libMesh::FirstOrderUnsteadySolver Class Reference

Generic class from which first order UnsteadySolvers should subclass. More...

#include <first_order_unsteady_solver.h>

Inheritance diagram for libMesh::FirstOrderUnsteadySolver:

Public Types
typedef DifferentiableSystem	sys_type
	The type of system. More...

Public Member Functions
	FirstOrderUnsteadySolver (sys_type &s)
	Constructor. More...
virtual	~FirstOrderUnsteadySolver ()
	Destructor. More...
virtual unsigned int	time_order () const override
virtual void	init () override
	The initialization function. More...
virtual void	init_data () override
	The data initialization function. More...
virtual void	reinit () override
	The reinitialization function. More...
virtual void	solve () override
	This method solves for the solution at the next timestep. More...
virtual void	advance_timestep () override
	This method advances the solution to the next timestep, after a solve() has been performed. More...
virtual void	adjoint_advance_timestep () override
	This method advances the adjoint solution to the previous timestep, after an adjoint_solve() has been performed. More...
virtual void	retrieve_timestep () override
	This method retrieves all the stored solutions at the current system.time. More...
virtual Real	error_order () const =0
	This method should return the expected convergence order of the (non-local) error of the time discretization scheme - e.g. More...
Number	old_nonlinear_solution (const dof_id_type global_dof_number) const
virtual Real	du (const SystemNorm &norm) const override
	Computes the size of ||u^{n+1} - u^{n}|| in some norm. More...
virtual bool	is_steady () const override
	This is not a steady-state solver. More...
virtual bool	element_residual (bool request_jacobian, DiffContext &)=0
	This method uses the DifferentiablePhysics element_time_derivative(), element_constraint(), and mass_residual() to build a full residual on an element. More...
virtual bool	side_residual (bool request_jacobian, DiffContext &)=0
	This method uses the DifferentiablePhysics side_time_derivative(), side_constraint(), and side_mass_residual() to build a full residual on an element's side. More...
virtual bool	nonlocal_residual (bool request_jacobian, DiffContext &)=0
	This method uses the DifferentiablePhysics nonlocal_time_derivative(), nonlocal_constraint(), and nonlocal_mass_residual() to build a full residual of non-local terms. More...
virtual void	before_timestep ()
	This method is for subclasses or users to override to do arbitrary processing between timesteps. More...
const sys_type &	system () const
sys_type &	system ()
virtual std::unique_ptr< DiffSolver > &	diff_solver ()
	An implicit linear or nonlinear solver to use at each timestep. More...
virtual std::unique_ptr< LinearSolver< Number > > &	linear_solver ()
	An implicit linear solver to use for adjoint and sensitivity problems. More...
void	set_solution_history (const SolutionHistory &_solution_history)
	A setter function users will employ if they need to do something other than save no solution history. More...
bool	is_adjoint () const
	Accessor for querying whether we need to do a primal or adjoint solve. More...
void	set_is_adjoint (bool _is_adjoint_value)
	Accessor for setting whether we need to do a primal or adjoint solve. More...

Static Public Member Functions
static std::string	get_info ()
	Gets a string containing the reference information. More...
static void	print_info (std::ostream &out=libMesh::out)
	Prints the reference information, by default to libMesh::out. More...
static unsigned int	n_objects ()
	Prints the number of outstanding (created, but not yet destroyed) objects. More...
static void	enable_print_counter_info ()
	Methods to enable/disable the reference counter output from print_info() More...
static void	disable_print_counter_info ()

Public Attributes
std::unique_ptr< NumericVector< Number > >	old_local_nonlinear_solution
	Serial vector of _system.get_vector("_old_nonlinear_solution") More...
bool	quiet
	Print extra debugging information if quiet == false. More...
unsigned int	reduce_deltat_on_diffsolver_failure
	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. More...

Protected Types
typedef bool(DifferentiablePhysics::*	ResFuncType) (bool, DiffContext &)
	Definitions of argument types for use in refactoring subclasses. More...
typedef void(DiffContext::*	ReinitFuncType) (Real)
typedef std::map< std::string, std::pair< unsigned int, unsigned int > >	Counts
	Data structure to log the information. More...

