libMesh::TwostepTimeSolver Class Reference

#include <twostep_time_solver.h>

Inheritance diagram for libMesh::TwostepTimeSolver:

Public Types
typedef AdaptiveTimeSolver	Parent
typedef DifferentiableSystem	sys_type

Public Member Functions
	TwostepTimeSolver (sys_type &s)
	~TwostepTimeSolver ()
virtual void	solve () override
virtual void	init () override
virtual void	reinit () override
virtual void	advance_timestep () override
virtual Real	error_order () const override
virtual bool	element_residual (bool get_jacobian, DiffContext &) override
virtual bool	side_residual (bool get_jacobian, DiffContext &) override
virtual bool	nonlocal_residual (bool get_jacobian, DiffContext &) override
virtual std::unique_ptr< DiffSolver > &	diff_solver () override
virtual std::unique_ptr< LinearSolver< Number > > &	linear_solver () override
virtual unsigned int	time_order () const override
virtual void	init_data () override
virtual void	adjoint_advance_timestep () override
virtual void	retrieve_timestep () override
Number	old_nonlinear_solution (const dof_id_type global_dof_number) const
virtual Real	du (const SystemNorm &norm) const override
virtual bool	is_steady () const override
virtual void	before_timestep ()
const sys_type &	system () const
sys_type &	system ()
void	set_solution_history (const SolutionHistory &_solution_history)
bool	is_adjoint () const
void	set_is_adjoint (bool _is_adjoint_value)

Static Public Member Functions
static std::string	get_info ()
static void	print_info (std::ostream &out=libMesh::out)
static unsigned int	n_objects ()
static void	enable_print_counter_info ()
static void	disable_print_counter_info ()

Public Attributes
std::unique_ptr< UnsteadySolver >	core_time_solver
SystemNorm	component_norm
std::vector< float >	component_scale
Real	target_tolerance
Real	upper_tolerance
Real	max_deltat
Real	min_deltat
Real	max_growth
bool	global_tolerance
std::unique_ptr< NumericVector< Number > >	old_local_nonlinear_solution
bool	quiet
unsigned int	reduce_deltat_on_diffsolver_failure

Protected Types
typedef bool(DifferentiablePhysics::*	ResFuncType) (bool, DiffContext &)
typedef void(DiffContext::*	ReinitFuncType) (Real)
typedef std::map< std::string, std::pair< unsigned int, unsigned int > >	Counts

Protected Member Functions
virtual Real	calculate_norm (System &, NumericVector< Number > &)
void	prepare_accel (DiffContext &context)
bool	compute_second_order_eqns (bool compute_jacobian, DiffContext &c)
void	increment_constructor_count (const std::string &name)
void	increment_destructor_count (const std::string &name)

Protected Attributes
Real	last_deltat
bool	first_solve
bool	first_adjoint_step
std::unique_ptr< DiffSolver >	_diff_solver
std::unique_ptr< LinearSolver< Number > >	_linear_solver
sys_type &	_system
std::unique_ptr< SolutionHistory >	solution_history

Static Protected Attributes
static Counts	_counts
static Threads::atomic< unsigned int >	_n_objects
static Threads::spin_mutex	_mutex
static bool	_enable_print_counter = true

Detailed Description

This class wraps another UnsteadySolver derived class, and compares the results of timestepping with deltat and timestepping with 2*deltat to adjust future timestep lengths.

Currently this class only works on fully coupled Systems

This class is part of the new DifferentiableSystem framework, which is still experimental. Users of this framework should beware of bugs and future API changes.

Author

Roy H. Stogner

Date

2007

Definition at line 50 of file twostep_time_solver.h.

Member Typedef Documentation

Counts

typedef std::map<std::string, std::pair<unsigned int, unsigned int> > libMesh::ReferenceCounter::Counts

protectedinherited

Data structure to log the information. The log is identified by the class name.

Definition at line 117 of file reference_counter.h.

Parent

typedef AdaptiveTimeSolver libMesh::TwostepTimeSolver::Parent

The parent class

Definition at line 56 of file twostep_time_solver.h.

ReinitFuncType

typedef void(DiffContext::* libMesh::TimeSolver::ReinitFuncType) (Real)

protectedinherited

Definition at line 273 of file time_solver.h.

ResFuncType

typedef bool(DifferentiablePhysics::* libMesh::TimeSolver::ResFuncType) (bool, DiffContext &)

protectedinherited

Definitions of argument types for use in refactoring subclasses.

Definition at line 271 of file time_solver.h.

sys_type

typedef DifferentiableSystem libMesh::TimeSolver::sys_type

inherited

The type of system

Definition at line 65 of file time_solver.h.

Constructor & Destructor Documentation

TwostepTimeSolver()

libMesh::TwostepTimeSolver::TwostepTimeSolver ( sys_type &  s )

explicit

Constructor. Requires a reference to the system to be solved.

Definition at line 29 of file twostep_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

  : AdaptiveTimeSolver(s)

{
  // We start with a reasonable time solver: implicit Euler
  core_time_solver.reset(new EulerSolver(s));
}

~TwostepTimeSolver()

libMesh::TwostepTimeSolver::~TwostepTimeSolver

(

)

Destructor.

Definition at line 39 of file twostep_time_solver.C.

{
}

Member Function Documentation

adjoint_advance_timestep()

void libMesh::UnsteadySolver::adjoint_advance_timestep ( )

overridevirtualinherited

This method advances the adjoint solution to the previous timestep, after an adjoint_solve() has been performed. This will be done before every UnsteadySolver::adjoint_solve().

Reimplemented from libMesh::TimeSolver.

Reimplemented in libMesh::NewmarkSolver.

Definition at line 178 of file unsteady_solver.C.

