Set the ghost grid cells along the domain boundary through the solver's exahype2.api.DirichletBoundaryConditions term. More...

Inheritance diagram for exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions:

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Collaboration diagram for exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions:

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Public Member Functions
	__init__ (self, solver, patch_overlap, guard, relative_time_step_size=0.0)

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

	get_guard_of_operation (self, operation_name)
	Return the guard of an operation.

	get_action_set_name (self)
	Return unique action set name.

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

	get_includes (self)
	Return include statements that you need.

Public Member Functions inherited from peano4.api.solversteps.ActionSet.ActionSet
	get_constructor_body (self)
	Define a tailored constructor body.

	get_static_initialisations (self, full_qualified_classname)

	get_destructor_body (self)

	get_body_of_createGridControlEventsForNextTraversal (self)
	Return the grid control events that this action set wants to trigger.

	get_implementation_of_createGridControlEventsForNextTraversal (self)
	Return the C++ implementation of createGridControlEventsForNextTraversal()

	get_body_of_prepareTraversal (self)

	get_implementation_of_prepareTraversal (self)
	Return the C++ implementation of prepareTraversal()

	get_body_of_unprepareTraversal (self)

	get_implementation_of_unprepareTraversal (self)
	Return the C++ implementation of unprepareTraversal()

	get_implementation_of_operation (self, operation_name)
	Return the C++ implementation of an operation.

bool	may_run_in_background_task (self)
	May a task graph compiler move touchCellFirstTime() into a task.

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

Static Public Member Functions
	add_task_to_time_step (solver, exahype2_project, time_step, reconstruction_task, name_suffix="", relative_time_step_size=0.0, additional_guard="true")
	Add the boundary task in front of the reconstruction of the halo.

Data Fields
	guard

	d

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

	parallel

Static Public Attributes
	TemplateTouchFaceFirstTime

Static Public Attributes inherited from peano4.api.solversteps.ActionSet.ActionSet
int	descend_invocation_order = 0

bool	parallel = False

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 Attributes
	_solver

Detailed Description

Set the ghost grid cells along the domain boundary through the solver's exahype2.api.DirichletBoundaryConditions term.

The action set plugs into touchFaceFirstTime() and delegates to exahype2::blockstructured::applyDirichletBoundaryConditions(), which holds the logic described below. Each face carries an overlap of 2*overlap grid cells along its normal (solver._patch_overlap_current_time_step), i.e. 2*HALO_SIZE for the fourth-order Finite Differences of exahype2.api.rkfd4 : the left half belongs to the cell left of the face, the right half to the cell right of it. On the domain boundary, one of these two cells lies outside of the domain. Nobody ever writes its half of the face data. This action set fills exactly this half: For each of the outside's grid cells, it invokes

repositories::<solver>.dirichletBoundaryConditions( x, t, Q );

with x being the centre of the (ghost) grid cell and t the time stamp of the Runge-Kutta stage, i.e. the solver's current time stamp getMinTimeStamp() plus relative_time_step_size times its time step size getMinTimeStepSize(). Faces along periodic axes are skipped (PeriodicBC from the project's Constants.h). Whether a face is on the domain boundary is derived from its position, i.e. compared against DomainOffset and DomainOffset+DomainSize.

The subsequent reconstruction (toolbox.blockstructured.api.ReconstructPatchWithHalo) reads the face data in touchCellFirstTime(). As Peano touches all faces of a cell for the first time before it enters the cell, the boundary task and the reconstruction can share one mesh traversal (peano4.api.taskgraph.compiler.FuseSteps.translate()).

Use add_task_to_time_step() to add the corresponding task to a time step's task graph.

Why Dirichlet conditions are not part of the roll over

exahype2.api.SommerfeldBoundaryConditions do without a boundary task: They advance the ghost cells within the roll over of the face data after the projection. Dirichlet conditions could be realised the same way, as the roll over could evaluate the boundary values at the time stamp of the next update. We deliberately keep them as a separate task which runs directly before the reconstruction, as this will not work anymore once we support local time stepping: With local time stepping, each cell advances with its own time step size, and the time stamp at which the ghost cells have to hold the boundary values is only known once the adjacent cell starts its next update, but not when the face data are rolled over after its previous update.

The class mirrors exahype2.api.fv.actionsets.ApplyDirichletBoundaryConditions, as rkfd4 does not depend on the Finite Volume package. Both share the C++ routine. Different to the Finite Volume version, it evaluates the boundary values at the time stamp of the Runge-Kutta stage. With the time stamp of the time step instead, all stages would see the same boundary values, and the scheme would drop to first order along the boundary.

Definition at line 13 of file ApplyDirichletBoundaryConditions.py.

