ComputeMaxEigenvalue.py

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# 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 peano4.api
 
from .AbstractRKFD4ActionSet import AbstractRKFD4ActionSet
 
 
class ComputeMaxEigenvalue(AbstractRKFD4ActionSet):
    """!
 
    Store the maximum eigenvalue over all grid cells of a patch
 
    The action set runs after the final linear combination of a Runge-Kutta
    step, i.e. it sees the solution of the next time step in solver._patch.
    It stores the maximum eigenvalue in solver._max_eigenvalue, from where
    exahype2.api.rkfd4.actionsets.ComputeTimeStepSize reduces it into the
    next time step size.
 
    """
 
    def __init__(self, solver, guard):
        """!
 
        @param solver: exahype2.api.Solver
          Has to have an exahype2.api.rkfd4.CentralDifferencesWithRungeKutta
          with adaptive time stepping as numerical scheme, which has already
          constructed its kernel calls.
 
        @param guard: str
          C++ boolean expression, evaluated per cell in touchCellFirstTime.
 
        """
        AbstractRKFD4ActionSet.__init__(self, solver)
        self.guard = guard
 
    def get_body_of_operation(self, operation_name):
        if (
            operation_name
            != peano4.api.solversteps.ActionSet.OPERATION_TOUCH_CELL_FIRST_TIME
        ):
            return ""
        instance = self._solver.get_name_of_global_instance()
        return f"""
  ::exahype2::CellData patchData(
    fineGridCell{self._solver._patch.name}.value,
    marker.x(),
    marker.h(),
    repositories::{instance}.getMinTimeStamp(),
    repositories::{instance}.getMinTimeStepSize(),
    fineGridCell{self._solver._patch.name}.value
  );
  {self._solver.numerical_scheme.max_eigenvalue_kernel_call}
  fineGridCell{self._solver._max_eigenvalue.name}.setMaxEigenvalue( 0, patchData.maxEigenvalue[0] );
"""
 
    def get_guard_of_operation(self, operation_name):
        if (
            operation_name
            == peano4.api.solversteps.ActionSet.OPERATION_TOUCH_CELL_FIRST_TIME
        ):
            return self.guard
        return "true"
 
    def get_action_set_name(self):
        return __name__.replace(".py", "").replace(".", "_")