MFEM  v4.3.0
Finite element discretization library
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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)
void Init (TimeDependentOperator &f_) override
 Associate a TimeDependentOperator with the ODE solver. More...
void Step (Vector &x, double &t, double &dt) override
 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 int GetMaxStateSize ()
 Function for getting and setting the state vectors. More...
virtual int GetStateSize ()
virtual const VectorGetStateVector (int i)
virtual void GetStateVector (int i, Vector &state)
virtual void SetStateVector (int i, Vector &state)
virtual ~ODESolver ()

Protected Attributes

double gamma
Vector k
Vector y
- Protected Attributes inherited from mfem::ODESolver
 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 420 of file ode.hpp.

Constructor & Destructor Documentation

mfem::SDIRK23Solver::SDIRK23Solver ( int  gamma_opt = 1)

Definition at line 571 of file ode.cpp.

Member Function Documentation

void mfem::SDIRK23Solver::Init ( TimeDependentOperator f_)

Associate a TimeDependentOperator with the ODE solver.

This method has to be called:

Reimplemented from mfem::ODESolver.

Definition at line 591 of file ode.cpp.

void mfem::SDIRK23Solver::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].

[in,out]xApproximate solution.
[in,out]tTime associated with the approximate solution x.
[in,out]dtTime 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 598 of file ode.cpp.

Member Data Documentation

double mfem::SDIRK23Solver::gamma

Definition at line 423 of file ode.hpp.

Vector mfem::SDIRK23Solver::k

Definition at line 424 of file ode.hpp.

Vector mfem::SDIRK23Solver::y

Definition at line 424 of file ode.hpp.

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