mfem::SDIRK23Solver Class Reference

#include <ode.hpp>

Inheritance diagram for mfem::SDIRK23Solver:

Collaboration diagram for mfem::SDIRK23Solver:

Public Member Functions
	SDIRK23Solver (int gamma_opt=1)
virtual void	Init (TimeDependentOperator &_f)
	Associate a TimeDependentOperator with the ODE solver. More...
virtual void	Step (Vector &x, double &t, double &dt)
	Perform a time step from time t [in] to time t [out] based on the requested step size dt [in]. More...
Public Member Functions inherited from mfem::ODESolver
	ODESolver ()
virtual void	Run (Vector &x, double &t, double &dt, double tf)
	Perform time integration from time t [in] to time tf [in]. More...
virtual	~ODESolver ()

Protected Attributes
double	gamma
Vector	k
Vector	y
Protected Attributes inherited from mfem::ODESolver
TimeDependentOperator *	f
	Pointer to the associated TimeDependentOperator. More...
MemoryType	mem_type

Detailed Description

Two stage, singly diagonal implicit Runge-Kutta (SDIRK) methods; the choices for gamma_opt are: 0 - 3rd order method, not A-stable 1 - 3rd order method, A-stable, not L-stable (default) 2 - 2nd order method, L-stable 3 - 2nd order method, L-stable (has solves outside [t,t+dt]).

Definition at line 241 of file ode.hpp.

Constructor & Destructor Documentation

mfem::SDIRK23Solver::SDIRK23Solver

(

int

gamma_opt = 1

)

Definition at line 377 of file ode.cpp.

Member Function Documentation

void mfem::SDIRK23Solver::Init ( TimeDependentOperator &  f )

virtual

Associate a TimeDependentOperator with the ODE solver.

This method has to be called:

• Before the first call to Step().
• When the dimensions of the associated TimeDependentOperator change.
• When a time stepping sequence has to be restarted.
• To change the associated TimeDependentOperator.

Reimplemented from mfem::ODESolver.

Definition at line 397 of file ode.cpp.

void mfem::SDIRK23Solver::Step ( Vector &  x, double &  t, double &  dt  )

virtual

Perform a time step from time t [in] to time t [out] based on the requested step size dt [in].

Parameters

[in,out]	x	Approximate solution.
[in,out]	t	Time associated with the approximate solution x.
[in,out]	dt	Time step size.

The following rules describe the common behavior of the method:

• The input x [in] is the approximate solution for the input time t [in].
• The input dt [in] is the desired time step size, defining the desired target time: t [target] = t [in] + dt [in].
• The output x [out] is the approximate solution for the output time t [out].
• The output dt [out] is the last time step taken by the method which may be smaller or larger than the input dt [in] value, e.g. because of time step control.
• The method may perform more than one time step internally; in this case dt [out] is the last internal time step size.
• The output value of t [out] may be smaller or larger than t [target], however, it is not smaller than t [in] + dt [out], if at least one internal time step was performed.
• The value x [out] may be obtained by interpolation using internally stored data.
• In some cases, the contents of x [in] may not be used, e.g. when x [out] from a previous Step() call was obtained by interpolation.
• In consecutive calls to this method, the output t [out] of one Step() call has to be the same as the input t [in] to the next Step() call.
• If the previous rule has to be broken, e.g. to restart a time stepping sequence, then the ODE solver must be re-initialized by calling Init() between the two Step() calls.

Implements mfem::ODESolver.

Definition at line 404 of file ode.cpp.

Member Data Documentation

double mfem::SDIRK23Solver::gamma

protected

Definition at line 244 of file ode.hpp.

Vector mfem::SDIRK23Solver::k

protected

Definition at line 245 of file ode.hpp.

Vector mfem::SDIRK23Solver::y

protected

Definition at line 245 of file ode.hpp.

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

• linalg/ode.hpp
• linalg/ode.cpp