CellCenteredFiniteDifferences.py

Go to the documentation of this file.

# This file is part of the ExaHyPE2 project. For conditions of distribution and
# use, please see the copyright notice at www.peano-framework.org
import os
 
import peano4
import peano4.datamodel
import peano4.output.TemplatedHeaderFile
import peano4.output.TemplatedHeaderImplementationFilePair
import peano4.output.Jinja2TemplatedHeaderFile
import peano4.output.Jinja2TemplatedHeaderImplementationFilePair
 
import jinja2
 
from abc import abstractmethod
from enum import Enum
 
import exahype2
import exahype2.solvers.rkfd.actionsets
 
from exahype2.solvers.PDETerms import PDETerms
 
from exahype2.solvers.ButcherTableau import RungeKutta_steps
from exahype2.solvers.Storage import Storage
 
 
 
class CellCenteredFiniteDifferences(object):
    """
    Abstract solver for patch-based finite diffences
 
    All solvers in ExaHyPE are cell-centered discretisations.
 
 
    ## Adaptive mesh refinement
 
    We have, at the moment, no hard-coded AMR operator set available unless
    you work with an overlap of one. In this case, you find operators in the
    toolbox. Very few pre-manufactured operators there are ready to go for
    higher overlaps (the injection operator is an example). In general, you
    will have to inject your own transfer operators.
 
    It depends on the flavour that you want to use for your interpolation and
    restriction. A simple interpolation for an overlap of three and a patch_size
    of five would be
 
            self._interpolation = "tensor_product< " + self._name + ">"
            self.add_solver_constants(   "static constexpr double  NormalInterpolationMatrix1d[]     = {0.0, 1.0, 0.0};" )
            self.add_solver_constants( " ""static constexpr double  TangentialInterpolationMatrix1d[] = {
                    1.0,0.0,0.0,0.0,0.0,
                    1.0,0.0,0.0,0.0,0.0,
                    1.0,0.0,0.0,0.0,0.0,
                    0.0,1.0,0.0,0.0,0.0,
                    0.0,1.0,0.0,0.0,0.0,
 
                    0.0,1.0,0.0,0.0,0.0,
                    0.0,0.0,1.0,0.0,0.0,
                    0.0,0.0,1.0,0.0,0.0,
                    0.0,0.0,1.0,0.0,0.0,
                    0.0,0.0,0.0,1.0,0.0,
 
                    0.0,0.0,0.0,1.0,0.0,
                    0.0,0.0,0.0,1.0,0.0,
                    0.0,0.0,0.0,0.0,1.0,
                    0.0,0.0,0.0,0.0,1.0,
                    0.0,0.0,0.0,0.0,1.0
            };" "" )
    """
    def __init__(
        self,
        name,
        patch_size,
        overlap,
        rk_order,
        unknowns,
        auxiliary_variables,
        min_meshcell_h,
        max_meshcell_h,
        plot_grid_properties,
        kernel_namespace,
        baseline_action_set_descend_invocation_order=0,
    ):
        """
        name: string
           A unique name for the solver. This one will be used for all generated
           classes. Also the C++ object instance later on will incorporate this
           name.
 
        patch_size: int
           Size of the patch in one dimension. All stuff here's dimension-generic.
 
        overlap: int
           That's the size of the halo layer which is half of the overlap with a
           neighbour. A value of 1 means that a patch_size x patch_size patch in
           2d is surrounded by one additional cell layer. The overlap has to be
           bigger or equal to one. It has to be smaller or equal to patch_size.
 
        unknowns: int
           Number of unknowns per Finite Volume voxel.
 
        auxiliary_variables: int
           Number of auxiliary variables per Finite Volume voxel. Eventually, both
           unknowns and auxiliary_variables are merged into one big vector if we
           work with AoS. But the solver has to be able to distinguish them, as
           only the unknowns are subject to a hyperbolic formulation.
 
        min_meshcell_h: double
           This size refers to the individual Finite Volume.
 
        max_meshcell_h: double
           This size refers to the individual Finite Volume.
 
        plot_grid_properties: Boolean
           Clarifies whether a dump of the data should be enriched with grid info
           (such as enclave status flags), too.
        """
        self._name = name
 
        self._min_meshcell_h = min_meshcell_h
        self._max_meshcell_h = max_meshcell_h
        self._plot_grid_properties = plot_grid_properties
 
        self._patch_size = patch_size
        self._overlap = overlap
        self._rk_order = rk_order
 
        """
        self._unknowns and self._auxiliary_variables respectively hold the number of unknowns and 
        auxiliary variables in the equation to be computed. Unknowns are variables that change over
        time whereas auxiliary variables can be space-dependent but don't vary over time.
        These can be specified either as simple ints or by a dictionary
        (e.g.) unknowns = {'a': 1, 'b': 1, 'c': 3}
        in which the user specifies the multiplicity of the variable (the velocity has one component
        per dimension for example.)
        If they are specified by a dictionary then the code generates a "VariableShortcuts" file which
        allows the user to specifiy a variable by name and automatically maps this to the right position
        in an array for better legibility. Otherwise they must manually remember the position of each
        variable manually.
 
        use_var_shortcut is used to know whether or not the user passed their variables via a dict
        variable_names and variable_pos are used internally to remember the names and respective
        positions of variables if set by a dictionary.
        """
        self._use_var_shortcut = False
        self._variable_names = []
        self._variable_pos = [0]
 
        if type(unknowns) is dict:
            self._unknowns = sum(unknowns.values())
            self._variable_names += list(unknowns.keys())
            for var in list(unknowns.values()):
                self._variable_pos.append(var + self._variable_pos[-1])
            self._use_var_shortcut = True
        elif type(unknowns) is int:
            self._unknowns = unknowns
        else:
            raise Exception(
                "not a valid type for parameter unknowns, needs to be int or dictionary"
            )
 
        if type(auxiliary_variables) is dict:
            self._auxiliary_variables = sum(auxiliary_variables.values())
            self._variable_names += list(auxiliary_variables.keys())
            for var in list(auxiliary_variables.values()):
                self._variable_pos.append(var + self._variable_pos[-1])
            self._use_var_shortcut = True
        elif type(auxiliary_variables) is int:
            self._auxiliary_variables = auxiliary_variables
        else:
            raise Exception(
                "not a valid type for parameter auxiliary_variables, needs to be int or dictionary"
            )
 
        self._solver_constants = ""
        self._user_action_set_includes = ""
        self._user_solver_includes = ""
 
        self._kernel_namespace = kernel_namespace
 
        if min_meshcell_h > max_meshcell_h:
            print(
                "Error: min_meshcell_h ("
                + str(min_meshcell_h)
                + ") is bigger than max_meshcell_h ("
                + str(max_meshcell_h)
                + ")"
            )
 
        self._reconstructed_array_memory_location = (
            peano4.toolbox.blockstructured.ReconstructedArrayMemoryLocation.CallStack
        )
 
        self._solver_template_file_class_name = None
 
        self._plot_description = ""
 