References libMesh::TimeSolver::_system, libMesh::DifferentiableSystem::deltat, libMesh::UnsteadySolver::first_adjoint_step, libMesh::System::get_dof_map(), libMesh::DofMap::get_send_list(), libMesh::System::get_vector(), libMesh::NumericVector< T >::localize(), libMesh::UnsteadySolver::old_local_nonlinear_solution, libMesh::TimeSolver::solution_history, and libMesh::System::time.

{
  // On the first call of this function, we dont save the adjoint solution or
  // decrement the time, we just call the retrieve function below
  if (!first_adjoint_step)
    {
      // Call the store function to store the last adjoint before decrementing the time
      solution_history->store();
      // Decrement the system time
      _system.time -= _system.deltat;
    }
  else
    {
      first_adjoint_step = false;
    }

  // Retrieve the primal solution vectors at this time using the
  // solution_history object
  solution_history->retrieve();

  // Dont forget to localize the old_nonlinear_solution !
  _system.get_vector("_old_nonlinear_solution").localize
    (*old_local_nonlinear_solution,
     _system.get_dof_map().get_send_list());
}

advance_timestep()

void libMesh::AdaptiveTimeSolver::advance_timestep ( )

overridevirtualinherited

This method advances the solution to the next timestep, after a solve() has been performed. Often this will be done after every UnsteadySolver::solve(), but adaptive mesh refinement and/or adaptive time step selection may require some solve() steps to be repeated.

Reimplemented from libMesh::UnsteadySolver.

Definition at line 87 of file adaptive_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::UnsteadySolver::first_solve, libMesh::System::get_vector(), libMesh::AdaptiveTimeSolver::last_deltat, libMesh::System::solution, and libMesh::System::time.

{
  NumericVector<Number> & old_nonlinear_soln =
    _system.get_vector("_old_nonlinear_solution");
  NumericVector<Number> & nonlinear_solution =
    *(_system.solution);

  old_nonlinear_soln = nonlinear_solution;

  if (!first_solve)
    _system.time += last_deltat;
}

before_timestep()

virtual void libMesh::TimeSolver::before_timestep ( )

inlinevirtualinherited

This method is for subclasses or users to override to do arbitrary processing between timesteps

Definition at line 167 of file time_solver.h.

{}

calculate_norm()

Real libMesh::AdaptiveTimeSolver::calculate_norm ( System &  s, NumericVector< Number > &  v  )

protectedvirtualinherited

A helper function to calculate error norms

Definition at line 155 of file adaptive_time_solver.C.

References libMesh::System::calculate_norm(), and libMesh::AdaptiveTimeSolver::component_norm.

Referenced by solve().

{
  return s.calculate_norm(v, component_norm);
}

compute_second_order_eqns()

bool libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns ( bool  compute_jacobian, DiffContext &  c  )

protectedinherited

If there are second order variables, then we need to compute their residual equations and corresponding Jacobian. The residual equation will simply be , where is the second order variable add by the user and is the variable added by the time-solver as the "velocity" variable.

Definition at line 32 of file first_order_unsteady_solver.C.

References libMesh::TimeSolver::_system, libMesh::DiffContext::get_dof_indices(), libMesh::DiffContext::get_elem_jacobian(), libMesh::DiffContext::get_elem_residual(), libMesh::DiffContext::get_elem_solution_derivative(), libMesh::DiffContext::get_elem_solution_rate_derivative(), libMesh::FEMContext::get_element_fe(), libMesh::FEMContext::get_element_qrule(), libMesh::DifferentiableSystem::get_second_order_dot_var(), libMesh::DiffContext::get_system(), libMesh::FEMContext::interior_rate(), libMesh::FEMContext::interior_value(), libMesh::DifferentiablePhysics::is_second_order_var(), libMesh::QBase::n_points(), libMesh::DiffContext::n_vars(), libMesh::Variable::type(), and libMesh::System::variable().

Referenced by libMesh::EulerSolver::_general_residual(), libMesh::Euler2Solver::_general_residual(), libMesh::EulerSolver::element_residual(), libMesh::Euler2Solver::element_residual(), libMesh::EulerSolver::nonlocal_residual(), and libMesh::Euler2Solver::nonlocal_residual().

{
  FEMContext & context = cast_ref<FEMContext &>(c);

  unsigned int n_qpoints = context.get_element_qrule().n_points();

  for (unsigned int var = 0; var != context.n_vars(); ++var)
    {
      if (!this->_system.is_second_order_var(var))
        continue;

      unsigned int dot_var = this->_system.get_second_order_dot_var(var);

      // We're assuming that the FE space for var and dot_var are the same
      libmesh_assert( context.get_system().variable(var).type() ==
                      context.get_system().variable(dot_var).type() );

      FEBase * elem_fe = nullptr;
      context.get_element_fe( var, elem_fe );

      const std::vector<Real> & JxW = elem_fe->get_JxW();

      const std::vector<std::vector<Real>> & phi = elem_fe->get_phi();

      const unsigned int n_dofs = cast_int<unsigned int>
        (context.get_dof_indices(dot_var).size());

      DenseSubVector<Number> & Fu = context.get_elem_residual(var);
      DenseSubMatrix<Number> & Kuu = context.get_elem_jacobian( var, var );
      DenseSubMatrix<Number> & Kuv = context.get_elem_jacobian( var, dot_var );

      for (unsigned int qp = 0; qp != n_qpoints; ++qp)
        {
          Number udot, v;
          context.interior_rate(var, qp, udot);
          context.interior_value(dot_var, qp, v);

          for (unsigned int i = 0; i < n_dofs; i++)
            {
              Fu(i) += JxW[qp]*(udot-v)*phi[i][qp];

              if (compute_jacobian)
                {
                  Number rate_factor = JxW[qp]*context.get_elem_solution_rate_derivative()*phi[i][qp];
                  Number soln_factor = JxW[qp]*context.get_elem_solution_derivative()*phi[i][qp];

