerAxis, int haloSize, int unknowns, int auxiliaryVariables, typename TempDataEnumerator >

static void exahype2::fd::fd4::timeStep_patchwise_heap_static_calls ( ::exahype2::CellData< double, double > & patchData, double KOSigma, bool evaluateFlux, bool evaluateDifferentialSource, bool evaluateAlgebraicSource, bool copyOldTimeStepAndScaleWithTimeStepSize, DifferentialSourceTermVariant variant )

static