        self.select_dofs_to_print = None
 
        self._action_set_initial_conditions = None
        self._action_set_initial_conditions_for_grid_construction = None
        self._action_set_AMR = None
        self._action_set_AMR_commit_without_further_analysis = None
        self._action_set_handle_boundary = None
        self._action_set_project_patch_onto_faces = None
        self._action_set_roll_over_update_of_faces = None
        self._action_set_copy_new_faces_onto_old_faces = None
        self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement = (
            None
        )
        self._action_set_postprocess_solution = None
        self._action_set_preprocess_solution = None
 
        self._compute_time_step_size = "#error Not yet defined"
        self._compute_new_time_step_size = "#error Not yet defined"
        self._preprocess_reconstructed_patch = ""
        self._postprocess_updated_patch = ""
 
        self._compute_kernel_call = "#error Not yet defined"
 
        self._reconstruction_kernel_call = "#error Not yet defined"
        self._primary_variables_indices = "#error Not yet defined"
        self._auxiliary_variables_indices = "#error Not yet defined"
 
        self._compute_eigenvalue = False
        self._abstract_solver_user_declarations = ""
        self._abstract_solver_user_definitions = ""
        self._solver_user_declarations = ""
        self._solver_user_definitions = ""
 
        self._start_time_step_implementation = ""
        self._finish_time_step_implementation = ""
        self._constructor_implementation = ""
 
        self._boundary_conditions_implementation = None
        self._refinement_criterion_implementation = None
        self._initial_conditions_implementation = None
 
        self._interpolation = "#error Not yet defined"
        self._restriction = "#error Not yet defined"
 
        self._baseline_action_set_descend_invocation_order = baseline_action_set_descend_invocation_order
 
        self.switch_storage_scheme(Storage.SmartPointers, Storage.SmartPointers)
        
 
    def __str__(self):
        result = (
            """
Name:                   """
            + self._name
            + """
Type:                   """
            + self.__class__.__name__
            + """
Patch size:             """
            + str(self._patch_size)
            + """  
Runge-Kutta order:      """
            + str(self._rk_order)
            + """
Overlap:                """
            + str(self._overlap)
            + """  
Unknowns:               """
            + str(self._unknowns)
            + """
Auxiliary variables:    """
            + str(self._auxiliary_variables)
            + """
h_meshcell_min:           """
            + str(self._min_meshcell_h)
            + """
h_meshcell_max:           """
            + str(self._max_meshcell_h)
            + """
"""
        )
        return result
 
    __repr__ = __str__
 
    def get_min_number_of_spacetree_levels(self, domain_size):
        coarsest_tree_level = 0
        while (
            domain_size * 3 ** (-coarsest_tree_level) / self._patch_size
            > self._max_meshcell_h
        ):
            coarsest_tree_level += 1
        return coarsest_tree_level
 
    def get_max_number_of_spacetree_levels(self, domain_size):
        finest_tree_level = 0
        while (
            domain_size * 3 ** (-finest_tree_level) / self._patch_size
            > self._min_meshcell_h
        ):
            finest_tree_level += 1
        return finest_tree_level
 
    #    self._overlap              = overlap
    #    self._unknowns             = unknowns
    #    self._auxiliary_variables  = auxiliary_variables
 
    def get_coarsest_number_of_patches(self, domain_size):
        return 3 ** self.get_min_number_of_spacetree_levels(domain_size)
 
    def get_finest_number_of_patches(self, domain_size):
        return 3 ** self.get_max_number_of_spacetree_levels(domain_size)
 
    def get_coarsest_number_of_compute_grid_cells(self, domain_size):
        return self.get_coarsest_number_of_patches(domain_size) * self._patch_size
 
    def get_finest_number_of_compute_grid_cells(self, domain_size):
        return self.get_finest_number_of_patches(domain_size) * self._patch_size
 
    def get_coarsest_compute_grid_cell_size(self, domain_size):
        return domain_size / self.get_coarsest_number_of_compute_grid_cells(domain_size)
 
    def get_finest_compute_grid_cell_size(self, domain_size):
        return domain_size / self.get_finest_number_of_compute_grid_cells(domain_size)
 
    def create_readme_descriptor(self, domain_offset, domain_size):
        return (
            """
### ExaHyPE 2 solver
 
"""
            + str(self)
            + """
 
Real type of this solver: """
            + str(type(self))
            + """
 
We assume that you use a domain size of (0,"""
            + str(domain_size)
            + """)^d. Peano 4 will cut this domain equidistantly 
and recursively into three parts along each coordinate axis. This yields a spacetree.
 
The spacetree will at least have """
            + str(self.get_min_number_of_spacetree_levels(domain_size))
            + """ levels.
The spacetree will at most have """
            + str(self.get_max_number_of_spacetree_levels(domain_size))
            + """ levels.
 
The spacetree will thus span at least """
            + str(self.get_coarsest_number_of_patches(domain_size))
            + """ octants/cells (see clarification below) per coordinate axis. This means a """
            + str(self.get_coarsest_number_of_patches(domain_size))
            + """^d grid of octants.
The spacetree will thus span at most """
            + str(self.get_finest_number_of_patches(domain_size))
            + """ octants/cells (see clarification below) per coordinate axis. This means a """
            + str(self.get_finest_number_of_patches(domain_size))
            + """^d grid of octants.
 
ExaHyPE 2 embeds """
            + str(self._patch_size)
            + """^d patches of compute cells into the finest tree level. 
In the text above, we refer to the elements of this level of the tree as octants.
The octants are squares/cubes and many papers refer to them as cells, but they are not 
the actual compute data structure. The compute data structure is the cells that
are embedded into these finest level spacetree cells. We therefore prefer the 
term octant for the latter, whereas we use the term (compute) cell for the 
entities that are actually used for the computations, i.e. hold degrees of 
freedom, and are actually visible within Paraview, e.g.
 
The coarsest possible mesh will consist of """
            + str(self.get_coarsest_number_of_compute_grid_cells(domain_size))
            + """ compute cells per coordinate axis.
The finest possible mesh will consist of """
            + str(self.get_finest_number_of_compute_grid_cells(domain_size))
            + """ compute cells per coordinate axis.
 
The coarsest mesh width of """
            + str(self.get_coarsest_compute_grid_cell_size(domain_size))
            + """ is thus just smaller than the maximum mesh size """
            + str(self._max_meshcell_h)
            + """.
The finest mesh width of """
            + str(self.get_finest_compute_grid_cell_size(domain_size))
            + """ is thus just smaller than the minimum mesh size """
            + str(self._min_meshcell_h)
            + """.
 
"""
        )
 
    @property
    def user_action_set_includes(self):
        """
 
        Add further includes to this property, if your action sets require some additional
        routines from other header files.
 
        """
        return self._user_action_set_includes
 
    @property
    def user_solver_includes(self):
        """
 
        Add further includes to this property, if your solver requires some additional
        routines from other header files.
 
        """
        return self._user_solver_includes
 
    def number_of_Runge_Kutta_steps(self):
        """!
        
