libMesh::Euler2Solver Class Reference

This class defines a theta-method (defaulting to Backward Euler with theta = 1.0) solver to handle time integration of DifferentiableSystems. More...

#include <euler2_solver.h>

Inheritance diagram for libMesh::Euler2Solver:

Public Types
typedef FirstOrderUnsteadySolver	Parent
	The parent class.
typedef DifferentiableSystem	sys_type
	The type of system.

Public Member Functions
	Euler2Solver (sys_type &s)
	Constructor.
virtual	~Euler2Solver ()
	Destructor.
virtual Real	error_order () const override
	Error convergence order: 2 for Crank-Nicolson, 1 otherwise.
virtual void	integrate_qoi_timestep () override
	A method to integrate the system::QoI functionals.
virtual void	integrate_adjoint_refinement_error_estimate (AdjointRefinementEstimator &adjoint_refinement_error_estimator, ErrorVector &QoI_elementwise_error) override
	A method to compute the adjoint refinement error estimate at the current timestep.
virtual bool	element_residual (bool request_jacobian, DiffContext &) override
	This method uses the DifferentiablePhysics' element_time_derivative() and element_constraint() to build a full residual on an element.
virtual bool	side_residual (bool request_jacobian, DiffContext &) override
	This method uses the DifferentiablePhysics' side_time_derivative() and side_constraint() to build a full residual on an element's side.
virtual bool	nonlocal_residual (bool request_jacobian, DiffContext &) override
	This method uses the DifferentiablePhysics' nonlocal_time_derivative() and nonlocal_constraint() to build a full residual for non-local terms.
virtual unsigned int	time_order () const override
virtual void	init () override
	The initialization function.
virtual void	init_adjoints () override
	Add adjoint vectors and old_adjoint_vectors as per the indices of QoISet.
virtual void	init_data () override
	The data initialization function.
virtual void	reinit () override
	The reinitialization function.
virtual void	solve () override
	This method solves for the solution at the next timestep.
virtual void	advance_timestep () override
	This method advances the solution to the next timestep, after a solve() has been performed.
void	update ()
virtual std::pair< unsigned int, Real >	adjoint_solve (const QoISet &qoi_indices) override
	This method solves for the adjoint solution at the next adjoint timestep (or a steady state adjoint solve)
virtual void	adjoint_advance_timestep () override
	This method advances the adjoint solution to the previous timestep, after an adjoint_solve() has been performed.
virtual void	retrieve_timestep () override
	This method retrieves all the stored solutions at the current system.time.
virtual void	integrate_adjoint_sensitivity (const QoISet &qois, const ParameterVector &parameter_vector, SensitivityData &sensitivities) override
	A method to integrate the adjoint sensitivity w.r.t a given parameter vector.
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.
virtual bool	is_steady () const override
	This is not a steady-state solver.
void	set_first_adjoint_step (bool first_adjoint_step_setting)
	A setter for the first_adjoint_step boolean.
void	set_first_solve (bool first_solve_setting)
virtual void	before_timestep ()
	This method is for subclasses or users to override to do arbitrary processing between timesteps.
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.
virtual std::unique_ptr< LinearSolver< Number > > &	linear_solver ()
	An implicit linear solver to use for adjoint and sensitivity problems.
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.
SolutionHistory &	get_solution_history ()
	A getter function that returns a reference to the solution history object owned by TimeSolver.
bool	is_adjoint () const
	Accessor for querying whether we need to do a primal or adjoint solve.
void	set_is_adjoint (bool _is_adjoint_value)
	Accessor for setting whether we need to do a primal or adjoint solve.
virtual Real	last_completed_timestep_size ()
	Returns system.deltat if fixed timestep solver is used, the complete timestep size (sum of all substeps) if the adaptive time solver is used.

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

Public Attributes
Real	theta
	The value for the theta method to employ: 1.0 corresponds to backwards Euler, 0.0 corresponds to forwards Euler, 0.5 corresponds to a Crank-Nicolson-like scheme.
std::shared_ptr< NumericVector< Number > >	old_local_nonlinear_solution
	Serial vector of _system.get_vector("_old_nonlinear_solution") This is a shared_ptr so that it can be shared between different derived class instances, as in e.g.
bool	quiet
	Print extra debugging information if quiet == false.
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.

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

Protected Member Functions
virtual bool	_general_residual (bool request_jacobian, DiffContext &, ResFuncType mass, ResFuncType damping, ResFuncType time_deriv, ResFuncType constraint, ReinitFuncType reinit, bool compute_second_order_eqns)
	This method is the underlying implementation of the public residual methods.
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.
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.
void	increment_constructor_count (const std::string &name) noexcept
	Increments the construction counter.
void	increment_destructor_count (const std::string &name) noexcept
	Increments the destruction counter.

Protected Attributes
bool	first_solve
	A bool that will be true the first time solve() is called, and false thereafter.
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.
std::vector< std::unique_ptr< NumericVector< Number > > >	old_adjoints
	A vector of pointers to vectors holding the adjoint solution at the last time step.
Real	last_step_deltat
	We will need to move the system.time around to ensure that residuals are built with the right deltat and the right time.
Real	next_step_deltat
std::unique_ptr< DiffSolver >	_diff_solver
	An implicit linear or nonlinear solver to use at each timestep.
std::unique_ptr< LinearSolver< Number > >	_linear_solver
	An implicit linear solver to use for adjoint problems.
sys_type &	_system
	A reference to the system we are solving.
std::unique_ptr< SolutionHistory >	solution_history
	A std::unique_ptr to a SolutionHistory object.
Real	last_deltat
	The deltat for the last completed timestep before the current one.

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

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

Detailed Description

This class defines a theta-method (defaulting to Backward Euler with theta = 1.0) solver to handle time integration of DifferentiableSystems.

The "Euler2" solver differs from Euler in how it evaluates residuals at intermediate theta values: Euler solves m(u,u') = f(theta*u_new + (1-theta)*u_old), Euler2 solves m(u') = theta*f(u_new) + (1-theta)*f(u_old) i.e. the trapezoidal rule for theta = 0.5

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

2006

Definition at line 48 of file euler2_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 119 of file reference_counter.h.