                  Kuu(i,i) += rate_factor*phi[i][qp];
                  Kuv(i,i) -= soln_factor*phi[i][qp];

                  for (unsigned int j = i+1; j < n_dofs; j++)
                    {
                      Kuu(i,j) += rate_factor*phi[j][qp];
                      Kuu(j,i) += rate_factor*phi[j][qp];

                      Kuv(i,j) -= soln_factor*phi[j][qp];
                      Kuv(j,i) -= soln_factor*phi[j][qp];
                    }
                }
            }
        }
    }

  return compute_jacobian;
}

diff_solver()

std::unique_ptr< DiffSolver > & libMesh::AdaptiveTimeSolver::diff_solver ( )

overridevirtualinherited

An implicit linear or nonlinear solver to use at each timestep.

Reimplemented from libMesh::TimeSolver.

Definition at line 141 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  return core_time_solver->diff_solver();
}

disable_print_counter_info()

void libMesh::ReferenceCounter::disable_print_counter_info ( )

staticinherited

Definition at line 106 of file reference_counter.C.

References libMesh::ReferenceCounter::_enable_print_counter.

Referenced by libMesh::LibMeshInit::LibMeshInit().

{
  _enable_print_counter = false;
  return;
}

du()

Real libMesh::UnsteadySolver::du ( const SystemNorm &  norm ) const

overridevirtualinherited

Computes the size of ||u^{n+1} - u^{n}|| in some norm.

Note

While you can always call this function, its result may or may not be very meaningful. For example, if you call this function right after calling advance_timestep() then you'll get a result of zero since old_nonlinear_solution is set equal to nonlinear_solution in this function.

Implements libMesh::TimeSolver.

Definition at line 227 of file unsteady_solver.C.

References libMesh::TimeSolver::_system, libMesh::System::calculate_norm(), libMesh::System::get_vector(), and libMesh::System::solution.

{

  std::unique_ptr<NumericVector<Number>> solution_copy =
    _system.solution->clone();

  solution_copy->add(-1., _system.get_vector("_old_nonlinear_solution"));

  solution_copy->close();

  return _system.calculate_norm(*solution_copy, norm);
}

element_residual()

bool libMesh::AdaptiveTimeSolver::element_residual ( bool  get_jacobian, DiffContext &  context  )

overridevirtualinherited

This method is passed on to the core_time_solver

Implements libMesh::TimeSolver.

Definition at line 111 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  libmesh_assert(core_time_solver.get());

  return core_time_solver->element_residual(request_jacobian, context);
}

enable_print_counter_info()

void libMesh::ReferenceCounter::enable_print_counter_info ( )

staticinherited

Methods to enable/disable the reference counter output from print_info()

Definition at line 100 of file reference_counter.C.

References libMesh::ReferenceCounter::_enable_print_counter.

{
  _enable_print_counter = true;
  return;
}

error_order()

Real libMesh::AdaptiveTimeSolver::error_order ( ) const

overridevirtualinherited

This method is passed on to the core_time_solver

Implements libMesh::UnsteadySolver.

Definition at line 102 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  libmesh_assert(core_time_solver.get());

  return core_time_solver->error_order();
}

get_info()

std::string libMesh::ReferenceCounter::get_info ( )

staticinherited

Gets a string containing the reference information.

Definition at line 47 of file reference_counter.C.

References libMesh::ReferenceCounter::_counts, and libMesh::Quality::name().

Referenced by libMesh::ReferenceCounter::print_info().

{
#if defined(LIBMESH_ENABLE_REFERENCE_COUNTING) && defined(DEBUG)

  std::ostringstream oss;

  oss << '\n'
      << " ---------------------------------------------------------------------------- \n"
      << "| Reference count information                                                |\n"
      << " ---------------------------------------------------------------------------- \n";

  for (const auto & pr : _counts)
    {
      const std::string name(pr.first);
      const unsigned int creations    = pr.second.first;
      const unsigned int destructions = pr.second.second;

      oss << "| " << name << " reference count information:\n"
          << "|  Creations:    " << creations    << '\n'
          << "|  Destructions: " << destructions << '\n';
    }

  oss << " ---------------------------------------------------------------------------- \n";

  return oss.str();

#else

  return "";

#endif
}

increment_constructor_count()

void libMesh::ReferenceCounter::increment_constructor_count ( const std::string &  name )

inlineprotectedinherited

Increments the construction counter. Should be called in the constructor of any derived class that will be reference counted.

Definition at line 181 of file reference_counter.h.

References libMesh::ReferenceCounter::_counts, libMesh::Quality::name(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< RBParametrized >::ReferenceCountedObject().

{
  Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
  std::pair<unsigned int, unsigned int> & p = _counts[name];

  p.first++;
}

increment_destructor_count()

void libMesh::ReferenceCounter::increment_destructor_count ( const std::string &  name )

inlineprotectedinherited

Increments the destruction counter. Should be called in the destructor of any derived class that will be reference counted.

Definition at line 194 of file reference_counter.h.

References libMesh::ReferenceCounter::_counts, libMesh::Quality::name(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< RBParametrized >::~ReferenceCountedObject().

{
  Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
  std::pair<unsigned int, unsigned int> & p = _counts[name];

  p.second++;
}

init()

void libMesh::AdaptiveTimeSolver::init ( )

overridevirtualinherited

The initialization function. This method is used to initialize internal data structures before a simulation begins.

Reimplemented from libMesh::UnsteadySolver.

Definition at line 58 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver, and libMesh::UnsteadySolver::old_local_nonlinear_solution.