        Return number of steps required to realise the Runge-Kutta scheme
        
        Delegate to ButcherTableau.RungeKutta_steps, which tells us for a given
        polynomial order _rk_order how many Runge Kutta steps we have to 
        employ.
        
        """
        return RungeKutta_steps(self._rk_order)
 
    def add_user_action_set_includes(self, value):
        """
 
        Add further includes to this property, if your action sets require some additional
        routines from other header files.
 
        """
        self._user_action_set_includes += value
 
    def add_user_solver_includes(self, value):
        """
 
        Add further includes to this property, if your solver requires some additional
        routines from other header files.
 
        """
        self._user_solver_includes += value
 
    @abstractmethod
    def create_data_structures(self):
        """
 
        Recall in subclasses if you wanna change the number of unknowns
        or auxiliary variables. See class description's subsection on
        data flow.
 
        :: Call order and ownership
 
        This operation can be called multiple times. However, only the very
        last call matters. All previous calls are wiped out.
 
        If you have a hierarchy of solvers, every create_data_structure()
        should first(!) call its parent version. This way, you always ensure
        that all data are in place before you continue to alter the more
        specialised versions. So it is (logically) a top-down (general to
        specialised) run through all create_data_structure() variants
        within the inheritance tree.
 
 
        :: Arguments
 
        _patch: Patch (NxNxN)
          Actual patch data. We use Finite Volumes, so this is
          always the current snapshot, i.e. the valid data at one point.
 
        _patch_overlap_old, _patch_overlap_new: Patch (2xNxN)
          This is a copy/excerpt from the two adjacent finite volume
          snapshots plus the old data as backup. If I want to implement
          local timestepping, I don't have to backup the whole patch
          (see _patch), but I need a backup of the face data to be able
          to interpolate in time.
 
        _patch_overlap_update: Patch (2xNxN)
          This is hte new update. After the time step, I roll this
          information over into _patch_overlap_new, while I backup the
          previous _patch_overlap_new into _patch_overlap_old. If I
          worked with regular meshes only, I would not need this update
          field and could work directly with _patch_overlap_new. However,
          AMR requires me to accumulate data within new while I need
          the new and old data temporarily. Therefore, I employ this
          accumulation/roll-over data which usually is not stored
          persistently.
 
        """
        self._patch = peano4.datamodel.Patch(
            (self._patch_size, self._patch_size, self._patch_size),
            self._unknowns + self._auxiliary_variables,
            self._unknown_identifier(),
        )
        self._patch_estimates = peano4.datamodel.Patch(
            (
                self.number_of_Runge_Kutta_steps() * self._patch_size,
                self._patch_size,
                self._patch_size,
            ),
            self._unknowns,
            self._unknown_identifier() + "RhsEstimates",
        )
        self._patch_overlap_old = peano4.datamodel.Patch(
            (2 * self._overlap, self._patch_size, self._patch_size),
            self._unknowns + self._auxiliary_variables,
            self._unknown_identifier() + "Old",
        )
        self._patch_overlap_new = peano4.datamodel.Patch(
            (2 * self._overlap, self._patch_size, self._patch_size),
            self._unknowns + self._auxiliary_variables,
            self._unknown_identifier() + "New",
        )
        self._patch_overlap_update = peano4.datamodel.Patch(
            (2 * self._overlap, self._patch_size, self._patch_size),
            self._unknowns + self._auxiliary_variables,
            self._unknown_identifier() + "Update",
        )
 
        if self._cell_data_storage == Storage.CallStack:
            self._patch.generator = peano4.datamodel.PatchToDoubleArray(
                self._patch, "double"
            )
            self._patch_estimates.generator = peano4.datamodel.PatchToDoubleArray(
                self._patch_estimates, "double"
            )
        elif self._cell_data_storage == Storage.Heap:
            self._patch.generator = peano4.datamodel.PatchToDoubleArrayOnHeap(
                self._patch, "double"
            )
            self._patch_estimates.generator = peano4.datamodel.PatchToDoubleArrayOnHeap(
                self._patch_estimates, "double"
            )
        elif self._cell_data_storage == Storage.SmartPointers:
            self._patch.generator = peano4.datamodel.PatchToDoubleArrayWithSmartPointer(
                self._patch, "double"
            )
            self._patch_estimates.generator = (
                peano4.datamodel.PatchToDoubleArrayWithSmartPointer(
                    self._patch_estimates, "double"
                )
            )
 
        if self._face_data_storage == Storage.CallStack:
            self._patch_overlap_old.generator = peano4.datamodel.PatchToDoubleArray(
                self._patch_overlap_old, "double"
            )
            self._patch_overlap_new.generator = peano4.datamodel.PatchToDoubleArray(
                self._patch_overlap_new, "double"
            )
            self._patch_overlap_update.generator = peano4.datamodel.PatchToDoubleArray(
                self._patch_overlap_update, "double"
            )
        elif self._face_data_storage == Storage.Heap:
            self._patch_overlap_old.generator = (
                peano4.datamodel.PatchToDoubleArrayOnHeap(
                    self._patch_overlap_old, "double"
                )
            )
            self._patch_overlap_new.generator = (
                peano4.datamodel.PatchToDoubleArrayOnHeap(
                    self._patch_overlap_new, "double"
                )
            )
            self._patch_overlap_update.generator = (
                peano4.datamodel.PatchToDoubleArrayOnHeap(
                    self._patch_overlap_update, "double"
                )
            )
        elif self._face_data_storage == Storage.SmartPointers:
            self._patch_overlap_old.generator = (
                peano4.datamodel.PatchToDoubleArrayWithSmartPointer(
                    self._patch_overlap_old, "double"
                )
            )
            self._patch_overlap_new.generator = (
                peano4.datamodel.PatchToDoubleArrayWithSmartPointer(
                    self._patch_overlap_new, "double"
                )
            )
            self._patch_overlap_update.generator = (
                peano4.datamodel.PatchToDoubleArrayWithSmartPointer(
                    self._patch_overlap_update, "double"
                )
            )
        else:
            assert False, "storage variant {} not supported".format(
                self._face_data_storage
            )
 
        self._patch_overlap_old.generator.merge_method_definition = (
            peano4.toolbox.blockstructured.get_face_merge_implementation(
                self._patch_overlap_old
            )
        )
        self._patch_overlap_new.generator.merge_method_definition = (
            peano4.toolbox.blockstructured.get_face_merge_implementation(
                self._patch_overlap_new
            )
        )
        self._patch.generator.merge_method_definition = (
            peano4.toolbox.blockstructured.get_cell_merge_implementation(self._patch)
        )
 
        self._patch_overlap_old.generator.includes += """
#include "peano4/utils/Loop.h"
#include "repositories/SolverRepository.h" 
"""
        self._patch_overlap_new.generator.includes += """
#include "peano4/utils/Loop.h"
#include "repositories/SolverRepository.h" 
"""
 
        self._patch.generator.load_store_compute_flag = "::peano4::grid::constructLoadStoreComputeFlag({},{},{})".format(
            self._provide_cell_data_to_compute_kernels_default_guard(),
            self._load_cell_data_default_guard(),
            self._store_cell_data_default_guard(),
        )
 