Protected Member Functions
void	prepare_accel (DiffContext &context)
	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. More...
bool	compute_second_order_eqns (bool compute_jacobian, DiffContext &c)
	If there are second order variables, then we need to compute their residual equations and corresponding Jacobian. More...
void	increment_constructor_count (const std::string &name)
	Increments the construction counter. More...
void	increment_destructor_count (const std::string &name)
	Increments the destruction counter. More...

Protected Attributes
bool	first_solve
	A bool that will be true the first time solve() is called, and false thereafter. More...
bool	first_adjoint_step
	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. More...
std::unique_ptr< DiffSolver >	_diff_solver
	An implicit linear or nonlinear solver to use at each timestep. More...
std::unique_ptr< LinearSolver< Number > >	_linear_solver
	An implicit linear solver to use for adjoint problems. More...
sys_type &	_system
	A reference to the system we are solving. More...
std::unique_ptr< SolutionHistory >	solution_history
	A std::unique_ptr to a SolutionHistory object. More...

Static Protected Attributes
static Counts	_counts
	Actually holds the data. More...
static Threads::atomic< unsigned int >	_n_objects
	The number of objects. More...
static Threads::spin_mutex	_mutex
	Mutual exclusion object to enable thread-safe reference counting. More...
static bool	_enable_print_counter = true
	Flag to control whether reference count information is printed when print_info is called. More...

Private Attributes
bool	_is_adjoint
	This boolean tells the TimeSolver whether we are solving a primal or adjoint problem. More...

Detailed Description

Generic class from which first order UnsteadySolvers should subclass.

Subclasses of this class are meant to solve problems of the form

\[ M(u)\dot{u} = F(u)\]

There is also infrastructure for subclasses to support solving second order-in-time systems (or both first order and second order). In particular, consider the second system

\[ M(u)\ddot{u} + C(u)\dot{u} + F(u) = 0 \]

If we introduce the equation \(\dot{u} = v\), then, we have the following first order system:

\begin{eqnarray} \dot{u} &=& v \\ M(u)\dot{v} + C(u)v + F(u) &=& 0\end{eqnarray}

Such systems are supported by the user specifying that the time order of the variable \(u\) is 2 when adding the variable using FEMSystem::time_evolving. This class will then add the \(v\) variables to the FEMSystem (named "dot_u" if the second order variable name is "u"). Subclasses will then need to make sure to use the function FirstOrderUnsteadySolver::prepare_accel() to prepare data structures for the users to use from FEMContext. Furthermore, subclasses will need to appropriately call damping_residual functions. Finally, subclasses will call FirstOrderUnsteadySolver::compute_second_order_eqns() to actually assemble residual and Jacobians for the \( \dot{u} = v\) equations. These aspects should be invisible ot users during their element assembly.

Unfortunately, complete usage of the feature of treating second order equations as a system of first order equations is not completely invisible to the user. The user must assemble their residual in the correct equation. In particular, the residual must go in the \(v\) residual equation, i.e. \( M(u)\dot{v} + C(u)v + F(u) = 0 \), and, subsequently, they must also be careful to populate to the correct Jacobian blocks. The function to help facilitate this is get_second_order_dot_var. If you have a second order variable, you pass that variable index and get_second_order_dot_var will return the index of the corresponding velocity variable, \(v\) in the notation above. Then, the user knows what blocks to populate.

Note

The API is designed so that if the user codes to this paradigm, the TimeSolver will be interchangeable for those element kernels. That is, they'll be able to use either a FirstOrderUnsteadySolver or a SecondOrderUnsteadySolver.

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

Paul T. Bauman

Date

2015

Definition at line 74 of file first_order_unsteady_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.

ReinitFuncType

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

protectedinherited

Definition at line 272 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 270 of file time_solver.h.

sys_type

typedef DifferentiableSystem libMesh::TimeSolver::sys_type

inherited

The type of system.

Definition at line 64 of file time_solver.h.

Constructor & Destructor Documentation

FirstOrderUnsteadySolver()

libMesh::FirstOrderUnsteadySolver::FirstOrderUnsteadySolver ( sys_type &  s )

inlineexplicit

Constructor.

Requires a reference to the system to be solved.

Definition at line 82 of file first_order_unsteady_solver.h.

    : UnsteadySolver(s) {}

~FirstOrderUnsteadySolver()

virtual libMesh::FirstOrderUnsteadySolver::~FirstOrderUnsteadySolver ( )

inlinevirtual

Destructor.