{
  libmesh_assert(core_time_solver.get());

  // We override this because our core_time_solver is the one that
  // needs to handle new vectors, diff_solver->init(), etc
  core_time_solver->init();

  // As an UnsteadySolver, we have an old_local_nonlinear_solution, but it
  // isn't pointing to the right place - fix it
  //
  // This leaves us with two std::unique_ptrs holding the same pointer - dangerous
  // for future use.  Replace with shared_ptr?
  old_local_nonlinear_solution =
    std::unique_ptr<NumericVector<Number>>(core_time_solver->old_local_nonlinear_solution.get());
}

init_data()

void libMesh::UnsteadySolver::init_data ( )

overridevirtualinherited

The data initialization function. This method is used to initialize internal data structures after the underlying System has been initialized

Reimplemented from libMesh::TimeSolver.

Reimplemented in libMesh::SecondOrderUnsteadySolver.

Definition at line 55 of file unsteady_solver.C.

References libMesh::TimeSolver::_system, libMesh::System::get_dof_map(), libMesh::DofMap::get_send_list(), libMesh::GHOSTED, libMesh::TimeSolver::init_data(), libMesh::System::n_dofs(), libMesh::System::n_local_dofs(), libMesh::UnsteadySolver::old_local_nonlinear_solution, and libMesh::SERIAL.

Referenced by libMesh::SecondOrderUnsteadySolver::init_data().

{
  TimeSolver::init_data();

#ifdef LIBMESH_ENABLE_GHOSTED
  old_local_nonlinear_solution->init (_system.n_dofs(), _system.n_local_dofs(),
                                      _system.get_dof_map().get_send_list(), false,
                                      GHOSTED);
#else
  old_local_nonlinear_solution->init (_system.n_dofs(), false, SERIAL);
#endif
}

is_adjoint()

bool libMesh::TimeSolver::is_adjoint ( ) const

inlineinherited

Accessor for querying whether we need to do a primal or adjoint solve

Definition at line 233 of file time_solver.h.

References libMesh::TimeSolver::_is_adjoint.

Referenced by libMesh::FEMSystem::build_context().

  { return _is_adjoint; }

is_steady()

virtual bool libMesh::UnsteadySolver::is_steady ( ) const

inlineoverridevirtualinherited

This is not a steady-state solver.

Implements libMesh::TimeSolver.

Definition at line 154 of file unsteady_solver.h.

{ return false; }

linear_solver()

std::unique_ptr< LinearSolver< Number > > & libMesh::AdaptiveTimeSolver::linear_solver ( )

overridevirtualinherited

An implicit linear solver to use for adjoint and sensitivity problems.

Reimplemented from libMesh::TimeSolver.

Definition at line 148 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  return core_time_solver->linear_solver();
}

n_objects()

static unsigned int libMesh::ReferenceCounter::n_objects ( )

inlinestaticinherited

Prints the number of outstanding (created, but not yet destroyed) objects.

Definition at line 83 of file reference_counter.h.

References libMesh::ReferenceCounter::_n_objects.

  { return _n_objects; }

nonlocal_residual()

bool libMesh::AdaptiveTimeSolver::nonlocal_residual ( bool  get_jacobian, DiffContext &  context  )

overridevirtualinherited

This method is passed on to the core_time_solver

Implements libMesh::TimeSolver.

Definition at line 131 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  libmesh_assert(core_time_solver.get());

  return core_time_solver->nonlocal_residual(request_jacobian, context);
}

old_nonlinear_solution()

Number libMesh::UnsteadySolver::old_nonlinear_solution ( const dof_id_type  global_dof_number ) const

inherited

Returns

The old nonlinear solution for the specified global DOF.

Definition at line 216 of file unsteady_solver.C.

References libMesh::TimeSolver::_system, libMesh::System::get_dof_map(), libMesh::DofMap::n_dofs(), and libMesh::UnsteadySolver::old_local_nonlinear_solution.

Referenced by libMesh::EulerSolver::_general_residual(), libMesh::Euler2Solver::_general_residual(), and libMesh::NewmarkSolver::_general_residual().

{
  libmesh_assert_less (global_dof_number, _system.get_dof_map().n_dofs());
  libmesh_assert_less (global_dof_number, old_local_nonlinear_solution->size());

  return (*old_local_nonlinear_solution)(global_dof_number);
}

prepare_accel()

void libMesh::FirstOrderUnsteadySolver::prepare_accel ( DiffContext &  context )

protectedinherited

If there are second order variables in the system, then we also prepare the accel for those variables so the user can treat them as such.

Definition at line 25 of file first_order_unsteady_solver.C.

References libMesh::DiffContext::elem_solution_accel_derivative, libMesh::DiffContext::get_elem_solution_accel(), libMesh::DiffContext::get_elem_solution_rate(), and libMesh::DiffContext::get_elem_solution_rate_derivative().

Referenced by libMesh::EulerSolver::_general_residual(), and libMesh::Euler2Solver::_general_residual().

{
  context.get_elem_solution_accel() = context.get_elem_solution_rate();

  context.elem_solution_accel_derivative = context.get_elem_solution_rate_derivative();
}

print_info()

void libMesh::ReferenceCounter::print_info ( std::ostream &  out = libMesh::out )

staticinherited

Prints the reference information, by default to libMesh::out.

Definition at line 87 of file reference_counter.C.

References libMesh::ReferenceCounter::_enable_print_counter, and libMesh::ReferenceCounter::get_info().

{
  if (_enable_print_counter)
    out_stream << ReferenceCounter::get_info();
}

reinit()

void libMesh::AdaptiveTimeSolver::reinit ( )

overridevirtualinherited

The reinitialization function. This method is used to resize internal data vectors after a mesh change.

Reimplemented from libMesh::UnsteadySolver.