Parent

typedef FirstOrderUnsteadySolver libMesh::Euler2Solver::Parent

The parent class.

Definition at line 54 of file euler2_solver.h.

ReinitFuncType

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

protectedinherited

Definition at line 327 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 325 of file time_solver.h.

sys_type

typedef DifferentiableSystem libMesh::TimeSolver::sys_type

inherited

The type of system.

Definition at line 69 of file time_solver.h.

Constructor & Destructor Documentation

Euler2Solver()

libMesh::Euler2Solver::Euler2Solver ( sys_type &  s )

explicit

Constructor.

Requires a reference to the system to be solved.

Definition at line 33 of file euler2_solver.C.

  : FirstOrderUnsteadySolver(s), theta(1.)
{
}

~Euler2Solver()

libMesh::Euler2Solver::~Euler2Solver ( )

virtualdefault

Destructor.

Member Function Documentation

_general_residual()

bool libMesh::Euler2Solver::_general_residual ( bool  request_jacobian, DiffContext &  context, ResFuncType  mass, ResFuncType  damping, ResFuncType  time_deriv, ResFuncType  constraint, ReinitFuncType  reinit, bool  compute_second_order_eqns  )

protectedvirtual

This method is the underlying implementation of the public residual methods.

Definition at line 103 of file euler2_solver.C.

{
  unsigned int n_dofs = context.get_elem_solution().size();
 
  // Local nonlinear solution at old timestep
  DenseVector<Number> old_elem_solution(n_dofs);
  for (unsigned int i=0; i != n_dofs; ++i)
    old_elem_solution(i) =
      old_nonlinear_solution(context.get_dof_indices()[i]);
 
  // Local time derivative of solution
  context.get_elem_solution_rate() = context.get_elem_solution();
  context.get_elem_solution_rate() -= old_elem_solution;
  context.elem_solution_rate_derivative = 1 / _system.deltat;
  context.get_elem_solution_rate() *=
    context.elem_solution_rate_derivative;
 
  // Our first evaluations are at the final elem_solution
  context.elem_solution_derivative = 1.0;
 
  // If a fixed solution is requested, we'll use the elem_solution
  // at the new timestep
  // FIXME - should this be the theta solution instead?
  if (_system.use_fixed_solution)
    context.get_elem_fixed_solution() = context.get_elem_solution();
 
  context.fixed_solution_derivative = 1.0;
 
  // We need to save the old jacobian and old residual since we'll be
  // multiplying some of the new contributions by theta or 1-theta
  DenseMatrix<Number> old_elem_jacobian(n_dofs, n_dofs);
  DenseVector<Number> old_elem_residual(n_dofs);
  old_elem_residual.swap(context.get_elem_residual());
  if (request_jacobian)
    old_elem_jacobian.swap(context.get_elem_jacobian());
 
  // Local time derivative of solution
  context.get_elem_solution_rate() = context.get_elem_solution();
  context.get_elem_solution_rate() -= old_elem_solution;
  context.elem_solution_rate_derivative = 1 / _system.deltat;
  context.get_elem_solution_rate() *=
    context.elem_solution_rate_derivative;
 
  // If we are asked to compute residuals for second order variables,
  // we also populate the acceleration part so the user can use that.
  if (compute_second_order_eqns)
    this->prepare_accel(context);
 
  // Move the mesh into place first if necessary, set t = t_{n+1}
  (context.*reinit_func)(1.);
 
  // First, evaluate time derivative at the new timestep.
  // The element should already be in the proper place
  // even for a moving mesh problem.
  bool jacobian_computed =
    (_system.get_physics()->*time_deriv)(request_jacobian, context);
 
  // Next, evaluate the mass residual at the new timestep
 
  jacobian_computed = (_system.get_physics()->*mass)(jacobian_computed, context) &&
    jacobian_computed;
 
  // If we have second-order variables, we need to get damping terms
  // and the velocity equations
  if (compute_second_order_eqns)
    {
      jacobian_computed = (_system.get_physics()->*damping)(jacobian_computed, context) &&
        jacobian_computed;
 
      jacobian_computed = this->compute_second_order_eqns(jacobian_computed, context) &&
        jacobian_computed;
    }
 
  // Add the constraint term
  jacobian_computed = (_system.get_physics()->*constraint)(jacobian_computed, context) &&
    jacobian_computed;
 
  // The new solution's contribution is scaled by theta
  context.get_elem_residual() *= theta;
  context.get_elem_jacobian() *= theta;
 
  // Save the new solution's term
  DenseMatrix<Number> elem_jacobian_newterm(n_dofs, n_dofs);
  DenseVector<Number> elem_residual_newterm(n_dofs);
  elem_residual_newterm.swap(context.get_elem_residual());
  if (request_jacobian)
    elem_jacobian_newterm.swap(context.get_elem_jacobian());
 
  // Add the time-dependent term for the old solution
 
  // Make sure elem_solution is set up for elem_reinit to use
  // Move elem_->old_, old_->elem_
  context.get_elem_solution().swap(old_elem_solution);
  context.elem_solution_derivative = 0.0;
 
  // Move the mesh into place if necessary, set t = t_{n}
  (context.*reinit_func)(0.);
 
  jacobian_computed =
    (_system.get_physics()->*time_deriv)(jacobian_computed, context) &&
    jacobian_computed;
 
  // Add the mass residual term for the old solution
 
  // Evaluating the mass residual at both old and new timesteps will be
  // redundant in most problems but may be necessary for time accuracy
  // or stability in moving mesh problems or problems with user-overridden
  // mass_residual functions
 
  jacobian_computed =
    (_system.get_physics()->*mass)(jacobian_computed, context) &&
    jacobian_computed;
 
  // If we have second-order variables, we need to get damping terms
  // and the velocity equations
  if (compute_second_order_eqns)
    {
      jacobian_computed = (_system.get_physics()->*damping)(jacobian_computed, context) &&
        jacobian_computed;
 
      jacobian_computed = this->compute_second_order_eqns(jacobian_computed, context) &&
        jacobian_computed;
    }
 