Definition at line 88 of file first_order_unsteady_solver.h.

{}

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.

{
  // 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());
}

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.

advance_timestep()

void libMesh::UnsteadySolver::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::TimeSolver.

Reimplemented in libMesh::AdaptiveTimeSolver, and libMesh::NewmarkSolver.

Definition at line 152 of file unsteady_solver.C.

{
  if (!first_solve)
    {
      // Store the solution, does nothing by default
      // User has to attach appropriate solution_history object for this to
      // actually store anything anywhere
      solution_history->store();
 
      _system.time += _system.deltat;
    }
 
  NumericVector<Number> & old_nonlinear_soln =
    _system.get_vector("_old_nonlinear_solution");
  NumericVector<Number> & nonlinear_solution =
    *(_system.solution);
 
  old_nonlinear_soln = nonlinear_solution;
 
  old_nonlinear_soln.localize
    (*old_local_nonlinear_solution,
     _system.get_dof_map().get_send_list());
}

References libMesh::TimeSolver::_system, libMesh::DifferentiableSystem::deltat, libMesh::UnsteadySolver::first_solve, 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::System::solution, libMesh::TimeSolver::solution_history, and libMesh::System::time.

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

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 166 of file time_solver.h.

{}

compute_second_order_eqns()

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

protected

If there are second order variables, then we need to compute their residual equations and corresponding Jacobian.

The residual equation will simply be \( \dot{u} - v = 0 \), where \( u \) is the second order variable add by the user and \( v \) is the variable added by the time-solver as the "velocity" variable.

Definition at line 32 of file first_order_unsteady_solver.C.

{
  FEMContext & context = cast_ref<FEMContext &>(c);
 
  unsigned int n_qpoints = context.get_element_qrule().n_points();
 
  for (auto var : IntRange<unsigned int>(0, context.n_vars()))
    {
      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;
}

References libMesh::TimeSolver::_system, compute_jacobian(), 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::libmesh_assert(), 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().

diff_solver()

virtual std::unique_ptr<DiffSolver>& libMesh::TimeSolver::diff_solver ( )

inlinevirtualinherited

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

Reimplemented in libMesh::AdaptiveTimeSolver.

Definition at line 181 of file time_solver.h.

{ return _diff_solver; }

References libMesh::TimeSolver::_diff_solver.

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

disable_print_counter_info()

void libMesh::ReferenceCounter::disable_print_counter_info ( )

staticinherited

Definition at line 106 of file reference_counter.C.

{
  _enable_print_counter = false;
  return;
}

References libMesh::ReferenceCounter::_enable_print_counter.

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

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.

{
 
  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);
}

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

element_residual()

virtual bool libMesh::TimeSolver::element_residual ( bool  request_jacobian, DiffContext &    )

pure virtualinherited

This method uses the DifferentiablePhysics element_time_derivative(), element_constraint(), and mass_residual() to build a full residual on an element.

What combination

it uses will depend on the type of solver. See the subclasses for more details.

Implemented in libMesh::NewmarkSolver, libMesh::SteadySolver, libMesh::Euler2Solver, libMesh::EulerSolver, libMesh::EigenTimeSolver, and libMesh::AdaptiveTimeSolver.

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

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.

{
  _enable_print_counter = true;
  return;
}

References libMesh::ReferenceCounter::_enable_print_counter.

error_order()

virtual Real libMesh::UnsteadySolver::error_order ( ) const

pure virtualinherited

This method should return the expected convergence order of the (non-local) error of the time discretization scheme - e.g.

2 for the O(deltat^2) Crank-Nicholson, or 1 for the O(deltat) Backward Euler.

Useful for adaptive timestepping schemes.

Implemented in libMesh::NewmarkSolver, libMesh::AdaptiveTimeSolver, libMesh::Euler2Solver, and libMesh::EulerSolver.

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.

{
#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
}

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

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

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.

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

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

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

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.

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

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

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

init()

void libMesh::UnsteadySolver::init ( )

overridevirtualinherited

The initialization function.

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

Reimplemented from libMesh::TimeSolver.

Reimplemented in libMesh::AdaptiveTimeSolver, and libMesh::SecondOrderUnsteadySolver.

