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Update one cell, i.e. More...

Inheritance diagram for exahype2.solvers.rkfd.OneSweepPerRungeKuttaStep.UpdateCell:

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Collaboration diagram for exahype2.solvers.rkfd.OneSweepPerRungeKuttaStep.UpdateCell:

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Public Member Functions
	__init__ (self, solver)
	patch: peano4.datamodel.Patch Patch which is to be used

	get_includes (self)
	Return include statements that you need.

Public Member Functions inherited from peano4.toolbox.blockstructured.ReconstructPatchAndApplyFunctor.ReconstructPatchAndApplyFunctor
	get_constructor_body (self)
	Define a tailored constructor body.

	get_action_set_name (self)
	Return unique action set name.

	user_should_modify_template (self)
	Is the user allowed to modify the output.

	get_body_of_operation (self, operation_name)
	Return actual C++ code snippets to be inserted into C++ code.

	get_attributes (self)
	Return attributes as copied and pasted into the generated class.

Public Member Functions inherited from peano4.solversteps.ActionSet.ActionSet
	get_static_initialisations (self, full_qualified_classname)

	get_destructor_body (self)

	get_body_of_getGridControlEvents (self)

	get_body_of_prepareTraversal (self)

	get_body_of_unprepareTraversal (self)

Static Public Attributes
	SolveRiemannProblemsOverPatch = jinja2.Template( ReconstructLinearCombination + )

Static Public Attributes inherited from peano4.solversteps.ActionSet.ActionSet
str	OPERATION_BEGIN_TRAVERSAL = "beginTraversal"

str	OPERATION_END_TRAVERSAL = "endTraversal"

str	OPERATION_CREATE_PERSISTENT_VERTEX = "createPersistentVertex"

str	OPERATION_DESTROY_PERSISTENT_VERTEX = "destroyPersistentVertex"

str	OPERATION_CREATE_HANGING_VERTEX = "createHangingVertex"

str	OPERATION_DESTROY_HANGING_VERTEX = "destroyHangingVertex"

str	OPERATION_CREATE_PERSISTENT_FACE = "createPersistentFace"

str	OPERATION_DESTROY_PERSISTENT_FACE = "destroyPersistentFace"

str	OPERATION_CREATE_HANGING_FACE = "createHangingFace"

str	OPERATION_DESTROY_HANGING_FACE = "destroyHangingFace"

str	OPERATION_CREATE_CELL = "createCell"

str	OPERATION_DESTROY_CELL = "destroyCell"

str	OPERATION_TOUCH_VERTEX_FIRST_TIME = "touchVertexFirstTime"

str	OPERATION_TOUCH_VERTEX_LAST_TIME = "touchVertexLastTime"

str	OPERATION_TOUCH_FACE_FIRST_TIME = "touchFaceFirstTime"

str	OPERATION_TOUCH_FACE_LAST_TIME = "touchFaceLastTime"

str	OPERATION_TOUCH_CELL_FIRST_TIME = "touchCellFirstTime"

str	OPERATION_TOUCH_CELL_LAST_TIME = "touchCellLastTime"

Protected Member Functions
	_add_action_set_entries_to_dictionary (self, d)
	This is our plug-in point to alter the underlying dictionary.

Protected Attributes
	_solver

	_Template_TouchCellFirstTime_Preamble

	_butcher_tableau

Additional Inherited Members
Data Fields inherited from peano4.toolbox.blockstructured.ReconstructPatchAndApplyFunctor.ReconstructPatchAndApplyFunctor
	guard

	no_of_unknowns

	dofs_per_axis

	total_overlap

	overlap_name

	patch_name

	functor_implementation

	add_assertions_to_halo_exchange

	reconstructed_array_memory_location

Data Fields inherited from peano4.solversteps.ActionSet.ActionSet
	descend_invocation_order

	parallel

Static Protected Attributes inherited from peano4.toolbox.blockstructured.ReconstructPatchAndApplyFunctor.ReconstructPatchAndApplyFunctor
str	_Template_TouchCellFirstTime_Preamble

str	_Template_TouchCellFirstTime_Fill_Patch

str	_Template_TouchCellFirstTime_Fill_Halos

str	_Template_TouchCellFirstTime_Core

str	_Template_TouchCellFirstTime_Epilogue

Detailed Description

Update one cell, i.e.

compute Runge-Kutta step on it

This routine is very similar to the Finite Volume step. The big difference in the context of Runge-Kutta is that we always have to construct a linear combination of the input data and then write the new estimate for the right-hand side into the large estimate field.

So we operate in two steps: First, we let the default block-structured code reconstruct the old time step data. After that, we add the rhs estimates onto this reconstructed data. The latter can be read as a correction step to the reconstructed values. It is correct if and only if the haloes are properly initialised with a corrected value, as we cannot correct the halo data at this point.

Correction terms with Runge-Kutta trials

We current the values with a linear combination of all of the estimates according to the Butcher Tableau.

The linear combination is a volumetric representation which includes both the degrees of freedom and the auxiliary variables. However, the auxiliary variables are not developing over time. In Runge-Kutta, I have estimates for the right-hand side, i.e. for the derivatives

\( \partial _t Q = F(Q) \)

This is the stuff stored in RhsEstimates. It does not comprise any auxiliary variables. So I have to copy the auxiliary variables from the last valid time step every time I reconstruct a new guess.

Definition at line 72 of file OneSweepPerRungeKuttaStep.py.

Constructor & Destructor Documentation

◆ init()

exahype2.solvers.rkfd.OneSweepPerRungeKuttaStep.UpdateCell.__init__	(		self,
			patch )

patch: peano4.datamodel.Patch Patch which is to be used

patch_overlap: peano4.datamodel.Patch Consult remark above about how the dimensions of this overlap patch have to match

Functor_implementation

The functor implementation is a plain C/C++

If you want to use brackets in your implementation, please use double brackets {{ }} as the template system otherwise gets confused.
The following C++ variables are defined:

oldQWithHalo newQ

Both are plain double pointers.

Data validation

I use quite a lot of validitiy checks for the copied data via comparison to its self. This way, I can at least spot nans. I use the dictionary entries ASSERTION_WITH_X_ARGUMENTS to realise this, and they are, by default, set to Peano's assertion macros. You can redefine them.

Reimplemented from peano4.toolbox.blockstructured.ReconstructPatchAndApplyFunctor.ReconstructPatchAndApplyFunctor.

Definition at line 133 of file OneSweepPerRungeKuttaStep.py.