  // The old solution's contribution is scaled by (1-theta)
  context.get_elem_residual() *= (1-theta);
  context.get_elem_jacobian() *= (1-theta);
 
  // Restore the elem_solution
  // Move elem_->elem_, old_->old_
  context.get_elem_solution().swap(old_elem_solution);
  context.elem_solution_derivative = 1;
 
  // Restore the elem position if necessary, set t = t_{n+1}
  (context.*reinit_func)(1.);
 
  // Add back (or restore) the old residual/jacobian
  context.get_elem_residual() += old_elem_residual;
  if (request_jacobian)
    {
      if (jacobian_computed)
        context.get_elem_jacobian() += old_elem_jacobian;
      else
        context.get_elem_jacobian().swap(old_elem_jacobian);
    }
 
  // Add the saved new-solution terms
  context.get_elem_residual() += elem_residual_newterm;
  if (jacobian_computed)
    context.get_elem_jacobian() += elem_jacobian_newterm;
 
  return jacobian_computed;
}

References libMesh::TimeSolver::_system, libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns(), libMesh::DifferentiableSystem::deltat, libMesh::DiffContext::elem_solution_derivative, libMesh::DiffContext::elem_solution_rate_derivative, libMesh::DiffContext::fixed_solution_derivative, libMesh::DiffContext::get_dof_indices(), libMesh::DiffContext::get_elem_fixed_solution(), libMesh::DiffContext::get_elem_jacobian(), libMesh::DiffContext::get_elem_residual(), libMesh::DiffContext::get_elem_solution(), libMesh::DiffContext::get_elem_solution_rate(), libMesh::DifferentiableSystem::get_physics(), libMesh::UnsteadySolver::old_nonlinear_solution(), libMesh::FirstOrderUnsteadySolver::prepare_accel(), libMesh::DenseVector< T >::size(), libMesh::DenseMatrix< T >::swap(), libMesh::DenseVector< T >::swap(), theta, and libMesh::System::use_fixed_solution.

Referenced by element_residual(), nonlocal_residual(), and side_residual().

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::AdaptiveTimeSolver, and libMesh::NewmarkSolver.

Definition at line 239 of file unsteady_solver.C.

{
  // Call the store function to store the adjoint we have computed (or
  // for first_adjoint_step, the adjoint initial condition) in this
  // time step for the time instance.
  solution_history->store(true, _system.time);
 
  // Before moving to the next time instant, copy over the current adjoint solutions into _old_adjoint_solutions
  for(auto i : make_range(_system.n_qois()))
  {
   std::string old_adjoint_solution_name = "_old_adjoint_solution";
   old_adjoint_solution_name+= std::to_string(i);
   NumericVector<Number> & old_adjoint_solution_i = _system.get_vector(old_adjoint_solution_name);
   NumericVector<Number> & adjoint_solution_i = _system.get_adjoint_solution(i);
   old_adjoint_solution_i = adjoint_solution_i;
  }
 
  _system.time -= _system.deltat;
 
  // Retrieve the primal solution vectors at this new (or for
  // first_adjoint_step, initial) time instance. These provide the
  // data to solve the adjoint problem for the next time instance.
  solution_history->retrieve(true, _system.time);
 
  // 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::System::get_adjoint_solution(), libMesh::System::get_dof_map(), libMesh::DofMap::get_send_list(), libMesh::System::get_vector(), libMesh::NumericVector< T >::localize(), libMesh::make_range(), libMesh::System::n_qois(), libMesh::UnsteadySolver::old_local_nonlinear_solution, libMesh::TimeSolver::solution_history, and libMesh::System::time.

adjoint_solve()

std::pair< unsigned int, Real > libMesh::UnsteadySolver::adjoint_solve ( const QoISet &  qoi_indices )

overridevirtualinherited

This method solves for the adjoint solution at the next adjoint timestep (or a steady state adjoint solve)

Reimplemented from libMesh::TimeSolver.

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

Definition at line 228 of file unsteady_solver.C.

{
  std::pair<unsigned int, Real> adjoint_output = _system.ImplicitSystem::adjoint_solve(qoi_indices);
 
  // Record the deltat we used for this adjoint timestep. This was determined completely
  // by SolutionHistory::retrieve methods. The adjoint_solve methods should never change deltat.
  last_deltat = _system.deltat;
 
  return adjoint_output;
}

References libMesh::TimeSolver::_system, libMesh::DifferentiableSystem::deltat, and libMesh::TimeSolver::last_deltat.

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 192 of file unsteady_solver.C.

{
  // The first access of advance_timestep happens via solve, not user code
  // It is used here to store any initial conditions data
  if (!first_solve)
    {
      // We call advance_timestep in user code after solve, so any solutions
      // we will be storing will be for the next time instance
      _system.time += _system.deltat;
    }
    else
    {
      // We are here because of a call to advance_timestep that happens
      // via solve, the very first solve. All we are doing here is storing
      // the initial condition. The actual solution computed via this solve
      // will be stored when we call advance_timestep in the user's timestep loop
      first_solve = false;
    }
 
  // If the user has attached a memory or file solution history object
  // to the solver, this will store the current solution indexed with
  // the current time
  solution_history->store(false, _system.time);
 
  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 205 of file time_solver.h.

{}

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 \( \dot{u} - v = 0 \), 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 33 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 : make_range(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::FEAbstract::get_JxW(), libMesh::FEGenericBase< OutputType >::get_phi(), 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::make_range(), libMesh::QBase::n_points(), libMesh::DiffContext::n_vars(), libMesh::Variable::type(), and libMesh::System::variable().

Referenced by _general_residual(), libMesh::EulerSolver::_general_residual(), element_residual(), libMesh::EulerSolver::element_residual(), nonlocal_residual(), and libMesh::EulerSolver::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 220 of file time_solver.h.

{ return _diff_solver; }

References libMesh::TimeSolver::_diff_solver.

Referenced by libMesh::TimeSolver::adjoint_solve(), adjust_linear_solvers(), 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 100 of file reference_counter.C.