        self._patch_estimates.generator.load_store_compute_flag = "::peano4::grid::constructLoadStoreComputeFlag({},{},{})".format(
            self._provide_cell_data_to_compute_kernels_default_guard(),
            self._load_cell_data_default_guard(),
            self._store_cell_data_default_guard(),
        )
 
        self._patch_overlap_old.generator.send_condition = "false"
        self._patch_overlap_old.generator.receive_and_merge_condition = "false"
 
        self._patch_overlap_new.generator.send_condition = "false"
        self._patch_overlap_new.generator.receive_and_merge_condition = "false"
 
        self._patch_overlap_update.generator.send_condition = "false"
        self._patch_overlap_update.generator.receive_and_merge_condition = "false"
 
        self._patch_overlap_old.generator.load_store_compute_flag = "::peano4::grid::constructLoadStoreComputeFlag({},{},{})".format(
          self._provide_face_data_to_compute_kernels_default_guard(),
          self._load_face_data_default_guard(),
          self._store_face_data_default_guard(),
        )
 
        self._patch_overlap_new.generator.load_store_compute_flag = "::peano4::grid::constructLoadStoreComputeFlag({},{},{})".format(
          self._provide_face_data_to_compute_kernels_default_guard(),
          self._load_face_data_default_guard(),
          self._store_face_data_default_guard(),
        )
 
        self._patch_overlap_update.generator.load_store_compute_flag = "::peano4::grid::constructLoadStoreComputeFlag({},{},{})".format(
          self._provide_face_data_to_compute_kernels_default_guard(),
          "false",
          "false"
        )
 
        self._patch.generator.includes += """
#include "../repositories/SolverRepository.h"
"""
        self._patch_estimates.generator.includes += """
#include "../repositories/SolverRepository.h"
"""
        self._patch_overlap_old.generator.includes += """
#include "../repositories/SolverRepository.h"
"""
        self._patch_overlap_new.generator.includes += """
#include "../repositories/SolverRepository.h"
"""
        self._patch_overlap_update.generator.includes += """
#include "../repositories/SolverRepository.h"
"""
 
        self._cell_label = exahype2.grid.create_cell_label(self._name)
        self._face_label = exahype2.grid.create_face_label(self._name)
 
    @abstractmethod
    def create_action_sets(self):
        """!
 
        Create required action sets
 
        Overwrite in subclasses if you wanna create different
        action sets.
 
        ## Call order and ownership
 
        This operation can be called multiple times. However, only the very
        last call matters. All previous calls are wiped out.
 
        If you have a hierarchy of solvers, every create_data_structure()
        should first(!) call its parent version. This way, you always ensure
        that all data are in place before you continue to alter the more
        specialised versions. So it is (logically) a top-down (general to
        specialised) run through all create_data_structure() variants
        within the inheritance tree.
 
        :: Recreation vs backup (state discussion)
 
        We faced some issues with action sets that should not be
        overwritten. For example, the postprocessing should not be overwritten
        as users might want to set it and then later on reset the number of
        unknowns, e.g. In this case, you would loose your postprocessing if
        create_action_sets() recreated them. So I decided to make an exception
        here: the postprocessing step is never overwritten by the standard
        classes.
 
        There are further action sets which have a state, which users might
        want to alter. The most prominent one is the AMR routines, where users
        often alter the interpolation and restriction scheme. Here, things are
        tricky: If we keep the default one, the action set would not pick up
        if you changed the number of unknowns, e.g. However, if we recreated
        the action set, we'd miss out on any changed interpolation/restriction
        scheme. Therefore, I have to hold the interpolation and restriction
        scheme seperatae.
 
        ## Injecting your own guards
 
        If you inject your own guards, you should combine them with a storage
        predicate, i.e. _store_cell_data_default_guard() and
        _load_cell_data_default_guard(). The action sets themselves will not
        combine the guard with further boolean expressions. Also, you have to
        study carefully if a predicate accepts a unique guard or a set of
        guards.
 
 
        ## Priorities
 
        All action sets are given the right (default) priorities in this step.
        You can alter them in subclasses, but it might be more appropriate to
        set the priorities of your own action sets relative to the existing
        ones using self._baseline_action_set_descend_invocation_order.
 
        """
        self._action_set_initial_conditions = (
            exahype2.solvers.rkfd.actionsets.InitialCondition(
                self, self._store_cell_data_default_guard(), "true"
            )
        )
        self._action_set_initial_conditions_for_grid_construction = (
            exahype2.solvers.rkfd.actionsets.InitialCondition(
                self, self._store_cell_data_default_guard(), "false"
            )
        )
        self._action_set_AMR = exahype2.solvers.rkfd.actionsets.AdaptivityCriterion(
            solver=self,
            guard=self._store_cell_data_default_guard(),
            build_up_new_refinement_instructions=True,
            implement_previous_refinement_instructions=True,
            called_by_grid_construction=False,
        )
        self._action_set_AMR_commit_without_further_analysis = (
            exahype2.solvers.rkfd.actionsets.AdaptivityCriterion(
                solver=self,
                guard=self._store_cell_data_default_guard(),
                build_up_new_refinement_instructions=False,
                implement_previous_refinement_instructions=True,
                called_by_grid_construction=False,
            )
        )
        self._action_set_AMR_throughout_grid_construction = (
            exahype2.solvers.rkfd.actionsets.AdaptivityCriterion(
                solver=self,
                guard=self._store_cell_data_default_guard(),
                build_up_new_refinement_instructions=True,
                implement_previous_refinement_instructions=True,
                called_by_grid_construction=True,
            )
        )
        self._action_set_handle_boundary = (
            exahype2.solvers.rkfd.actionsets.HandleBoundary(
                self, self._store_face_data_default_guard()
            )
        )
        self._action_set_project_patch_onto_faces = (
            exahype2.solvers.rkfd.actionsets.ProjectPatchOntoFaces(self)
        )
        self._action_set_roll_over_update_of_faces = (
            exahype2.solvers.rkfd.actionsets.RollOverUpdatedFace(
                self, self._store_face_data_default_guard()
            )
        )
        self._action_set_copy_new_faces_onto_old_faces = (
            peano4.toolbox.blockstructured.BackupPatchOverlap(
                self._patch_overlap_new,
                self._patch_overlap_old,
                False,
                self._store_face_data_default_guard(),
                self._get_default_includes(),
            )
        )
        self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement = exahype2.solvers.rkfd.actionsets.DynamicAMR(
            solver=self,
            interpolation=self._interpolation,
            restriction=self._restriction,
        )
 
        self._action_set_compute_final_linear_combination = (
            exahype2.solvers.rkfd.actionsets.ComputeFinalLinearCombination(
                solver=self, guard=self._store_cell_data_default_guard()
            )
        )
 
