Line data    Source code

       1           0 : // Distributed under the MIT License.
       2             : // See LICENSE.txt for details.
       3             : 
       4             : #pragma once
       5             : 
       6             : #include <cstddef>
       7             : 
       8             : #include "DataStructures/TaggedVariant.hpp"
       9             : #include "Options/String.hpp"
      10             : #include "Time/TimeSteppers/RungeKutta.hpp"
      11             : #include "Utilities/Serialization/CharmPupable.hpp"
      12             : #include "Utilities/TMPL.hpp"
      13             : 
      14             : namespace TimeSteppers {
      15             : /*!
      16             :  * \ingroup TimeSteppersGroup
      17             :  * \brief A fifth order RK method constructed with fewer restrictions
      18             :  * on its coefficients than is common.  On a standard test suite, it
      19             :  * was found to be roughly 10% more efficient than
      20             :  * DormandPrince5.\cite Tsitouras2011.
      21             :  *
      22             :  * The CFL stable step size is 1.7534234969024887.
      23             :  */
      24           1 : class Rk5Tsitouras : public RungeKutta {
      25             :  public:
      26           0 :   using options = tmpl::list<>;
      27           0 :   static constexpr Options::String help = {
      28             :       "An efficient 5th-order Runge-Kutta time stepper."};
      29             : 
      30           0 :   Rk5Tsitouras() = default;
      31           0 :   Rk5Tsitouras(const Rk5Tsitouras&) = default;
      32           0 :   Rk5Tsitouras& operator=(const Rk5Tsitouras&) = default;
      33           0 :   Rk5Tsitouras(Rk5Tsitouras&&) = default;
      34           0 :   Rk5Tsitouras& operator=(Rk5Tsitouras&&) = default;
      35           0 :   ~Rk5Tsitouras() override = default;
      36             : 
      37           1 :   variants::TaggedVariant<Tags::FixedOrder, Tags::VariableOrder> order()
      38             :       const override;
      39             : 
      40           1 :   double stable_step() const override;
      41             : 
      42           0 :   WRAPPED_PUPable_decl_template(Rk5Tsitouras);  // NOLINT
      43             : 
      44           0 :   explicit Rk5Tsitouras(CkMigrateMessage* /*msg*/);
      45             : 
      46           0 :   const ButcherTableau& butcher_tableau() const override;
      47             : };
      48             : 
      49           0 : inline bool constexpr operator==(const Rk5Tsitouras& /*lhs*/,
      50             :                                  const Rk5Tsitouras& /*rhs*/) {
      51             :   return true;
      52             : }
      53             : 
      54           0 : inline bool constexpr operator!=(const Rk5Tsitouras& /*lhs*/,
      55             :                                  const Rk5Tsitouras& /*rhs*/) {
      56             :   return false;
      57             : }
      58             : }  // namespace TimeSteppers