{
  _enable_print_counter = false;
  return;
}

References libMesh::ReferenceCounter::_enable_print_counter.

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 348 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(), and libMesh::System::solution.

element_residual()

bool libMesh::Euler2Solver::element_residual ( bool  request_jacobian, DiffContext &  context  )

overridevirtual

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

What combination it uses will depend on theta.

Implements libMesh::TimeSolver.

Definition at line 54 of file euler2_solver.C.

{
  bool compute_second_order_eqns = !this->_system.get_physics()->get_second_order_vars().empty();
 
  return this->_general_residual(request_jacobian,
                                 context,
                                 &DifferentiablePhysics::mass_residual,
                                 &DifferentiablePhysics::damping_residual,
                                 &DifferentiablePhysics::_eulerian_time_deriv,
                                 &DifferentiablePhysics::element_constraint,
                                 &DiffContext::elem_reinit,
                                 compute_second_order_eqns);
}

References libMesh::DifferentiablePhysics::_eulerian_time_deriv(), _general_residual(), libMesh::TimeSolver::_system, libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns(), libMesh::DifferentiablePhysics::damping_residual(), libMesh::DiffContext::elem_reinit(), libMesh::DifferentiablePhysics::element_constraint(), libMesh::DifferentiableSystem::get_physics(), libMesh::DifferentiablePhysics::get_second_order_vars(), and libMesh::DifferentiablePhysics::mass_residual().

enable_print_counter_info()

void libMesh::ReferenceCounter::enable_print_counter_info ( )

staticinherited

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

Enabled by default.

Definition at line 94 of file reference_counter.C.

{
  _enable_print_counter = true;
  return;
}

References libMesh::ReferenceCounter::_enable_print_counter.

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

error_order()

Real libMesh::Euler2Solver::error_order ( ) const

overridevirtual

Error convergence order: 2 for Crank-Nicolson, 1 otherwise.

Implements libMesh::UnsteadySolver.

Definition at line 44 of file euler2_solver.C.

{
  if (theta == 0.5)
    return 2.;
  return 1.;
}

References theta.

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 & [name, cd] : _counts)
    oss << "| " << name << " reference count information:\n"
        << "|  Creations:    " << cd.first    << '\n'
        << "|  Destructions: " << cd.second << '\n';
 
  oss << " ---------------------------------------------------------------------------- \n";
 
  return oss.str();
 
#else
 
  return "";
 
#endif
}

References libMesh::ReferenceCounter::_counts.

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

get_solution_history()

SolutionHistory & libMesh::TimeSolver::get_solution_history ( )

inherited

A getter function that returns a reference to the solution history object owned by TimeSolver.

Definition at line 124 of file time_solver.C.

{
  return *solution_history;
}

References libMesh::TimeSolver::solution_history.

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

increment_constructor_count()

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

inlineprotectednoexceptinherited

Increments the construction counter.

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

Definition at line 183 of file reference_counter.h.

{
  libmesh_try
  {
    Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
    std::pair<unsigned int, unsigned int> & p = _counts[name];
    p.first++;
  }
  libmesh_catch (...)
  {
    auto stream = libMesh::err.get();
    stream->exceptions(stream->goodbit); // stream must not throw
    libMesh::err << "Encountered unrecoverable error while calling "
                 << "ReferenceCounter::increment_constructor_count() "
                 << "for a(n) " << name << " object." << std::endl;
    std::terminate();
  }
}

References libMesh::err, libMesh::BasicOStreamProxy< charT, traits >::get(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< T >::ReferenceCountedObject(), libMesh::ReferenceCountedObject< T >::ReferenceCountedObject(), and libMesh::ReferenceCountedObject< T >::ReferenceCountedObject().

increment_destructor_count()

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

inlineprotectednoexceptinherited

Increments the destruction counter.

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

Definition at line 207 of file reference_counter.h.

{
  libmesh_try
  {
    Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
    std::pair<unsigned int, unsigned int> & p = _counts[name];
    p.second++;
  }
  libmesh_catch (...)
  {
    auto stream = libMesh::err.get();
    stream->exceptions(stream->goodbit); // stream must not throw
    libMesh::err << "Encountered unrecoverable error while calling "
                 << "ReferenceCounter::increment_destructor_count() "
                 << "for a(n) " << name << " object." << std::endl;
    std::terminate();
  }
}

References libMesh::err, libMesh::BasicOStreamProxy< charT, traits >::get(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< T >::~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 60 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_adjoints()

void libMesh::UnsteadySolver::init_adjoints ( )

overridevirtualinherited

Add adjoint vectors and old_adjoint_vectors as per the indices of QoISet.

Reimplemented from libMesh::TimeSolver.

Definition at line 68 of file unsteady_solver.C.

{
  TimeSolver::init_adjoints();
 
  // Add old adjoint solutions
  // To keep the number of vectors consistent between the primal and adjoint
  // time loops, we will also add the adjoint rhs vector during initialization
  for(auto i : make_range(_system.n_qois()))
  {
    std::string old_adjoint_solution_name = "_old_adjoint_solution";
    old_adjoint_solution_name+= std::to_string(i);
    _system.add_vector(old_adjoint_solution_name, false, GHOSTED);
 
    std::string adjoint_rhs_name = "adjoint_rhs";
    adjoint_rhs_name+= std::to_string(i);
    _system.add_vector(adjoint_rhs_name, false, GHOSTED);
  }
 
}

References libMesh::TimeSolver::_system, libMesh::System::add_vector(), libMesh::GHOSTED, libMesh::TimeSolver::init_adjoints(), libMesh::make_range(), and libMesh::System::n_qois().

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 89 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().

integrate_adjoint_refinement_error_estimate()

void libMesh::Euler2Solver::integrate_adjoint_refinement_error_estimate ( AdjointRefinementEstimator &  adjoint_refinement_error_estimator, ErrorVector &  QoI_elementwise_error  )

overridevirtual

A method to compute the adjoint refinement error estimate at the current timestep.

int_{tstep_start}^{tstep_end} R(u^h,z) dt. The user provides an initialized ARefEE object. Fills in an ErrorVector that contains the weighted sum of errors from all the QoIs and can be used to guide AMR. The integration scheme used is consistent with the theta used for the unsteady solution. CURRENTLY ONLY SUPPORTED for Backward Euler.