        # This one is different: it is the hook-in point for other solvers, so we create it
        # only once if it does not exist
        if self._action_set_postprocess_solution == None:
            self._action_set_postprocess_solution = (
                exahype2.solvers.rkfd.actionsets.EmptyPostprocessSolution(self)
            )
        if self._action_set_preprocess_solution == None:
            self._action_set_preprocess_solution = (
                exahype2.solvers.rkfd.actionsets.EmptyPreprocessSolution(self)
            )
 
        self._action_set_update_face_label = exahype2.grid.UpdateFaceLabel(self._name)
        self._action_set_update_cell_label = exahype2.grid.UpdateCellLabel(self._name)
 
        self._action_set_initial_conditions.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 1
        )
        self._action_set_initial_conditions_for_grid_construction.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 1
        )
        self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order
        )
        self._action_set_copy_new_faces_onto_old_faces.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order
        )
        self._action_set_roll_over_update_of_faces.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 1
        )
        self._action_set_update_face_label.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 2
        )
        self._action_set_update_cell_label.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 2
        )
        self._action_set_handle_boundary.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 3
        )
        self._action_set_compute_final_linear_combination.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 5
        )
        self._action_set_project_patch_onto_faces.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order + 6
        )
        self._action_set_AMR.descend_invocation_order = self._baseline_action_set_descend_invocation_order + 6
        self._action_set_postprocess_solution.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order
        )  # will be in touch last
        self._action_set_preprocess_solution.descend_invocation_order = (
            self._baseline_action_set_descend_invocation_order
        )
 
        self._action_set_update_cell = None
 
 
    def _provide_cell_data_to_compute_kernels_default_guard(self):
       return (
                        "not marker.willBeRefined() "
                        + "and repositories::"
                        + self.get_name_of_global_instance()
                        + ".getSolverState()!="
                        + self._name
                        + "::SolverState::GridConstruction"
                )
 
    def _provide_face_data_to_compute_kernels_default_guard(self):
        return (
                        "not marker.willBeRefined() "
                        + "and repositories::"
                        + self.get_name_of_global_instance()
                        + ".getSolverState()!="
                        + self._name
                        + "::SolverState::GridConstruction"
                )
                
    def _store_cell_data_default_guard(self):
        """!
 
        Extend the guard via ands only. Never use an or, as subclasses might
        extend it as well, and they will append further ends.
 
        """
        return (
            "not marker.willBeRefined() "
            + "and repositories::"
            + self.get_name_of_global_instance()
            + ".getSolverState()!="
            + self._name
            + "::SolverState::GridConstruction"
        )
 
    def _load_cell_data_default_guard(self):
        """!
 
        Extend the guard via ands only. Never use an or, as subclasses might
        extend it as well, and they will append further ends.
 
        """
        return (
            "not marker.hasBeenRefined() "
            + "and repositories::"
            + self.get_name_of_global_instance()
            + ".getSolverState()!="
            + self._name
            + "::SolverState::GridConstruction "
            + "and repositories::"
            + self.get_name_of_global_instance()
            + ".getSolverState()!="
            + self._name
            + "::SolverState::GridInitialisation"
        )
 
    def _store_face_data_default_guard(self):
        """!
 
        Extend the guard via ands only. Never use an or, as subclasses might
        extend it as well, and they will append further ends.
 
        """
        return (
            "not marker.willBeRefined() "
            + "and repositories::"
            + self.get_name_of_global_instance()
            + ".getSolverState()!="
            + self._name
            + "::SolverState::GridConstruction"
        )
 
    def _load_face_data_default_guard(self):
        """!
 
        Extend the guard via ands only. Never use an or, as subclasses might
        extend it as well, and they will append further ends.
 
        """
        return (
            "not marker.hasBeenRefined() "
            + "and repositories::"
            + self.get_name_of_global_instance()
            + ".getSolverState()!="
            + self._name
            + "::SolverState::GridConstruction "
            + "and repositories::"
            + self.get_name_of_global_instance()
            + ".getSolverState()!="
            + self._name
            + "::SolverState::GridInitialisation"
        )
 
    def _unknown_identifier(self):
        return self._name + "Q"
 
    def get_name_of_global_instance(self):
        return "instanceOf" + self._name
 
    def add_to_Peano4_datamodel(self, datamodel, verbose):
        """!
 
        Add all required data to the Peano4 project's datamodel
        so it is properly built up
 
        """
        if verbose:
            print("Patch data")
            print("----------")
            print(str(self._patch))
            print("Patch overlap data")
            print("----------")
            print(str(self._patch_overlap_old))
            print("Patch overlap data")
            print("----------")
            print(str(self._patch_overlap_new))
        datamodel.add_cell(self._cell_label)
        datamodel.add_cell(self._patch)
        datamodel.add_cell(self._patch_estimates)
        datamodel.add_face(self._patch_overlap_old)
        datamodel.add_face(self._patch_overlap_new)
        datamodel.add_face(self._patch_overlap_update)
        datamodel.add_face(self._face_label)
 
    def add_use_data_statements_to_Peano4_solver_step(self, step):
        """
        Tell Peano what data to move around
 
        Inform Peano4 step which data are to be moved around via the
        use_cell and use_face commands. This operation is generic from
        ExaHyPE's point of view, i.e. I use it for all grid sweep types.
 
        """
        step.use_cell(self._patch)
        step.use_cell(self._patch_estimates)
        step.use_cell(self._cell_label)
        step.use_face(self._patch_overlap_old)
        step.use_face(self._patch_overlap_new)
        step.use_face(self._patch_overlap_update)
        step.use_face(self._face_label)
 
    def _get_default_includes(self):
        return """
#include "tarch/la/Vector.h" 
 
#include "peano4/utils/Globals.h"
#include "peano4/utils/Loop.h"
 
#include "repositories/SolverRepository.h"
"""
 
    def add_actions_to_init_grid(self, step, restart_from_checkpoint=False):
        """!
 
        Add your actions to init grid
 
        The AMR stuff has to be the very first thing. Actually, the AMR routines'
        interpolation doesn't play any role here. But the restriction indeed is
        very important, as we have to get the face data for BCs et al. The action
        set order is inverted while we ascend within the tree again. Therefore, we
        add the AMR action set first which means it will be called last when we go
        from fine to coarse levels within the tree.
 
        The projection onto the faces is a postprocessing step. This is different
        to DG, where we need face data for the current time step's solution. Here,
        we ensure that all halos are valid for the subsequent time step again.
 
        ## Ordering
 
        The order of the action sets is preserved throughout the steps down within
        the tree hierarchy. It is inverted throughout the backrolling.
 
        This is what we want to achieve:
 
        - Project solution onto faces. This happens in touchCellLastTime(). See
          exahype2.solvers.rkfd.actionsets.ProjectPatchOntoFaces for comments.
          The project will end up in QUpdate.
        - Roll updates over on the faces from QUpdate into Q_new. This is done
          by RollOverUpdateFace, which requires in turn that the getUpdated()
          flag is set. As the roll-over plugs into touchFaceLastTime(), it will
          always be called after the projection, since the latter is a cell
          operation.
        - Copy new face data Q_new into old face data Q_old, as this is the
          initial sweep, i.e. the old face data otherwise might hold rubbish.
          This is a backup operation realised through the action set
          BackupPatchOverlap. This one plugs into touchFaceLastTime() too.
          Therefore, it is important that its priority is smaller than the one
          of the roll-over, since we invert the call order for the touch-last
          events.
        - Restrict the data to the coarser level if we are on a hanging face.
 