Definition at line 77 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  libmesh_assert(core_time_solver.get());

  // We override this because our core_time_solver is the one that
  // needs to handle new vectors, diff_solver->reinit(), etc
  core_time_solver->reinit();
}

retrieve_timestep()

void libMesh::UnsteadySolver::retrieve_timestep ( )

overridevirtualinherited

This method retrieves all the stored solutions at the current system.time

Reimplemented from libMesh::TimeSolver.

Reimplemented in libMesh::SecondOrderUnsteadySolver.

Definition at line 204 of file unsteady_solver.C.

References libMesh::TimeSolver::_system, libMesh::System::get_dof_map(), libMesh::DofMap::get_send_list(), libMesh::System::get_vector(), libMesh::NumericVector< T >::localize(), libMesh::UnsteadySolver::old_local_nonlinear_solution, and libMesh::TimeSolver::solution_history.

{
  // Retrieve all the stored vectors at the current time
  solution_history->retrieve();

  // Dont forget to localize the old_nonlinear_solution !
  _system.get_vector("_old_nonlinear_solution").localize
    (*old_local_nonlinear_solution,
     _system.get_dof_map().get_send_list());
}

set_is_adjoint()

void libMesh::TimeSolver::set_is_adjoint ( bool  _is_adjoint_value )

inlineinherited

Accessor for setting whether we need to do a primal or adjoint solve

Definition at line 240 of file time_solver.h.

References libMesh::TimeSolver::_is_adjoint.

Referenced by libMesh::DifferentiableSystem::adjoint_solve(), libMesh::FEMSystem::postprocess(), and libMesh::DifferentiableSystem::solve().

  { _is_adjoint = _is_adjoint_value; }

set_solution_history()

void libMesh::TimeSolver::set_solution_history ( const SolutionHistory &  _solution_history )

inherited

A setter function users will employ if they need to do something other than save no solution history

Definition at line 97 of file time_solver.C.

References libMesh::SolutionHistory::clone(), and libMesh::TimeSolver::solution_history.

{
  solution_history = _solution_history.clone();
}

side_residual()

bool libMesh::AdaptiveTimeSolver::side_residual ( bool  get_jacobian, DiffContext &  context  )

overridevirtualinherited

This method is passed on to the core_time_solver

Implements libMesh::TimeSolver.

Definition at line 121 of file adaptive_time_solver.C.

References libMesh::AdaptiveTimeSolver::core_time_solver.

{
  libmesh_assert(core_time_solver.get());

  return core_time_solver->side_residual(request_jacobian, context);
}

solve()

void libMesh::TwostepTimeSolver::solve ( )

overridevirtual

This method solves for the solution at the next timestep. Usually we will only need to solve one (non)linear system per timestep, but more complex subclasses may override this.

Implements libMesh::AdaptiveTimeSolver.

Definition at line 45 of file twostep_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::AdaptiveTimeSolver::calculate_norm(), libMesh::NumericVector< T >::clone(), libMesh::AdaptiveTimeSolver::core_time_solver, libMesh::DifferentiableSystem::deltat, libMesh::UnsteadySolver::first_solve, libMesh::System::get_vector(), libMesh::AdaptiveTimeSolver::global_tolerance, libMesh::AdaptiveTimeSolver::last_deltat, std::max(), libMesh::AdaptiveTimeSolver::max_deltat, libMesh::AdaptiveTimeSolver::max_growth, libMesh::AdaptiveTimeSolver::min_deltat, libMesh::out, std::pow(), libMesh::TimeSolver::quiet, libMesh::Real, libMesh::TimeSolver::reduce_deltat_on_diffsolver_failure, libMesh::System::solution, libMesh::AdaptiveTimeSolver::target_tolerance, libMesh::System::time, and libMesh::AdaptiveTimeSolver::upper_tolerance.

{
  libmesh_assert(core_time_solver.get());

  // The core_time_solver will handle any first_solve actions
  first_solve = false;

  // We may have to repeat timesteps entirely if our error is bad
  // enough
  bool max_tolerance_met = false;

  // Calculating error values each time
  Real single_norm(0.), double_norm(0.), error_norm(0.),
    relative_error(0.);

  while (!max_tolerance_met)
    {
      // If we've been asked to reduce deltat if necessary, make sure
      // the core timesolver does so
      core_time_solver->reduce_deltat_on_diffsolver_failure =
        this->reduce_deltat_on_diffsolver_failure;

      if (!quiet)
        {
          libMesh::out << "\n === Computing adaptive timestep === "
                       << std::endl;
        }

      // Use the double-length timestep first (so the
      // old_nonlinear_solution won't have to change)
      core_time_solver->solve();

      // Save a copy of the double-length nonlinear solution
      // and the old nonlinear solution
      std::unique_ptr<NumericVector<Number>> double_solution =
        _system.solution->clone();
      std::unique_ptr<NumericVector<Number>> old_solution =
        _system.get_vector("_old_nonlinear_solution").clone();

      double_norm = calculate_norm(_system, *double_solution);
      if (!quiet)
        {
          libMesh::out << "Double norm = " << double_norm << std::endl;
        }

      // Then reset the initial guess for our single-length calcs
      *(_system.solution) = _system.get_vector("_old_nonlinear_solution");

      // Call two single-length timesteps
      // Be sure that the core_time_solver does not change the
      // timestep here.  (This is unlikely because it just succeeded
      // with a timestep twice as large!)
      // FIXME: even if diffsolver failure is unlikely, we ought to
      // do *something* if it happens
      core_time_solver->reduce_deltat_on_diffsolver_failure = 0;

      Real old_time = _system.time;
      Real old_deltat = _system.deltat;
      _system.deltat *= 0.5;
      core_time_solver->solve();
      core_time_solver->advance_timestep();
      core_time_solver->solve();

      single_norm = calculate_norm(_system, *_system.solution);
      if (!quiet)
        {
          libMesh::out << "Single norm = " << single_norm << std::endl;
        }