Implements libMesh::FirstOrderUnsteadySolver.

Definition at line 322 of file euler2_solver.C.

{
  // Currently, we only support this functionality when Backward-Euler time integration is used.
  if (theta != 1.0)
  libmesh_not_implemented();
 
  // There are two possibilities regarding the integration rule we need to use for time integration.
  // If we have a instantaneous QoI, then we need to use a left sided Riemann sum, otherwise the trapezoidal rule for temporally smooth QoIs.
 
  // Create left and right error estimate vectors of the right size
  std::vector<Number> qoi_error_estimates_left(_system.n_qois());
  std::vector<Number> qoi_error_estimates_right(_system.n_qois());
 
  // Get t_j
  Real time_left = _system.time;
 
  // Get f(t_j)
  ErrorVector QoI_elementwise_error_left;
 
  // If we are at the very initial step, the error contribution is zero,
  // otherwise the old ajoint vector has been filled and we are the left end
  // of a subsequent timestep or sub-timestep
  if(old_adjoints[0] != nullptr)
  {
    // For evaluating the residual, we need to use the deltat that was used
    // to get us to this solution, so we save the current deltat as next_step_deltat
    // and set _system.deltat to the last completed deltat.
    next_step_deltat = _system.deltat;
    _system.deltat = last_step_deltat;
 
    // The adjoint error estimate expression for a backwards facing step
    // scheme needs the adjoint for the last time instant, so save the current adjoint for future use
    for (auto j : make_range(_system.n_qois()))
    {
      // Swap for residual weighting
      _system.get_adjoint_solution(j).swap(*old_adjoints[j]);
    }
 
    _system.update();
 
    // The residual has to be evaluated at the last time
    _system.time = _system.time - last_step_deltat;
 
    adjoint_refinement_error_estimator.estimate_error(_system, QoI_elementwise_error_left);
 
    // Shift the time back
    _system.time = _system.time + last_step_deltat;
 
    // Swap back the current and old adjoints
    for (auto j : make_range(_system.n_qois()))
    {
      _system.get_adjoint_solution(j).swap(*old_adjoints[j]);
    }
 
    // Set the system deltat back to what it should be to march to the next time
    _system.deltat = next_step_deltat;
 
  }
  else
  {
    for(auto i : index_range(QoI_elementwise_error))
      QoI_elementwise_error_left[i] = 0.0;
  }
 
  // Also get the left side contributions for the spatially integrated errors for all the QoIs in the QoI set
  for (auto j : make_range(_system.n_qois()))
  {
    // Skip this QoI if not in the QoI Set
    if (adjoint_refinement_error_estimator.qoi_set().has_index(j))
    {
      // If we are at the initial time, the error contribution is zero
      if(std::abs(_system.time) > TOLERANCE*sqrt(TOLERANCE))
      {
        qoi_error_estimates_left[j] = adjoint_refinement_error_estimator.get_global_QoI_error_estimate(j);
      }
      else
      {
        qoi_error_estimates_left[j] = 0.0;
      }
    }
  }
 
  // Advance to t_j+1
  _system.time = _system.time + _system.deltat;
 
  // Get t_j+1
  Real time_right = _system.time;
 
  // We will need to use the last step deltat for the weighted residual evaluation
  last_step_deltat = _system.deltat;
 
  // The adjoint error estimate expression for a backwards facing step
  // scheme needs the adjoint for the last time instant, so save the current adjoint for future use
  for (auto j : make_range(_system.n_qois()))
  {
    old_adjoints[j] = _system.get_adjoint_solution(j).clone();
  }
 
  // Retrieve the state and adjoint vectors for the next time instant
  retrieve_timestep();
 
  // Swap for residual weighting
  for (auto j : make_range(_system.n_qois()))
  {
   _system.get_adjoint_solution(j).swap(*old_adjoints[j]);
  }
 
  // Swap out the deltats as we did for the left side
  next_step_deltat = _system.deltat;
  _system.deltat = last_step_deltat;
 
  // Get f(t_j+1)
  ErrorVector QoI_elementwise_error_right;
 
  _system.update();
 
  // The residual has to be evaluated at the last time
  _system.time = _system.time - last_step_deltat;
 
  adjoint_refinement_error_estimator.estimate_error(_system, QoI_elementwise_error_right);
 
  // Shift the time back
  _system.time = _system.time + last_step_deltat;
 
  // Set the system deltat back to what it needs to be able to march to the next time
  _system.deltat = next_step_deltat;
 
  // Swap back now that the residual weighting is done
  for (auto j : make_range(_system.n_qois()))
  {
   _system.get_adjoint_solution(j).swap(*old_adjoints[j]);
  }
 
  // Also get the right side contributions for the spatially integrated errors for all the QoIs in the QoI set
  for (auto j : make_range(_system.n_qois()))
  {
    // Skip this QoI if not in the QoI Set
    if (adjoint_refinement_error_estimator.qoi_set().has_index(j))
    {
      qoi_error_estimates_right[j] = adjoint_refinement_error_estimator.get_global_QoI_error_estimate(j);
    }
  }
 
  // Error contribution from this timestep
  for (auto i : index_range(QoI_elementwise_error))
    QoI_elementwise_error[i] = float(((QoI_elementwise_error_right[i] + QoI_elementwise_error_left[i])/2)
                                     * (time_right - time_left));
 
  // QoI set spatially integrated errors contribution from this timestep
  for (auto j : make_range(_system.n_qois()))
  {
    // Skip this QoI if not in the QoI Set
    if (adjoint_refinement_error_estimator.qoi_set().has_index(j))
    {
      _system.set_qoi_error_estimate(j, ( (1.0 - theta)*qoi_error_estimates_left[j] + theta*qoi_error_estimates_right[j] )*last_step_deltat);
    }
  }
 