 
        """
        assert (
            self._action_set_copy_new_faces_onto_old_faces.descend_invocation_order
            < self._action_set_roll_over_update_of_faces.descend_invocation_order
        )
 
        if restart_from_checkpoint:
            self._action_set_initial_conditions = (
                exahype2.solvers.rkfd.actionsets.InitialCondition(
                    self, self._store_cell_data_default_guard(), "true", restart_from_checkpoint=True
                )
            )
 
        step.add_action_set(self._action_set_preprocess_solution)
        step.add_action_set(
            self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement
        )
        step.add_action_set(self._action_set_copy_new_faces_onto_old_faces)
        step.add_action_set(self._action_set_roll_over_update_of_faces)
        step.add_action_set(self._action_set_initial_conditions)
        step.add_action_set(self._action_set_project_patch_onto_faces)
        step.add_action_set(self._action_set_update_face_label)
        step.add_action_set(self._action_set_update_cell_label)
        step.add_action_set(self._action_set_AMR)
        step.add_action_set(self._action_set_postprocess_solution)
 
    def add_actions_to_create_grid(self, step, evaluate_refinement_criterion):
        """
 
        The boundary information is set only once. It is therefore important that
        we ues the face label and initialise it properly.
 
        """
        step.add_action_set(self._action_set_initial_conditions_for_grid_construction)
        step.add_action_set(self._action_set_update_face_label)
        step.add_action_set(self._action_set_update_cell_label)
        if evaluate_refinement_criterion:
            step.add_action_set(self._action_set_AMR_throughout_grid_construction)
        else:
            step.add_action_set(self._action_set_AMR_commit_without_further_analysis)
 
    @property
    def plot_description(
        self,
    ):
        return self._plot_description
 
    @plot_description.setter
    def plot_description(self, description):
        """
 
        Use this one to set a description within the output patch file that tells
        the vis solver what the semantics of the entries are. Typicallly, I use
        a comma-separated list here.
 
        """
        self._plot_description = description
 
    def add_actions_to_plot_solution(self, step, output_path, restart_from_checkpoint=False):
        """!
 
        Add action sets to plotting grid sweep
 
        Consult the discussion in add_actions_to_init_grid() around the order
        of the individual action sets.
 
 
        ## Adaptive mesh refinement
 
        It is important that we have the coupling/dynamic AMR part in here, as
        there might be pending AMR refinement requests that now are realised.
        For the same reason, we need the update of the face label and the update
        of the cell label in here: The AMR might just propagate over into the
        plotting, i.e. we might create new grid entities throughout the plot.
        These entities (faces and cells) have to be initialised properly.
        Otherwise, their un-initialised data will propagate through to the next
        time step.
 
        To make the restriction work, we have to project the solutions onto the
        faces.
 
 
        ## Roll over face data
 
        Das ist ein Kaese, weil das nur einspringt, wenn project wahr ist
 
 
        """
        d = {}
        self._init_dictionary_with_default_parameters(d)
        self.add_entries_to_text_replacement_dictionary(d)
 
        step.add_action_set(
            self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement
        )
        #    step.add_action_set( self._action_set_roll_over_update_of_faces )
        step.add_action_set(self._action_set_update_face_label)
        step.add_action_set(self._action_set_update_cell_label)
        #    step.add_action_set( self._action_set_project_patch_onto_faces )
 
        plot_patches_action_set = peano4.toolbox.blockstructured.PlotPatchesInPeanoBlockFormat(
            filename=output_path + "solution-" + self._name,
            patch=self._patch,
            dataset_name=self._unknown_identifier(),
            description=self._plot_description,
            guard="repositories::plotFilter.plotPatch(marker) and "
            + self._load_cell_data_default_guard(),
            additional_includes="""
#include "exahype2/PlotFilter.h"
#include "../repositories/SolverRepository.h"
""",
            precision="PlotterPrecision",
            time_stamp_evaluation="0.5*(repositories::getMinTimeStamp()+repositories::getMaxTimeStamp())",
            select_dofs=self.select_dofs_to_print,
            restart_preprocess=restart_from_checkpoint
        )
        plot_patches_action_set.descend_invocation_order = self._baseline_action_set_descend_invocation_order
        step.add_action_set(plot_patches_action_set)
 
        if self._plot_grid_properties:
            plot_grid_action_set = peano4.toolbox.PlotGridInPeanoBlockFormat(
                filename=output_path + "grid-" + self._name,
                cell_unknown=None,
                guard="repositories::plotFilter.plotPatch(marker) and "
                + self._load_cell_data_default_guard(),
                additional_includes="""
#include "exahype2/PlotFilter.h"
#include "../repositories/SolverRepository.h"
""",
            )
            plot_grid_action_set.descend_invocation_order = self._baseline_action_set_descend_invocation_order
            step.add_action_set(plot_grid_action_set)
 
        pass
 
    def add_actions_to_checkpoint_solution(self, step, output_path, restart_from_checkpoint=False):
        """!
 
        Add action sets to checkpoint grid sweep
 
        Consult the discussion in add_actions_to_init_grid() around the order
        of the individual action sets.
 
 
        ## Adaptive mesh refinement
 
        It is important that we have the coupling/dynamic AMR part in here, as
        there might be pending AMR refinement requests that now are realised.
        For the same reason, we need the update of the face label and the update
        of the cell label in here: The AMR might just propagate over into the
        plotting, i.e. we might create new grid entities throughout the plot.
        These entities (faces and cells) have to be initialised properly.
        Otherwise, their un-initialised data will propagate through to the next
        time step.
 
        To make the restriction work, we have to project the solutions onto the
        faces.
 
 
        ## Roll over face data
 
        Das ist ein Kaese, weil das nur einspringt, wenn project wahr ist
 
 
        """
        d = {}
        self._init_dictionary_with_default_parameters(d)
        self.add_entries_to_text_replacement_dictionary(d)
 
        step.add_action_set(
            self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement
        )
        #    step.add_action_set( self._action_set_roll_over_update_of_faces )
        step.add_action_set(self._action_set_update_face_label)
        step.add_action_set(self._action_set_update_cell_label)
        #    step.add_action_set( self._action_set_project_patch_onto_faces )
 
        checkpoint_patches_action_set = peano4.toolbox.blockstructured.PlotPatchesInPeanoBlockFormat(
            filename=output_path + "checkpoint-" + self._name,
            patch=self._patch,
            dataset_name=self._unknown_identifier(),
            description=self._plot_description,
            guard=self._load_cell_data_default_guard(),
            additional_includes="""
#include "../repositories/SolverRepository.h"
""",
            precision="PlotterPrecision",
            time_stamp_evaluation="0.5*(repositories::getMinTimeStamp()+repositories::getMaxTimeStamp())",
            select_dofs=None,
            restart_preprocess=restart_from_checkpoint
        )
        checkpoint_patches_action_set.descend_invocation_order = self._baseline_action_set_descend_invocation_order
        step.add_action_set(checkpoint_patches_action_set)
 
        if self._plot_grid_properties:
            checkpoint_grid_action_set = peano4.toolbox.PlotGridInPeanoBlockFormat(
                filename=output_path + "grid-" + self._name,
                cell_unknown=None,
                guard=self._load_cell_data_default_guard(),
                additional_includes="""
#include "../repositories/SolverRepository.h"
""",
            )
            checkpoint_grid_action_set.descend_invocation_order = self._baseline_action_set_descend_invocation_order
            step.add_action_set(checkpoint_grid_action_set)
 
        pass
 
    def add_actions_to_perform_time_step(self, step):
        """
 
        AMR
 
        It is important that we do the inter-grid transfer operators before we
        apply the boundary conditions.
 