Definition at line 46 of file unsteady_solver.C.

{
  TimeSolver::init();
 
  _system.add_vector("_old_nonlinear_solution");
}

References libMesh::TimeSolver::_system, libMesh::System::add_vector(), and libMesh::TimeSolver::init().

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

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.

{
  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
}

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().

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 232 of file time_solver.h.

  { return _is_adjoint; }

References libMesh::TimeSolver::_is_adjoint.

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

is_steady()

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

inlineoverridevirtualinherited

This is not a steady-state solver.

Implements libMesh::TimeSolver.

Definition at line 153 of file unsteady_solver.h.

{ return false; }

linear_solver()

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

inlinevirtualinherited

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

Reimplemented in libMesh::AdaptiveTimeSolver.

Definition at line 186 of file time_solver.h.

{ return _linear_solver; }

References libMesh::TimeSolver::_linear_solver.

Referenced by libMesh::TimeSolver::init(), libMesh::TimeSolver::init_data(), and libMesh::TimeSolver::reinit().

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.

  { return _n_objects; }

References libMesh::ReferenceCounter::_n_objects.

nonlocal_residual()

virtual bool libMesh::TimeSolver::nonlocal_residual ( bool  request_jacobian, DiffContext &    )

pure virtualinherited

This method uses the DifferentiablePhysics nonlocal_time_derivative(), nonlocal_constraint(), and nonlocal_mass_residual() to build a full residual of non-local terms.

What combination it uses will depend on the type of solver. See the subclasses for more details.

Implemented in libMesh::NewmarkSolver, libMesh::SteadySolver, libMesh::Euler2Solver, libMesh::EulerSolver, libMesh::EigenTimeSolver, and libMesh::AdaptiveTimeSolver.

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

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.

{
  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);
}

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(), libMesh::NewmarkSolver::_general_residual(), and libMesh::FEMPhysics::eulerian_residual().

prepare_accel()

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

protected

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.

{
  context.get_elem_solution_accel() = context.get_elem_solution_rate();
 
  context.elem_solution_accel_derivative = context.get_elem_solution_rate_derivative();
}

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().

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.

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

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

reinit()

void libMesh::UnsteadySolver::reinit ( )

overridevirtualinherited

The reinitialization function.

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

Reimplemented from libMesh::TimeSolver.

Reimplemented in libMesh::SecondOrderUnsteadySolver, and libMesh::AdaptiveTimeSolver.

Definition at line 70 of file unsteady_solver.C.

{
  TimeSolver::reinit();
 
#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
 
  // localize the old solution
  NumericVector<Number> & old_nonlinear_soln =
    _system.get_vector("_old_nonlinear_solution");
 
  old_nonlinear_soln.localize
    (*old_local_nonlinear_solution,
     _system.get_dof_map().get_send_list());
}

References libMesh::TimeSolver::_system, libMesh::System::get_dof_map(), libMesh::DofMap::get_send_list(), libMesh::System::get_vector(), libMesh::GHOSTED, libMesh::NumericVector< T >::localize(), libMesh::System::n_dofs(), libMesh::System::n_local_dofs(), libMesh::UnsteadySolver::old_local_nonlinear_solution, libMesh::TimeSolver::reinit(), and libMesh::SERIAL.

Referenced by libMesh::SecondOrderUnsteadySolver::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.

{
  // 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());
}

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.

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 239 of file time_solver.h.

  { _is_adjoint = _is_adjoint_value; }

References libMesh::TimeSolver::_is_adjoint.

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

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 96 of file time_solver.C.

{
  solution_history = _solution_history.clone();
}

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

side_residual()

virtual bool libMesh::TimeSolver::side_residual ( bool  request_jacobian, DiffContext &    )

pure virtualinherited

This method uses the DifferentiablePhysics side_time_derivative(), side_constraint(), and side_mass_residual() to build a full residual on an element's side.

What combination it uses will depend on the type of solver. See the subclasses for more details.

Implemented in libMesh::NewmarkSolver, libMesh::SteadySolver, libMesh::Euler2Solver, libMesh::EulerSolver, libMesh::EigenTimeSolver, and libMesh::AdaptiveTimeSolver.

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

solve()

void libMesh::UnsteadySolver::solve ( )

overridevirtualinherited

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.

Reimplemented from libMesh::TimeSolver.