}

References libMesh::TimeSolver::_system, libMesh::NumericVector< T >::clone(), libMesh::DifferentiableSystem::deltat, libMesh::AdjointRefinementEstimator::estimate_error(), libMesh::System::get_adjoint_solution(), libMesh::AdjointRefinementEstimator::get_global_QoI_error_estimate(), libMesh::QoISet::has_index(), libMesh::index_range(), libMesh::UnsteadySolver::last_step_deltat, libMesh::make_range(), libMesh::System::n_qois(), libMesh::UnsteadySolver::next_step_deltat, libMesh::UnsteadySolver::old_adjoints, libMesh::AdjointRefinementEstimator::qoi_set(), libMesh::Real, libMesh::UnsteadySolver::retrieve_timestep(), libMesh::System::set_qoi_error_estimate(), libMesh::NumericVector< T >::swap(), theta, libMesh::System::time, libMesh::TOLERANCE, and libMesh::System::update().

integrate_adjoint_sensitivity()

void libMesh::UnsteadySolver::integrate_adjoint_sensitivity ( const QoISet &  qois, const ParameterVector &  parameter_vector, SensitivityData &  sensitivities  )

overridevirtualinherited

A method to integrate the adjoint sensitivity w.r.t a given parameter vector.

int_{tstep_start}^{tstep_end} dQ/dp dt = int_{tstep_start}^{tstep_end} (\partialQ / \partial p) - ( \partial R (u,z) / \partial p ) dt The trapezoidal rule is used to numerically integrate the timestep.

Reimplemented from libMesh::TimeSolver.

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

Definition at line 280 of file unsteady_solver.C.

{
  // CURRENTLY using the trapezoidal rule to integrate each timestep
  // (f(t_j) + f(t_j+1))/2 (t_j+1 - t_j)
  // Fix me: This function needs to be moved to the EulerSolver classes like the
  // other integrate_timestep functions, and use an integration rule consistent with
  // the theta method used for the time integration.
 
  // Get t_j
  Real time_left = _system.time;
 
  // Left side sensitivities to hold f(t_j)
  SensitivityData sensitivities_left(qois, _system, parameter_vector);
 
  // Get f(t_j)
  _system.adjoint_qoi_parameter_sensitivity(qois, parameter_vector, sensitivities_left);
 
  // Advance to t_j+1
  _system.time = _system.time + _system.deltat;
 
  // Get t_j+1
  Real time_right = _system.time;
 
  // Right side sensitivities f(t_j+1)
  SensitivityData sensitivities_right(qois, _system, parameter_vector);
 
  // Remove the sensitivity rhs vector from system since we did not write it to file and it cannot be retrieved
  _system.remove_vector("sensitivity_rhs0");
 
  // Retrieve the primal and adjoint solutions at the current timestep
  retrieve_timestep();
 
  // Get f(t_j+1)
  _system.adjoint_qoi_parameter_sensitivity(qois, parameter_vector, sensitivities_right);
 
  // Remove the sensitivity rhs vector from system since we did not write it to file and it cannot be retrieved
  _system.remove_vector("sensitivity_rhs0");
 
  // Get the contributions for each sensitivity from this timestep
  const auto pv_size = parameter_vector.size();
  for (auto i : make_range(qois.size(_system)))
    for (auto j : make_range(pv_size))
      sensitivities[i][j] = ( (sensitivities_left[i][j] + sensitivities_right[i][j])/2. )*(time_right - time_left);
}

References libMesh::TimeSolver::_system, libMesh::ImplicitSystem::adjoint_qoi_parameter_sensitivity(), libMesh::DifferentiableSystem::deltat, libMesh::make_range(), libMesh::Real, libMesh::System::remove_vector(), libMesh::UnsteadySolver::retrieve_timestep(), libMesh::ParameterVector::size(), libMesh::QoISet::size(), and libMesh::System::time.

integrate_qoi_timestep()

void libMesh::Euler2Solver::integrate_qoi_timestep ( )

overridevirtual

A method to integrate the system::QoI functionals.

Implements libMesh::FirstOrderUnsteadySolver.

Definition at line 264 of file euler2_solver.C.

{
  // We use a numerical integration scheme consistent with the theta used for the timesolver.
 
  // Zero out the system.qoi vector
  for (auto j : make_range(_system.n_qois()))
  {
    _system.set_qoi(j, 0.0);
  }
 
  // Left and right side contributions
  std::vector<Number> left_contribution(_system.n_qois(), 0.0);
  Number time_left = 0.0;
  std::vector<Number> right_contribution(_system.n_qois(), 0.0);
  Number time_right = 0.0;
 
  time_left = _system.time;
 
  // Base class assumes a direct steady evaluation
  this->_system.assemble_qoi();
 
  // Also get the spatially integrated errors for all the QoIs in the QoI set
  for (auto j : make_range(_system.n_qois()))
  {
    left_contribution[j] = _system.get_qoi_value(j);
  }
 
  // Advance to t_j+1
  _system.time = _system.time + _system.deltat;
 
  time_right = _system.time;
 
  // Load the solution at the next timestep
  retrieve_timestep();
 
  // Zero out the system.qoi vector
  for (auto j : make_range(_system.n_qois()))
  {
    _system.set_qoi(j, 0.0);
  }
 
  // Base class assumes a direct steady evaluation
  this->_system.assemble_qoi();
 
  for(auto j : make_range(_system.n_qois()))
  {
    right_contribution[j] = _system.get_qoi_value(j);
  }
 
  // Combine the left and right side contributions as per the specified theta
  // theta = 0.5 (Crank-Nicholson) gives the trapezoidal rule.
  for (auto j : make_range(_system.n_qois()))
  {
    _system.set_qoi(j, ( ( ((1.0 - theta)*left_contribution[j]) + (theta*right_contribution[j]) )/2.0 )*(time_right - time_left));
  }
}

References libMesh::TimeSolver::_system, libMesh::ExplicitSystem::assemble_qoi(), libMesh::DifferentiableSystem::deltat, libMesh::System::get_qoi_value(), libMesh::make_range(), libMesh::System::n_qois(), libMesh::UnsteadySolver::retrieve_timestep(), libMesh::System::set_qoi(), theta, and libMesh::System::time.

