Criteria for terminating a simulation

ASPECT allows for different ways of terminating a simulation. For example, the simulation may have reached a final time specified in the input file. However, it also allows for ways to terminate a simulation when it has reached a steady state (or, rather, some criterion determines that it is close enough to steady state), or by an external action such as placing a specially named file in the output directory. The criteria determining termination of a simulation are all implemented in plugins. The parameters describing these criteria are listed in Termination criteria.

To implement a termination criterion, you need to overload the aspect::TerminationCriteria::Interface class and use the ASPECT_REGISTER_TERMINATION_CRITERION macro to register your new class. The implementation of the new class should be in namespace aspect::TerminationCriteria.

Specifically, your new class needs to implement the following basic interface:

template <int dim>
    class aspect::TerminationCriteria::Interface
    {
      public:
        virtual
        bool
        execute () const = 0;

        static
        void
        declare_parameters (ParameterHandler &prm);

        virtual
        void
        parse_parameters (ParameterHandler &prm);
    };

The first of these functions returns a value that indicates whether the simulation should be terminated. Typical examples can be found in the existing implementations in the source/termination_criteria directory. As usual, your termination criterion implementation will likely need to be derived from the SimulatorAccess to get access to the current state of the simulation.

The remaining functions are obvious, and are also discussed in the documentation of this interface class at aspect::TerminationCriteria::Interface. The purpose of the last two functions has been discussed in the general overview of plugins above.