Constructor & Destructor Documentation

◆ init()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.__init__	(	self,
		solver,
		patch_overlap,
		guard,
		relative_time_step_size = `0.0`
	)

Parameters

solver	exahype2.api.Solver The solver whose dirichletBoundaryConditions() is invoked.
patch_overlap	peano4.api.datamodel.Patch The face data to set, i.e. solver._patch_overlap_current_time_step. Its dim[0] is twice the overlap, its dim[1] the number of grid cells per axis of the cell patch.
guard	str C++ boolean expression over a FaceMarker called marker. Typically solver.grid_selector.createFaceGuard().
relative_time_step_size	float The \( c_k \) of the Runge-Kutta stage, i.e. the stage's time stamp relative to the time step size, exahype2.api.rungekutta.ButcherTableau.ButcherTableau.relative_time_step_sizes().

Reimplemented from peano4.api.solversteps.ActionSet.ActionSet.

Definition at line 96 of file ApplyDirichletBoundaryConditions.py.

References exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.__init__().

Referenced by exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.__init__().

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Member Function Documentation

◆ add_task_to_time_step()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.add_task_to_time_step	(	solver,
		exahype2_project,
		time_step,
		reconstruction_task,
		name_suffix = `""`,
		relative_time_step_size = `0.0`,
		additional_guard = `"true"`
	)

static

Add the boundary task in front of the reconstruction of the halo.

If all axes of the domain are periodic, or if the solver uses exahype2.api.SommerfeldBoundaryConditions (which replace the roll over instead), the routine does nothing. Otherwise, it adds a FACE task which sets the ghost grid cells of solver._patch_overlap_current_time_step, and makes reconstruction_task depend on it.

Parameters

solver	exahype2.api.Solver The solver. Its boundary condition terms have to be consistent with the domain, exahype2.api.blockstructured.BoundaryConditions.get_boundary_conditions().
exahype2_project	exahype2.api.Project Provides the periodic boundary conditions.
time_step	peano4.api.taskgraph.Graph The time step's task graph.
reconstruction_task	peano4.api.taskgraph.Task The task reading solver._patch_overlap_current_time_step to reconstruct the patches' halos.
name_suffix	str Appended to the task's name. A time step with several Runge-Kutta stages adds one boundary task per stage, and the names of the tasks have to differ.
relative_time_step_size	float The \( c_k \) of the Runge-Kutta stage, see the constructor.
additional_guard	str C++ predicate which is combined with the guard of the boundary action set, e.g. the is<Name>Active() of a plotter which reconstructs the halo (exahype2.api.rkfd4.WriteCheckpoint).

Returns: peano4.api.taskgraph.Task or None The boundary task, or None if no Dirichlet task is required.

Definition at line 162 of file ApplyDirichletBoundaryConditions.py.

◆ get_action_set_name()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.get_action_set_name ( self )

Return unique action set name.

Returns a description (word) for the mapping which is also used as class name for the generated type. As a consequence, the result should be one word (if possible) and uppercase. Also, every subclass should overwrite this routine.

The generator will take the result and construct eventually classes similar to MyStep2Dummy.h and MyStep2Dummy.cpp or similar for the example below, where we return Dummy.

Reimplemented from peano4.api.solversteps.ActionSet.ActionSet.

Definition at line 146 of file ApplyDirichletBoundaryConditions.py.

◆ get_body_of_operation()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.get_body_of_operation	(	self,
		operation_name
	)

Return actual C++ code snippets to be inserted into C++ code.

See class' string constants starting with OPERATION_ for possible values of operation_name. The snippet is executed if and only if the guard returned by get_guard_of_operation() holds, i.e. the body should not evaluate the guard itself. See the section "Guard and body" in the class documentation.

Reimplemented from peano4.api.solversteps.ActionSet.ActionSet.

Definition at line 130 of file ApplyDirichletBoundaryConditions.py.

Referenced by peano4.api.solversteps.ActionSet.ActionSet.get_implementation_of_operation().

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◆ get_guard_of_operation()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.get_guard_of_operation	(	self,
		operation_name
	)

Return the guard of an operation.

The guard is a C++ boolean expression. The body of the operation (see get_body_of_operation()) is executed if and only if the guard holds. The guard can use the same arguments as the body, i.e. the marker and the fine and coarse grid data. By default, the guard is true, i.e. the body is always executed.

See class' string constants starting with OPERATION_ for possible values of operation_name.

Reimplemented from peano4.api.solversteps.ActionSet.ActionSet.

Definition at line 138 of file ApplyDirichletBoundaryConditions.py.

Referenced by peano4.api.solversteps.ActionSet.ActionSet.get_implementation_of_operation().

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◆ get_includes()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.get_includes ( self )

Return include statements that you need.

All of these includes will eventually end up in the header of the generated C++ code.

Reimplemented from peano4.api.solversteps.ActionSet.ActionSet.

Definition at line 152 of file ApplyDirichletBoundaryConditions.py.

◆ user_should_modify_template()

exahype2.api.rkfd4.actionsets.ApplyDirichletBoundaryConditions.ApplyDirichletBoundaryConditions.user_should_modify_template ( self )

Is the user allowed to modify the output.

Return whether you expect the user to modify the generated code. If this is the case, then the API places the generated output in the directory actions. Otherwise, it goes into the observer directory and will be overwritten in each and every Python run.

Reimplemented from peano4.api.solversteps.ActionSet.ActionSet.

Definition at line 149 of file ApplyDirichletBoundaryConditions.py.