      // Reset the core_time_solver's reduce_deltat... value.
      core_time_solver->reduce_deltat_on_diffsolver_failure =
        this->reduce_deltat_on_diffsolver_failure;

      // But then back off just in case our advance_timestep() isn't
      // called.
      // FIXME: this probably doesn't work with multistep methods
      _system.get_vector("_old_nonlinear_solution") = *old_solution;
      _system.time = old_time;
      _system.deltat = old_deltat;

      // Find the relative error
      *double_solution -= *(_system.solution);
      error_norm  = calculate_norm(_system, *double_solution);
      relative_error = error_norm / _system.deltat /
        std::max(double_norm, single_norm);

      // If the relative error makes no sense, we're done
      if (!double_norm && !single_norm)
        return;

      if (!quiet)
        {
          libMesh::out << "Error norm = " << error_norm << std::endl;
          libMesh::out << "Local relative error = "
                       << (error_norm /
                           std::max(double_norm, single_norm))
                       << std::endl;
          libMesh::out << "Global relative error = "
                       << (error_norm / _system.deltat /
                           std::max(double_norm, single_norm))
                       << std::endl;
          libMesh::out << "old delta t = " << _system.deltat << std::endl;
        }

      // If our upper tolerance is negative, that means we want to set
      // it based on the first successful time step
      if (this->upper_tolerance < 0)
        this->upper_tolerance = -this->upper_tolerance * relative_error;

      // If we haven't met our upper error tolerance, we'll have to
      // repeat this timestep entirely
      if (this->upper_tolerance && relative_error > this->upper_tolerance)
        {
          // Reset the initial guess for our next try
          *(_system.solution) =
            _system.get_vector("_old_nonlinear_solution");

          // Chop delta t in half
          _system.deltat /= 2.;

          if (!quiet)
            {
              libMesh::out << "Failed to meet upper error tolerance"
                           << std::endl;
              libMesh::out << "Retrying with delta t = "
                           << _system.deltat << std::endl;
            }
        }
      else
        max_tolerance_met = true;
    }


  // Otherwise, compare the relative error to the tolerance
  // and adjust deltat
  last_deltat = _system.deltat;

  // If our target tolerance is negative, that means we want to set
  // it based on the first successful time step
  if (this->target_tolerance < 0)
    this->target_tolerance = -this->target_tolerance * relative_error;

  const Real global_shrink_or_growth_factor =
    std::pow(this->target_tolerance / relative_error,
             static_cast<Real>(1. / core_time_solver->error_order()));

  const Real local_shrink_or_growth_factor =
    std::pow(this->target_tolerance /
             (error_norm/std::max(double_norm, single_norm)),
             static_cast<Real>(1. / (core_time_solver->error_order()+1.)));

  if (!quiet)
    {
      libMesh::out << "The global growth/shrink factor is: "
                   << global_shrink_or_growth_factor << std::endl;
      libMesh::out << "The local growth/shrink factor is: "
                   << local_shrink_or_growth_factor << std::endl;
    }

  // The local s.o.g. factor is based on the expected **local**
  // truncation error for the timestepping method, the global
  // s.o.g. factor is based on the method's **global** truncation
  // error.  You can shrink/grow the timestep to attempt to satisfy
  // either a global or local time-discretization error tolerance.

  Real shrink_or_growth_factor =
    this->global_tolerance ? global_shrink_or_growth_factor :
    local_shrink_or_growth_factor;

  if (this->max_growth && this->max_growth < shrink_or_growth_factor)
    {
      if (!quiet && this->global_tolerance)
        {
          libMesh::out << "delta t is constrained by max_growth" << std::endl;
        }
      shrink_or_growth_factor = this->max_growth;
    }

  _system.deltat *= shrink_or_growth_factor;

  // Restrict deltat to max-allowable value if necessary
  if ((this->max_deltat != 0.0) && (_system.deltat > this->max_deltat))
    {
      if (!quiet)
        {
          libMesh::out << "delta t is constrained by maximum-allowable delta t."
                       << std::endl;
        }
      _system.deltat = this->max_deltat;
    }

  // Restrict deltat to min-allowable value if necessary
  if ((this->min_deltat != 0.0) && (_system.deltat < this->min_deltat))
    {
      if (!quiet)
        {
          libMesh::out << "delta t is constrained by minimum-allowable delta t."
                       << std::endl;
        }
      _system.deltat = this->min_deltat;
    }

  if (!quiet)
    {
      libMesh::out << "new delta t = " << _system.deltat << std::endl;
    }
}

system() [1/2]

const sys_type& libMesh::TimeSolver::system ( ) const

inlineinherited

Returns

A constant reference to the system we are solving.

Definition at line 172 of file time_solver.h.

References libMesh::TimeSolver::_system.

Referenced by libMesh::TimeSolver::reinit(), and libMesh::TimeSolver::solve().

{ return _system; }

system() [2/2]

sys_type& libMesh::TimeSolver::system ( )

inlineinherited

Returns

A writable reference to the system we are solving.

Definition at line 177 of file time_solver.h.

References libMesh::TimeSolver::_system.

{ return _system; }

time_order()

virtual unsigned int libMesh::FirstOrderUnsteadySolver::time_order ( ) const

inlineoverridevirtualinherited

Returns

The maximum order of time derivatives for which the UnsteadySolver subclass is capable of handling.

For example, EulerSolver will have time_order() = 1 and NewmarkSolver will have time_order() = 2.

Implements libMesh::UnsteadySolver.

Definition at line 90 of file first_order_unsteady_solver.h.

  { return 1; }

Member Data Documentation

_counts

ReferenceCounter::Counts libMesh::ReferenceCounter::_counts

staticprotectedinherited

Actually holds the data.