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 277 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 194 of file unsteady_solver.h.

{ return false; }

last_completed_timestep_size()

Real libMesh::TimeSolver::last_completed_timestep_size ( )

virtualinherited

Returns system.deltat if fixed timestep solver is used, the complete timestep size (sum of all substeps) if the adaptive time solver is used.

Returns the change in system.time, deltat, for the last timestep which was successfully completed. This only returns the outermost step size in the case of nested time solvers. If no time step has yet been successfully completed, then returns system.deltat.

Reimplemented in libMesh::AdaptiveTimeSolver.

Definition at line 160 of file time_solver.C.

{
  return last_deltat;
}

References libMesh::TimeSolver::last_deltat.

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 225 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 85 of file reference_counter.h.

  { return _n_objects; }

References libMesh::ReferenceCounter::_n_objects.

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

nonlocal_residual()

bool libMesh::Euler2Solver::nonlocal_residual ( bool  request_jacobian, DiffContext &  context  )

overridevirtual

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

What combination it uses will depend on theta.

Implements libMesh::TimeSolver.

Definition at line 86 of file euler2_solver.C.

{
  bool compute_second_order_eqns = this->_system.have_second_order_scalar_vars();
 
  return this->_general_residual(request_jacobian,
                                 context,
                                 &DifferentiablePhysics::nonlocal_mass_residual,
                                 &DifferentiablePhysics::nonlocal_damping_residual,
                                 &DifferentiablePhysics::nonlocal_time_derivative,
                                 &DifferentiablePhysics::nonlocal_constraint,
                                 &DiffContext::nonlocal_reinit,
                                 compute_second_order_eqns);
}

References _general_residual(), libMesh::TimeSolver::_system, libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns(), libMesh::DifferentiableSystem::have_second_order_scalar_vars(), libMesh::DifferentiablePhysics::nonlocal_constraint(), libMesh::DifferentiablePhysics::nonlocal_damping_residual(), libMesh::DifferentiablePhysics::nonlocal_mass_residual(), libMesh::DiffContext::nonlocal_reinit(), and libMesh::DifferentiablePhysics::nonlocal_time_derivative().

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

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 26 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 _general_residual(), and libMesh::EulerSolver::_general_residual().

print_info()

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

staticinherited

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

Definition at line 81 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().

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

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::AdaptiveTimeSolver, and libMesh::SecondOrderUnsteadySolver.

Definition at line 104 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::AdaptiveTimeSolver, and libMesh::SecondOrderUnsteadySolver.

Definition at line 269 of file unsteady_solver.C.

{
  // Retrieve all the stored vectors at the current time
  solution_history->retrieve(false, _system.time);
 
  // 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, libMesh::TimeSolver::solution_history, and libMesh::System::time.

Referenced by integrate_adjoint_refinement_error_estimate(), libMesh::EulerSolver::integrate_adjoint_refinement_error_estimate(), libMesh::UnsteadySolver::integrate_adjoint_sensitivity(), integrate_qoi_timestep(), and libMesh::EulerSolver::integrate_qoi_timestep().

set_first_adjoint_step()

void libMesh::UnsteadySolver::set_first_adjoint_step ( bool  first_adjoint_step_setting )

inlineinherited

A setter for the first_adjoint_step boolean.

Needed for nested time solvers.

Definition at line 199 of file unsteady_solver.h.

  {
    first_adjoint_step = first_adjoint_step_setting;
  }

References libMesh::UnsteadySolver::first_adjoint_step.

set_first_solve()

void libMesh::UnsteadySolver::set_first_solve ( bool  first_solve_setting )

inlineinherited

Definition at line 209 of file unsteady_solver.h.

  {
    first_solve = first_solve_setting;
  }

References libMesh::UnsteadySolver::first_solve.

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 284 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 119 of file time_solver.C.

{
  solution_history = _solution_history.clone();
}

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

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

side_residual()

bool libMesh::Euler2Solver::side_residual ( bool  request_jacobian, DiffContext &  context  )

overridevirtual

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

What combination it uses will depend on theta.

Implements libMesh::TimeSolver.

Definition at line 71 of file euler2_solver.C.

{
  return this->_general_residual(request_jacobian,
                                 context,
                                 &DifferentiablePhysics::side_mass_residual,
                                 &DifferentiablePhysics::side_damping_residual,
                                 &DifferentiablePhysics::side_time_derivative,
                                 &DifferentiablePhysics::side_constraint,
                                 &DiffContext::elem_side_reinit,
                                 false);
}

References _general_residual(), libMesh::DiffContext::elem_side_reinit(), libMesh::DifferentiablePhysics::side_constraint(), libMesh::DifferentiablePhysics::side_damping_residual(), libMesh::DifferentiablePhysics::side_mass_residual(), and libMesh::DifferentiablePhysics::side_time_derivative().

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

Definition at line 127 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)
                {
                  // Set the successful deltat as the last deltat
                  last_deltat = _system.deltat;
 
                  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)
 
  // Set the successful deltat as the last deltat
  last_deltat = _system.deltat;
}

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::TimeSolver::last_deltat, 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 215 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 210 of file time_solver.h.

{ return _system; }

References libMesh::TimeSolver::_system.

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

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; }

update()

void libMesh::UnsteadySolver::update ( )

inherited

Definition at line 361 of file unsteady_solver.C.

{
  // 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(), and libMesh::UnsteadySolver::old_local_nonlinear_solution.

Member Data Documentation

_counts

ReferenceCounter::Counts libMesh::ReferenceCounter::_counts

staticprotectedinherited

Actually holds the data.

Definition at line 124 of file reference_counter.h.

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

_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 302 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 143 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 340 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 307 of file time_solver.h.

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

_mutex

Threads::spin_mutex libMesh::ReferenceCounter::_mutex

staticprotectedinherited

Mutual exclusion object to enable thread-safe reference counting.

Definition at line 137 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 132 of file reference_counter.h.