Reimplemented in libMesh::AdaptiveTimeSolver, libMesh::NewmarkSolver, and libMesh::TwostepTimeSolver.

Definition at line 93 of file unsteady_solver.C.

{
  if (first_solve)
    {
      advance_timestep();
      first_solve = false;
    }
 
  unsigned int solve_result = _diff_solver->solve();
 
  // If we requested the UnsteadySolver to attempt reducing dt after a
  // failed DiffSolver solve, check the results of the solve now.
  if (reduce_deltat_on_diffsolver_failure)
    {
      bool backtracking_failed =
        solve_result & DiffSolver::DIVERGED_BACKTRACKING_FAILURE;
 
      bool max_iterations =
        solve_result & DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS;
 
      if (backtracking_failed || max_iterations)
        {
          // Cut timestep in half
          for (unsigned int nr=0; nr<reduce_deltat_on_diffsolver_failure; ++nr)
            {
              _system.deltat *= 0.5;
              libMesh::out << "Newton backtracking failed.  Trying with smaller timestep, dt="
                           << _system.deltat << std::endl;
 
              solve_result = _diff_solver->solve();
 
              // Check solve results with reduced timestep
              bool backtracking_still_failed =
                solve_result & DiffSolver::DIVERGED_BACKTRACKING_FAILURE;
 
              bool backtracking_max_iterations =
                solve_result & DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS;
 
              if (!backtracking_still_failed && !backtracking_max_iterations)
                {
                  if (!quiet)
                    libMesh::out << "Reduced dt solve succeeded." << std::endl;
                  return;
                }
            }
 
          // If we made it here, we still couldn't converge the solve after
          // reducing deltat
          libMesh::out << "DiffSolver::solve() did not succeed after "
                       << reduce_deltat_on_diffsolver_failure
                       << " attempts." << std::endl;
          libmesh_convergence_failure();
 
        } // end if (backtracking_failed || max_iterations)
    } // end if (reduce_deltat_on_diffsolver_failure)
}

References libMesh::TimeSolver::_diff_solver, libMesh::TimeSolver::_system, libMesh::UnsteadySolver::advance_timestep(), libMesh::DifferentiableSystem::deltat, libMesh::DiffSolver::DIVERGED_BACKTRACKING_FAILURE, libMesh::DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS, libMesh::UnsteadySolver::first_solve, libMesh::out, libMesh::TimeSolver::quiet, and libMesh::TimeSolver::reduce_deltat_on_diffsolver_failure.

Referenced by libMesh::NewmarkSolver::solve().

system() [1/2]

sys_type& libMesh::TimeSolver::system ( )

inlineinherited

Returns

A writable reference to the system we are solving.

Definition at line 176 of file time_solver.h.

{ return _system; }

References libMesh::TimeSolver::_system.

system() [2/2]

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

inlineinherited

Returns

A constant reference to the system we are solving.

Definition at line 171 of file time_solver.h.

{ return _system; }

References libMesh::TimeSolver::_system.

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

time_order()

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

inlineoverridevirtual

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 247 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().

_is_adjoint

bool libMesh::TimeSolver::_is_adjoint

privateinherited

This boolean tells the TimeSolver whether we are solving a primal or adjoint problem.

Definition at line 280 of file time_solver.h.

Referenced by libMesh::TimeSolver::is_adjoint(), and libMesh::TimeSolver::set_is_adjoint().

_linear_solver

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

protectedinherited

An implicit linear solver to use for adjoint problems.

Definition at line 252 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 257 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(), 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(), libMesh::TwostepTimeSolver::solve(), libMesh::UnsteadySolver::solve(), libMesh::EigenTimeSolver::solve(), and libMesh::TimeSolver::system().

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 167 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 161 of file unsteady_solver.h.

Referenced by libMesh::NewmarkSolver::advance_timestep(), libMesh::AdaptiveTimeSolver::advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), libMesh::TwostepTimeSolver::solve(), and libMesh::UnsteadySolver::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 137 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 191 of file time_solver.h.

Referenced by libMesh::TwostepTimeSolver::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 220 of file time_solver.h.

Referenced by libMesh::TwostepTimeSolver::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 264 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().

---

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

• include/solvers/first_order_unsteady_solver.h
• src/solvers/first_order_unsteady_solver.C