Definition at line 122 of file reference_counter.h.

Referenced by libMesh::ReferenceCounter::get_info(), libMesh::ReferenceCounter::increment_constructor_count(), and libMesh::ReferenceCounter::increment_destructor_count().

_diff_solver

std::unique_ptr<DiffSolver> libMesh::TimeSolver::_diff_solver

protectedinherited

An implicit linear or nonlinear solver to use at each timestep.

Definition at line 248 of file time_solver.h.

Referenced by libMesh::NewmarkSolver::compute_initial_accel(), libMesh::TimeSolver::diff_solver(), and libMesh::UnsteadySolver::solve().

_enable_print_counter

bool libMesh::ReferenceCounter::_enable_print_counter = true

staticprotectedinherited

Flag to control whether reference count information is printed when print_info is called.

Definition at line 141 of file reference_counter.h.

Referenced by libMesh::ReferenceCounter::disable_print_counter_info(), libMesh::ReferenceCounter::enable_print_counter_info(), and libMesh::ReferenceCounter::print_info().

_linear_solver

std::unique_ptr<LinearSolver<Number> > libMesh::TimeSolver::_linear_solver

protectedinherited

An implicit linear solver to use for adjoint problems.

Definition at line 253 of file time_solver.h.

Referenced by libMesh::TimeSolver::linear_solver().

_mutex

Threads::spin_mutex libMesh::ReferenceCounter::_mutex

staticprotectedinherited

Mutual exclusion object to enable thread-safe reference counting.

Definition at line 135 of file reference_counter.h.

_n_objects

Threads::atomic< unsigned int > libMesh::ReferenceCounter::_n_objects

staticprotectedinherited

The number of objects. Print the reference count information when the number returns to 0.

Definition at line 130 of file reference_counter.h.

Referenced by libMesh::ReferenceCounter::n_objects(), libMesh::ReferenceCounter::ReferenceCounter(), and libMesh::ReferenceCounter::~ReferenceCounter().

_system

sys_type& libMesh::TimeSolver::_system

protectedinherited

A reference to the system we are solving.

Definition at line 258 of file time_solver.h.

Referenced by libMesh::EulerSolver::_general_residual(), libMesh::Euler2Solver::_general_residual(), libMesh::SteadySolver::_general_residual(), libMesh::NewmarkSolver::_general_residual(), libMesh::UnsteadySolver::adjoint_advance_timestep(), libMesh::NewmarkSolver::advance_timestep(), libMesh::AdaptiveTimeSolver::advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), libMesh::NewmarkSolver::compute_initial_accel(), libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns(), libMesh::UnsteadySolver::du(), libMesh::EulerSolver::element_residual(), libMesh::Euler2Solver::element_residual(), libMesh::EigenTimeSolver::element_residual(), libMesh::SecondOrderUnsteadySolver::init(), libMesh::UnsteadySolver::init(), libMesh::TimeSolver::init(), libMesh::EigenTimeSolver::init(), libMesh::SecondOrderUnsteadySolver::init_data(), libMesh::UnsteadySolver::init_data(), libMesh::TimeSolver::init_data(), libMesh::EulerSolver::nonlocal_residual(), libMesh::Euler2Solver::nonlocal_residual(), libMesh::EigenTimeSolver::nonlocal_residual(), libMesh::UnsteadySolver::old_nonlinear_solution(), libMesh::SecondOrderUnsteadySolver::old_solution_accel(), libMesh::SecondOrderUnsteadySolver::old_solution_rate(), libMesh::NewmarkSolver::project_initial_accel(), libMesh::SecondOrderUnsteadySolver::project_initial_rate(), libMesh::SecondOrderUnsteadySolver::reinit(), libMesh::UnsteadySolver::reinit(), libMesh::TimeSolver::reinit(), libMesh::UnsteadySolver::retrieve_timestep(), libMesh::EigenTimeSolver::side_residual(), solve(), libMesh::UnsteadySolver::solve(), libMesh::EigenTimeSolver::solve(), and libMesh::TimeSolver::system().

component_norm

SystemNorm libMesh::AdaptiveTimeSolver::component_norm

inherited

Error calculations are done in this norm, DISCRETE_L2 by default.

Definition at line 119 of file adaptive_time_solver.h.

Referenced by libMesh::AdaptiveTimeSolver::calculate_norm().

component_scale

std::vector<float> libMesh::AdaptiveTimeSolver::component_scale

inherited

If component_norms is non-empty, each variable's contribution to the error of a system will also be scaled by component_scale[var], unless component_scale is empty in which case all variables will be weighted equally.

Definition at line 127 of file adaptive_time_solver.h.

core_time_solver

std::unique_ptr<UnsteadySolver> libMesh::AdaptiveTimeSolver::core_time_solver

inherited

This object is used to take timesteps

Definition at line 114 of file adaptive_time_solver.h.

Referenced by libMesh::AdaptiveTimeSolver::diff_solver(), libMesh::AdaptiveTimeSolver::element_residual(), libMesh::AdaptiveTimeSolver::error_order(), libMesh::AdaptiveTimeSolver::init(), libMesh::AdaptiveTimeSolver::linear_solver(), libMesh::AdaptiveTimeSolver::nonlocal_residual(), libMesh::AdaptiveTimeSolver::reinit(), libMesh::AdaptiveTimeSolver::side_residual(), solve(), and TwostepTimeSolver().

first_adjoint_step

bool libMesh::UnsteadySolver::first_adjoint_step

protectedinherited

A bool that will be true the first time adjoint_advance_timestep() is called, (when the primal solution is to be used to set adjoint boundary conditions) and false thereafter

Definition at line 168 of file unsteady_solver.h.