        """
        d = {}
        self._init_dictionary_with_default_parameters(d)
        self.add_entries_to_text_replacement_dictionary(d)
 
        step.add_action_set(self._action_set_preprocess_solution)
        step.add_action_set(
            self._action_set_couple_resolution_transitions_and_handle_dynamic_mesh_refinement
        )
        step.add_action_set(self._action_set_roll_over_update_of_faces)
        step.add_action_set(self._action_set_update_face_label)
        step.add_action_set(self._action_set_update_cell_label)
        step.add_action_set(self._action_set_handle_boundary)
        step.add_action_set(self._action_set_update_cell)
        step.add_action_set(self._action_set_project_patch_onto_faces)
        step.add_action_set(self._action_set_compute_final_linear_combination)
        step.add_action_set(self._action_set_AMR)
        step.add_action_set(self._action_set_postprocess_solution)
 
    @abstractmethod
    def add_entries_to_text_replacement_dictionary(self, d):
        pass
 
    def add_implementation_files_to_project(self, namespace, output, dimensions, subdirectory=""):
        """
 
        The ExaHyPE2 project will call this operation when it sets
        up the overall environment.
 
        This routine is typically not invoked by a user.
 
        output: peano4.output.Output
 
        """
        templatefile_prefix = os.path.dirname(os.path.realpath(__file__)) + "/"
 
        if self._solver_template_file_class_name is None:
            templatefile_prefix += self.__class__.__name__
        else:
            templatefile_prefix += self._solver_template_file_class_name
 
        if(subdirectory):
            subdirectory += "/"
 
        abstractHeaderDictionary = {}
        implementationDictionary = {}
        self._init_dictionary_with_default_parameters(abstractHeaderDictionary)
        self._init_dictionary_with_default_parameters(implementationDictionary)
        self.add_entries_to_text_replacement_dictionary(abstractHeaderDictionary)
        self.add_entries_to_text_replacement_dictionary(implementationDictionary)
 
        generated_abstract_header_file = (
            peano4.output.Jinja2TemplatedHeaderImplementationFilePair(
                templatefile_prefix + "Abstract.template.h",
                templatefile_prefix + "Abstract.template.cpp",
                "Abstract" + self._name,
                namespace,
                subdirectory + ".",
                abstractHeaderDictionary,
                True,
                True,
            )
        )
        generated_solver_files = (
            peano4.output.Jinja2TemplatedHeaderImplementationFilePair(
                templatefile_prefix + ".template.h",
                templatefile_prefix + ".template.cpp",
                self._name,
                namespace,
                subdirectory + ".",
                implementationDictionary,
                False,
                True,
            )
        )
 
        output.add(generated_abstract_header_file)
        output.add(generated_solver_files)
        output.makefile.add_h_file(subdirectory + "Abstract" + self._name + ".h", generated=True)
        output.makefile.add_h_file(subdirectory + self._name + ".h", generated=True)
        output.makefile.add_cpp_file(subdirectory + "Abstract" + self._name + ".cpp", generated=True)
        output.makefile.add_cpp_file(subdirectory + self._name + ".cpp", generated=True)
 
        if self._use_var_shortcut:
            generated_shortcut_file = peano4.output.Jinja2TemplatedHeaderFile(
                os.path.dirname(os.path.realpath(__file__))
                + "/"
                + "../VariableShortcuts.template.h",
                "VariableShortcuts",
                namespace,
                subdirectory + ".",
                implementationDictionary,
                True,
                True,
            )
            output.add(generated_shortcut_file)
            output.makefile.add_h_file(subdirectory + "VariableShortcuts.h", generated=True)
 
    def set_solver_constants(self, datastring):
        self._solver_constants = datastring
 
    def add_solver_constants(self, datastring):
        self._solver_constants += datastring
 
    def _init_dictionary_with_default_parameters(self, d):
        """
        This one is called by all algorithmic steps before I invoke
        add_entries_to_text_replacement_dictionary().
 
        See the remarks on set_postprocess_updated_patch_kernel to understand why
        we have to apply the (partially befilled) dictionary to create a new entry
        for this very dictionary.
        """
        d["NUMBER_OF_GRID_CELLS_PER_PATCH_PER_AXIS"] = self._patch.dim[0]
        d["OVERLAP"] = self._overlap
        d["HALO_SIZE"] = int(self._patch_overlap_old.dim[0] / 2)
        d["RK_ORDER"] = self._rk_order
        d["RK_STEPS"] = self.number_of_Runge_Kutta_steps()
        d["SOLVER_INSTANCE"] = self.get_name_of_global_instance()
        d["SOLVER_NAME"] = self._name
        d["UNKNOWN_IDENTIFIER"] = self._unknown_identifier()
        d["NUMBER_OF_UNKNOWNS"] = self._unknowns
        d["NUMBER_OF_AUXILIARY_VARIABLES"] = self._auxiliary_variables
        d["SOLVER_NUMBER"] = 22
 
        d["ASSERTION_WITH_1_ARGUMENTS"] = "nonCriticalAssertion1"
        d["ASSERTION_WITH_2_ARGUMENTS"] = "nonCriticalAssertion2"
        d["ASSERTION_WITH_3_ARGUMENTS"] = "nonCriticalAssertion3"
        d["ASSERTION_WITH_4_ARGUMENTS"] = "nonCriticalAssertion4"
        d["ASSERTION_WITH_5_ARGUMENTS"] = "nonCriticalAssertion5"
        d["ASSERTION_WITH_6_ARGUMENTS"] = "nonCriticalAssertion6"
 
        if self._min_meshcell_h > self._max_meshcell_h:
            raise Exception("min/max h are inconsistent")
        d["MAX_GRID_CELL_H"] = self._max_meshcell_h
        d["MIN_GRID_CELL_H"] = self._min_meshcell_h
 
        d["SOLVER_CONSTANTS"] = self._solver_constants
 
        d["SOLVER_INCLUDES"] = self.user_solver_includes
 
        d[
            "BOUNDARY_CONDITIONS_IMPLEMENTATION"
        ] = self._boundary_conditions_implementation
        d[
            "REFINEMENT_CRITERION_IMPLEMENTATION"
        ] = self._refinement_criterion_implementation
        d["INITIAL_CONDITIONS_IMPLEMENTATION"] = self._initial_conditions_implementation
 