Referenced by libMesh::ReferenceCounter::n_objects(), libMesh::ReferenceCounter::ReferenceCounter(), libMesh::ReferenceCounter::ReferenceCounter(), 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 312 of file time_solver.h.

Referenced by libMesh::NewmarkSolver::_general_residual(), _general_residual(), libMesh::EulerSolver::_general_residual(), libMesh::SteadySolver::_general_residual(), libMesh::AdaptiveTimeSolver::adjoint_advance_timestep(), libMesh::UnsteadySolver::adjoint_advance_timestep(), libMesh::TimeSolver::adjoint_solve(), libMesh::TwostepTimeSolver::adjoint_solve(), libMesh::UnsteadySolver::adjoint_solve(), libMesh::AdaptiveTimeSolver::advance_timestep(), libMesh::NewmarkSolver::advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), libMesh::NewmarkSolver::compute_initial_accel(), libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns(), libMesh::UnsteadySolver::du(), libMesh::EigenTimeSolver::element_residual(), element_residual(), libMesh::EulerSolver::element_residual(), libMesh::TimeSolver::init(), libMesh::EigenTimeSolver::init(), libMesh::SecondOrderUnsteadySolver::init(), libMesh::UnsteadySolver::init(), libMesh::TimeSolver::init_adjoints(), libMesh::UnsteadySolver::init_adjoints(), libMesh::TimeSolver::init_data(), libMesh::SecondOrderUnsteadySolver::init_data(), libMesh::UnsteadySolver::init_data(), integrate_adjoint_refinement_error_estimate(), libMesh::EulerSolver::integrate_adjoint_refinement_error_estimate(), libMesh::SteadySolver::integrate_adjoint_refinement_error_estimate(), libMesh::TwostepTimeSolver::integrate_adjoint_refinement_error_estimate(), libMesh::SteadySolver::integrate_adjoint_sensitivity(), libMesh::TwostepTimeSolver::integrate_adjoint_sensitivity(), libMesh::UnsteadySolver::integrate_adjoint_sensitivity(), integrate_qoi_timestep(), libMesh::EulerSolver::integrate_qoi_timestep(), libMesh::SteadySolver::integrate_qoi_timestep(), libMesh::TwostepTimeSolver::integrate_qoi_timestep(), libMesh::EigenTimeSolver::nonlocal_residual(), nonlocal_residual(), libMesh::EulerSolver::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::TimeSolver::reinit(), libMesh::SecondOrderUnsteadySolver::reinit(), libMesh::UnsteadySolver::reinit(), libMesh::UnsteadySolver::retrieve_timestep(), libMesh::EigenTimeSolver::side_residual(), libMesh::EigenTimeSolver::solve(), libMesh::TwostepTimeSolver::solve(), libMesh::UnsteadySolver::solve(), libMesh::TimeSolver::system(), libMesh::TimeSolver::system(), and libMesh::UnsteadySolver::update().

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 226 of file unsteady_solver.h.

Referenced by libMesh::AdaptiveTimeSolver::adjoint_advance_timestep(), and libMesh::UnsteadySolver::set_first_adjoint_step().

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 220 of file unsteady_solver.h.

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

last_deltat

Real libMesh::TimeSolver::last_deltat

protectedinherited

The deltat for the last completed timestep before the current one.

Definition at line 332 of file time_solver.h.

Referenced by libMesh::TwostepTimeSolver::adjoint_solve(), libMesh::UnsteadySolver::adjoint_solve(), libMesh::TimeSolver::last_completed_timestep_size(), libMesh::TwostepTimeSolver::solve(), and libMesh::UnsteadySolver::solve().

last_step_deltat

Real libMesh::UnsteadySolver::last_step_deltat

protectedinherited

We will need to move the system.time around to ensure that residuals are built with the right deltat and the right time.

Definition at line 237 of file unsteady_solver.h.

Referenced by integrate_adjoint_refinement_error_estimate(), and libMesh::EulerSolver::integrate_adjoint_refinement_error_estimate().

next_step_deltat

Real libMesh::UnsteadySolver::next_step_deltat

protectedinherited

Definition at line 238 of file unsteady_solver.h.

Referenced by integrate_adjoint_refinement_error_estimate(), and libMesh::EulerSolver::integrate_adjoint_refinement_error_estimate().

old_adjoints

std::vector< std::unique_ptr<NumericVector<Number> > > libMesh::UnsteadySolver::old_adjoints

protectedinherited

A vector of pointers to vectors holding the adjoint solution at the last time step.

Definition at line 231 of file unsteady_solver.h.

Referenced by integrate_adjoint_refinement_error_estimate(), libMesh::EulerSolver::integrate_adjoint_refinement_error_estimate(), and libMesh::UnsteadySolver::UnsteadySolver().

old_local_nonlinear_solution

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

inherited

Serial vector of _system.get_vector("_old_nonlinear_solution") This is a shared_ptr so that it can be shared between different derived class instances, as in e.g.

AdaptiveTimeSolver.

Definition at line 178 of file unsteady_solver.h.

Referenced by libMesh::AdaptiveTimeSolver::adjoint_advance_timestep(), libMesh::UnsteadySolver::adjoint_advance_timestep(), libMesh::AdaptiveTimeSolver::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::UnsteadySolver::update().

quiet

bool libMesh::TimeSolver::quiet

inherited

Print extra debugging information if quiet == false.

Definition at line 230 of file time_solver.h.

Referenced by libMesh::EigenTimeSolver::solve(), libMesh::TwostepTimeSolver::solve(), and libMesh::UnsteadySolver::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 259 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 319 of file time_solver.h.

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

theta

Real libMesh::Euler2Solver::theta

The value for the theta method to employ: 1.0 corresponds to backwards Euler, 0.0 corresponds to forwards Euler, 0.5 corresponds to a Crank-Nicolson-like scheme.

Definition at line 122 of file euler2_solver.h.

Referenced by _general_residual(), error_order(), integrate_adjoint_refinement_error_estimate(), integrate_qoi_timestep(), and main().

---

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

• include/solvers/euler2_solver.h
• src/solvers/euler2_solver.C