Referenced by libMesh::UnsteadySolver::adjoint_advance_timestep().

first_solve

bool libMesh::UnsteadySolver::first_solve

protectedinherited

A bool that will be true the first time solve() is called, and false thereafter

Definition at line 162 of file unsteady_solver.h.

Referenced by libMesh::NewmarkSolver::advance_timestep(), libMesh::AdaptiveTimeSolver::advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), solve(), and libMesh::UnsteadySolver::solve().

global_tolerance

bool libMesh::AdaptiveTimeSolver::global_tolerance

inherited

This flag, which is true by default, grows (shrinks) the timestep based on the expected global accuracy of the timestepping scheme. Global in this sense means the cumulative final-time accuracy of the scheme. For example, the backward Euler scheme's truncation error is locally of order 2, so that after N timesteps of size deltat, the result is first-order accurate. If you set this to false, you can grow (shrink) your timestep based on the local accuracy rather than the global accuracy of the core TimeSolver.

Note

By setting this value to false you may fail to achieve the predicted convergence in time of the underlying method, however it may be possible to get more fine-grained control over step sizes as well.

Definition at line 198 of file adaptive_time_solver.h.

Referenced by solve().

last_deltat

Real libMesh::AdaptiveTimeSolver::last_deltat

protectedinherited

We need to store the value of the last deltat used, so that advance_timestep() will increment the system time correctly.

Definition at line 207 of file adaptive_time_solver.h.

Referenced by libMesh::AdaptiveTimeSolver::advance_timestep(), and solve().

max_deltat

Real libMesh::AdaptiveTimeSolver::max_deltat

inherited

Do not allow the adaptive time solver to select deltat > max_deltat. If you use the default max_deltat=0.0, then deltat is unlimited.

Definition at line 167 of file adaptive_time_solver.h.

Referenced by solve().

max_growth

Real libMesh::AdaptiveTimeSolver::max_growth

inherited

Do not allow the adaptive time solver to select a new deltat greater than max_growth times the old deltat. If you use the default max_growth=0.0, then the deltat growth is unlimited.

Definition at line 181 of file adaptive_time_solver.h.

Referenced by solve().

min_deltat

Real libMesh::AdaptiveTimeSolver::min_deltat

inherited

Do not allow the adaptive time solver to select deltat < min_deltat. The default value is 0.0.

Definition at line 173 of file adaptive_time_solver.h.

Referenced by solve().

old_local_nonlinear_solution

std::unique_ptr<NumericVector<Number> > libMesh::UnsteadySolver::old_local_nonlinear_solution

inherited

Serial vector of _system.get_vector("_old_nonlinear_solution")

Definition at line 138 of file unsteady_solver.h.

Referenced by libMesh::AdaptiveTimeSolver::AdaptiveTimeSolver(), libMesh::UnsteadySolver::adjoint_advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), libMesh::AdaptiveTimeSolver::init(), libMesh::UnsteadySolver::init_data(), libMesh::UnsteadySolver::old_nonlinear_solution(), libMesh::UnsteadySolver::reinit(), libMesh::UnsteadySolver::retrieve_timestep(), and libMesh::AdaptiveTimeSolver::~AdaptiveTimeSolver().

quiet

bool libMesh::TimeSolver::quiet

inherited

Print extra debugging information if quiet == false.

Definition at line 192 of file time_solver.h.

Referenced by solve(), libMesh::UnsteadySolver::solve(), and libMesh::EigenTimeSolver::solve().

reduce_deltat_on_diffsolver_failure

unsigned int libMesh::TimeSolver::reduce_deltat_on_diffsolver_failure

inherited

This value (which defaults to zero) is the number of times the TimeSolver is allowed to halve deltat and let the DiffSolver repeat the latest failed solve with a reduced timestep.

Note

This has no effect for SteadySolvers.

You must set at least one of the DiffSolver flags "continue_after_max_iterations" or "continue_after_backtrack_failure" to allow the TimeSolver to retry the solve.

Definition at line 221 of file time_solver.h.

Referenced by solve(), and libMesh::UnsteadySolver::solve().

solution_history

std::unique_ptr<SolutionHistory> libMesh::TimeSolver::solution_history

protectedinherited

A std::unique_ptr to a SolutionHistory object. Default is NoSolutionHistory, which the user can override by declaring a different kind of SolutionHistory in the application

Definition at line 265 of file time_solver.h.

Referenced by libMesh::UnsteadySolver::adjoint_advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), libMesh::UnsteadySolver::retrieve_timestep(), and libMesh::TimeSolver::set_solution_history().

target_tolerance

Real libMesh::AdaptiveTimeSolver::target_tolerance

inherited

This tolerance is the target relative error between an exact time integration and a single time step output, scaled by deltat. integrator, scaled by deltat. If the estimated error exceeds or undershoots the target error tolerance, future timesteps will be run with deltat shrunk or grown to compensate.

The default value is 1.0e-2; obviously users should select their own tolerance.

If a negative target_tolerance is specified, then its absolute value is used to scale the estimated error from the first simulation time step, and this becomes the target tolerance of all future time steps.

Definition at line 144 of file adaptive_time_solver.h.

Referenced by solve().

upper_tolerance

Real libMesh::AdaptiveTimeSolver::upper_tolerance

inherited

This tolerance is the maximum relative error between an exact time integration and a single time step output, scaled by deltat. If this error tolerance is exceeded by the estimated error of the current time step, that time step will be repeated with a smaller deltat.

If you use the default upper_tolerance=0.0, then the current time step will not be repeated regardless of estimated error.

If a negative upper_tolerance is specified, then its absolute value is used to scale the estimated error from the first simulation time step, and this becomes the upper tolerance of all future time steps.

Definition at line 161 of file adaptive_time_solver.h.

Referenced by solve().

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

• twostep_time_solver.h
• twostep_time_solver.C