        d["COMPUTE_KERNEL_CALL"] = jinja2.Template(
            self._compute_kernel_call, undefined=jinja2.DebugUndefined
        ).render(**d)
 
        d["RECONSTRUCTION_KERNEL_CALL"] = jinja2.Template(self._reconstruction_kernel_call, undefined=jinja2.DebugUndefined).render(**d)
        d["PRIMARY_VARS_INDICES"] = self._primary_variables_indices
        d["AUXILIARY_VARS_INDICES"] = self._auxiliary_variables_indices
 
        d["ABSTRACT_SOLVER_USER_DECLARATIONS"] = jinja2.Template(
            self._abstract_solver_user_declarations, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["ABSTRACT_SOLVER_USER_DEFINITIONS"] = jinja2.Template(
            self._abstract_solver_user_definitions, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["SOLVER_USER_DECLARATIONS"] = jinja2.Template(
            self._solver_user_declarations, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["SOLVER_USER_DEFINITIONS"] = jinja2.Template(
            self._solver_user_definitions, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["START_TIME_STEP_IMPLEMENTATION"] = jinja2.Template(
            self._start_time_step_implementation, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["FINISH_TIME_STEP_IMPLEMENTATION"] = jinja2.Template(
            self._finish_time_step_implementation, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["CONSTRUCTOR_IMPLEMENTATION"] = jinja2.Template(
            self._constructor_implementation, undefined=jinja2.DebugUndefined
        ).render(**d)
 
        d["PREPROCESS_RECONSTRUCTED_PATCH"] = jinja2.Template(
            self._preprocess_reconstructed_patch, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["POSTPROCESS_UPDATED_PATCH"] = jinja2.Template(
            self._postprocess_updated_patch, undefined=jinja2.DebugUndefined
        ).render(**d)
 
        d["COMPUTE_TIME_STEP_SIZE"] = jinja2.Template(
            self._compute_time_step_size, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["COMPUTE_NEW_TIME_STEP_SIZE"] = jinja2.Template(
            self._compute_new_time_step_size, undefined=jinja2.DebugUndefined
        ).render(**d)
        d["COMPUTE_MAX_EIGENVALUE"] = self._compute_eigenvalue
 
        d["KERNEL_NAMESPACE"] = self._kernel_namespace
 
        d["USE_VARIABLE_SHORTCUT"] = self._use_var_shortcut
        d["VARIABLE_NAMES"] = self._variable_names
        d["VARIABLE_POSITIONS"] = self._variable_pos
 
    @property
    def unknowns(self):
        return self._unknowns
 
    @property
    def patch_size(self):
        return self._patch_size
 
    @property
    def auxiliary_variables(self):
        return self._auxiliary_variables
 
    @patch_size.setter
    def patch_size(self, value):
        self._patch_size = value
        self.create_data_structures()
        self.create_action_sets()
 
    @unknowns.setter
    def unknowns(self, value):
        self._unknowns = value
        self.create_data_structures()
        self.create_action_sets()
 
    @auxiliary_variables.setter
    def auxiliary_variables(self, value):
        self._auxiliary_variables = value
        self.create_data_structures()
        self.create_action_sets()
 
    @property
    def preprocess_reconstructed_patch(self):
        return self._preprocess_reconstructed_patch
 
    @preprocess_reconstructed_patch.setter
    def preprocess_reconstructed_patch(self, kernel):
        """!
 
        Please consult exahype2.solvers.fv.FV.preprocess_reconstructed_patch() for
        a documentation on this routine.
 
        """
        self._preprocess_reconstructed_patch = kernel
        self.create_data_structures()
        self.create_action_sets()
 
    @property
    def name(self):
        return self._name
 
    @property
    def postprocess_updated_patch(self):
        return self._postprocess_updated_patch
 
    @postprocess_updated_patch.setter
    def postprocess_updated_patch(self, kernel):
        """
 
          Define a postprocessing routine over the data
 
          The postprocessing kernel often looks similar to the following code:
 
        {
          int index = 0;
          dfor( volume, {{NUMBER_OF_GRID_CELLS_PER_PATCH_PER_AXIS}} ) {
            enforceCCZ4constraints( newQ+index );
            index += {{NUMBER_OF_UNKNOWNS}} + {{NUMBER_OF_AUXILIARY_VARIABLES}};
          }
        }
 
 
          Within this kernel, you have at least the following variables available:
 
          - newQ This is a pointer to the whole data structure (one large
              array).
              The patch is not supplemented by a halo layer.
          - oldQWithHalo This is a pointer to the data snapshot before the
              actual update. This data is combined with the halo layer, i.e. if you
              work with 7x7 patches and a halo of 2, the pointer points to a 11x11
              patch.
          - marker
 
          Furthermore, you can use all the symbols (via Jinja2 syntax) from
          _init_dictionary_with_default_parameters().
 
          kernel: String
            C++ code that holds the postprocessing kernel
 
        """
        self._postprocess_updated_patch = kernel
        self.create_data_structures()
        self.create_action_sets()
 
    @property
    def overlap(self):
        return self._overlap
 
    @overlap.setter
    def overlap(self, value):
        if value < 1:
            raise Exception(
                "Halo (overlap) size has to be bigger than zero but was {}".format(
                    value
                )
            )
        self._overlap = value
        self.create_data_structures()
        self.create_action_sets()
 
    @property
    def interpolation(self):
        return self._interpolation
 
    @interpolation.setter
    def interpolation(self, value):
        """
 
        Set the interpolation scheme. If you rely on a built-in operation, then this
        call is all you have to do. Some ExaHyPE solvers however require each solver
        to provide special matrices/operators for some interpolation/restriction
        variants. If this is the case, you still have to add these matrices manually
        to your solver.
 
        """
        self._interpolation = value
 
        self.create_data_structures()
        self.create_action_sets()
 
    @property
    def restriction(self):
        """
 
        Set the restriction scheme. If you rely on a built-in operation, then this
        call is all you have to do. Some ExaHyPE solvers however require each solver
        to provide special matrices/operators for some interpolation/restriction
        variants. If this is the case, you still have to add these matrices manually
        to your solver.
 
        """
        return self._restriction
 
    @restriction.setter
    def restriction(self, value):
        self._restriction = value
 
        self.create_data_structures()
        self.create_action_sets()
 
    def switch_storage_scheme(
        self,
        cell_data_storage: Storage,
        face_data_storage: Storage,
    ):
        """
 
        By default, we hold all data on the call stacks. You can explicitly switch
        to storage on the heap via smart pointers.
 
        @see create_data_structures()
 
        """
        assert isinstance(cell_data_storage, Storage)
        assert isinstance(face_data_storage, Storage)
        
        self._cell_data_storage = cell_data_storage
        self._face_data_storage = face_data_storage
 
        self.create_data_structures()
        self.create_action_sets()