SSP_RungeKutta< ORDER > Class Template Reference

Inheritance diagram for SSP_RungeKutta< ORDER >:

Public Member Functions
	SSP_RungeKutta ()
	Constructor, set the type. More...
	SSP_RungeKutta (const SSP_RungeKutta &)
	Broken copy constructor. More...
void	operator= (const SSP_RungeKutta &)
	Broken assignment operator. More...
void	timestep (ExplicitTimeSteppableObject *const &object_pt, const double &dt)
	Function that is used to advance time in the object. More...
void	timestep (ExplicitTimeSteppableObject *const &object_pt, const double &dt)
	Explicit specialisation for second-order RK scheme. More...
Public Member Functions inherited from oomph::ExplicitTimeStepper
	ExplicitTimeStepper ()
	Empty Constructor. More...
	ExplicitTimeStepper (const ExplicitTimeStepper &)=delete
	Broken copy constructor. More...
void	operator= (const ExplicitTimeStepper &)=delete
	Broken assignment operator. More...
virtual	~ExplicitTimeStepper ()
	Empty virtual destructor — no memory is allocated in this class. More...

Additional Inherited Members
Protected Attributes inherited from oomph::ExplicitTimeStepper
std::string	Type

Detailed Description

template<unsigned ORDER>
class SSP_RungeKutta< ORDER >

=========================================================== Strong Stability preserving Runge Kutta Timestepping

Constructor & Destructor Documentation

SSP_RungeKutta() [1/2]

template<unsigned ORDER>

SSP_RungeKutta< ORDER >::SSP_RungeKutta ( )

inline

Constructor, set the type.

  {
   Type="SSP_RungeKutta";
  }

SSP_RungeKutta() [2/2]

template<unsigned ORDER>

SSP_RungeKutta< ORDER >::SSP_RungeKutta ( const SSP_RungeKutta< ORDER > &  )

inline

Broken copy constructor.

  { 
   BrokenCopy::broken_copy("SS_PRungeKutta");
  } 

References oomph::BrokenCopy::broken_copy().

Member Function Documentation

operator=()

template<unsigned ORDER>

void SSP_RungeKutta< ORDER >::operator= ( const SSP_RungeKutta< ORDER > &  )

inline

Broken assignment operator.

  {
   BrokenCopy::broken_assign("SSP_RungeKutta");
  } 

References oomph::BrokenCopy::broken_assign().

timestep() [1/2]

template<unsigned ORDER>

void SSP_RungeKutta< ORDER >::timestep ( ExplicitTimeSteppableObject *const &  object_pt, const double &  dt  )

virtual

Function that is used to advance time in the object.

Implements oomph::ExplicitTimeStepper.

{
 std::ostringstream error_stream;
 error_stream << "Timestep not implemented for order " << ORDER << "\n";
 throw OomphLibError(error_stream.str(),
                     OOMPH_CURRENT_FUNCTION,
                     OOMPH_EXCEPTION_LOCATION);
}

References OOMPH_CURRENT_FUNCTION, and OOMPH_EXCEPTION_LOCATION.

timestep() [2/2]

void SSP_RungeKutta< 2 >::timestep	(	ExplicitTimeSteppableObject *const &	object_pt,
		const double &	dt
	)

Explicit specialisation for second-order RK scheme.

{
 object_pt->actions_before_explicit_timestep();
 
 //Store the initial values and initial time
 DoubleVector u;
 object_pt->get_dofs(u);
 
 // Stage 1
 // ============================================================
 object_pt->actions_before_explicit_stage();
 
 //Now get the first unknowns
 DoubleVector k1;
 object_pt->get_dvaluesdt(k1);
 
 //Add to the residuals
 object_pt->add_to_dofs(dt,k1);
 //Increment the time
 object_pt->time() += dt;
 object_pt->actions_after_explicit_stage();
 
 // Stage 2
 // ============================================================ 
 object_pt->actions_before_explicit_stage();
 
 //Get the next unknowns
 DoubleVector k2;
 object_pt->get_dvaluesdt(k2);
 
 //Add to the residuals so that the current value of the unknowns
 //is the result of two forward Euler steps of time dt
 object_pt->add_to_dofs(dt,k2);
 
 //Set the final values of the unknowns by taking the average of the
 //initial value and the result of the two forward Euler steps
 
 //Get the current value 
 DoubleVector u_final;
 object_pt->get_dofs(u_final);
 
 //Now take the average
 unsigned n_dof = u_final.nrow();
 for(unsigned n=0;n<n_dof;n++)
  {
   u_final[n] += u[n];
   u_final[n] *= 0.5;
  }
 
 //Set the dofs to the new final value
 object_pt->set_dofs(u_final);
 
 //Time remains the same
 
 // Actions functions
 object_pt->actions_after_explicit_stage();
 object_pt->actions_after_explicit_timestep();
}

References oomph::ExplicitTimeSteppableObject::actions_after_explicit_stage(), oomph::ExplicitTimeSteppableObject::actions_after_explicit_timestep(), oomph::ExplicitTimeSteppableObject::actions_before_explicit_stage(), oomph::ExplicitTimeSteppableObject::actions_before_explicit_timestep(), oomph::ExplicitTimeSteppableObject::add_to_dofs(), oomph::ExplicitTimeSteppableObject::get_dofs(), oomph::ExplicitTimeSteppableObject::get_dvaluesdt(), n, oomph::DistributableLinearAlgebraObject::nrow(), oomph::ExplicitTimeSteppableObject::set_dofs(), and oomph::ExplicitTimeSteppableObject::time().

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The documentation for this class was generated from the following file:

• ff_step.cc