libMesh

This class wraps another UnsteadySolver derived class, and compares the results of timestepping with deltat and timestepping with 2*deltat to adjust future timestep lengths. More...
#include <twostep_time_solver.h>
Public Types  
typedef AdaptiveTimeSolver  Parent 
The parent class. More...  
typedef DifferentiableSystem  sys_type 
The type of system. More...  
Public Member Functions  
TwostepTimeSolver (sys_type &s)  
Constructor. More...  
~TwostepTimeSolver ()  
Destructor. More...  
virtual void  solve () override 
This method solves for the solution at the next timestep. More...  
virtual void  init () override 
The initialization function. More...  
virtual void  reinit () override 
The reinitialization function. More...  
virtual void  advance_timestep () override 
This method advances the solution to the next timestep, after a solve() has been performed. More...  
virtual Real  error_order () const override 
This method is passed on to the core_time_solver. More...  
virtual bool  element_residual (bool get_jacobian, DiffContext &) override 
This method is passed on to the core_time_solver. More...  
virtual bool  side_residual (bool get_jacobian, DiffContext &) override 
This method is passed on to the core_time_solver. More...  
virtual bool  nonlocal_residual (bool get_jacobian, DiffContext &) override 
This method is passed on to the core_time_solver. More...  
virtual std::unique_ptr< DiffSolver > &  diff_solver () override 
An implicit linear or nonlinear solver to use at each timestep. More...  
virtual std::unique_ptr< LinearSolver< Number > > &  linear_solver () override 
An implicit linear solver to use for adjoint and sensitivity problems. More...  
virtual unsigned int  time_order () const override 
virtual void  init_data () override 
The data initialization function. 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...  
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 steadystate solver. 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 () 
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< UnsteadySolver >  core_time_solver 
This object is used to take timesteps. More...  
SystemNorm  component_norm 
Error calculations are done in this norm, DISCRETE_L2 by default. More...  
std::vector< float >  component_scale 
If component_norms is nonempty, each variable's contribution to the error of a system will also be scaled by component_scale[var], unless component_scale is empty in which case all variables will be weighted equally. More...  
Real  target_tolerance 
This tolerance is the target relative error between an exact time integration and a single time step output, scaled by deltat. More...  
Real  upper_tolerance 
This tolerance is the maximum relative error between an exact time integration and a single time step output, scaled by deltat. More...  
Real  max_deltat 
Do not allow the adaptive time solver to select deltat > max_deltat. More...  
Real  min_deltat 
Do not allow the adaptive time solver to select deltat < min_deltat. More...  
Real  max_growth 
Do not allow the adaptive time solver to select a new deltat greater than max_growth times the old deltat. More...  
bool  global_tolerance 
This flag, which is true by default, grows (shrinks) the timestep based on the expected global accuracy of the timestepping scheme. More...  
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  
virtual Real  calculate_norm (System &, NumericVector< Number > &) 
A helper function to calculate error norms. More...  
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  
Real  last_deltat 
We need to store the value of the last deltat used, so that advance_timestep() will increment the system time correctly. More...  
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 threadsafe reference counting. More...  
static bool  _enable_print_counter 
Flag to control whether reference count information is printed when print_info is called. More...  
This class wraps another UnsteadySolver derived class, and compares the results of timestepping with deltat and timestepping with 2*deltat to adjust future timestep lengths.
Currently this class only works on fully coupled Systems
This class is part of the new DifferentiableSystem framework, which is still experimental. Users of this framework should beware of bugs and future API changes.
Definition at line 50 of file twostep_time_solver.h.

protectedinherited 
Data structure to log the information.
The log is identified by the class name.
Definition at line 117 of file reference_counter.h.
The parent class.
Definition at line 56 of file twostep_time_solver.h.

protectedinherited 
Definition at line 273 of file time_solver.h.

protectedinherited 
Definitions of argument types for use in refactoring subclasses.
Definition at line 271 of file time_solver.h.

inherited 
The type of system.
Definition at line 65 of file time_solver.h.

explicit 
Constructor.
Requires a reference to the system to be solved.
libMesh::TwostepTimeSolver::~TwostepTimeSolver  (  ) 
Destructor.

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.

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

virtualinherited 
This method is for subclasses or users to override to do arbitrary processing between timesteps.
Definition at line 167 of file time_solver.h.

protectedvirtualinherited 
A helper function to calculate error norms.

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

overridevirtualinherited 
An implicit linear or nonlinear solver to use at each timestep.
Reimplemented from libMesh::TimeSolver.

staticinherited 

overridevirtualinherited 
Computes the size of u^{n+1}  u^{n} in some norm.
Implements libMesh::TimeSolver.

overridevirtualinherited 
This method is passed on to the core_time_solver.
Implements libMesh::TimeSolver.

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

overridevirtualinherited 
This method is passed on to the core_time_solver.
Implements libMesh::UnsteadySolver.

staticinherited 
Gets a string containing the reference information.

protectedinherited 
Increments the construction counter.
Should be called in the constructor of any derived class that will be reference counted.
Definition at line 181 of file reference_counter.h.
References libMesh::ReferenceCounter::_counts, libMesh::Quality::name(), and libMesh::Threads::spin_mtx.
Referenced by libMesh::ReferenceCountedObject< RBParametrized >::ReferenceCountedObject().

protectedinherited 
Increments the destruction counter.
Should be called in the destructor of any derived class that will be reference counted.
Definition at line 194 of file reference_counter.h.
References libMesh::ReferenceCounter::_counts, libMesh::Quality::name(), and libMesh::Threads::spin_mtx.
Referenced by libMesh::ReferenceCountedObject< RBParametrized >::~ReferenceCountedObject().

overridevirtualinherited 
The initialization function.
This method is used to initialize internal data structures before a simulation begins.
Reimplemented from libMesh::UnsteadySolver.

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.

inherited 
Accessor for querying whether we need to do a primal or adjoint solve.
Definition at line 233 of file time_solver.h.
References libMesh::TimeSolver::_is_adjoint.

overridevirtualinherited 
This is not a steadystate solver.
Implements libMesh::TimeSolver.
Definition at line 154 of file unsteady_solver.h.

overridevirtualinherited 
An implicit linear solver to use for adjoint and sensitivity problems.
Reimplemented from libMesh::TimeSolver.

staticinherited 
Prints the number of outstanding (created, but not yet destroyed) objects.
Definition at line 83 of file reference_counter.h.
References libMesh::ReferenceCounter::_n_objects.

overridevirtualinherited 
This method is passed on to the core_time_solver.
Implements libMesh::TimeSolver.

inherited 

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.

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

overridevirtualinherited 
The reinitialization function.
This method is used to resize internal data vectors after a mesh change.
Reimplemented from libMesh::UnsteadySolver.

overridevirtualinherited 
This method retrieves all the stored solutions at the current system.time.
Reimplemented from libMesh::TimeSolver.
Reimplemented in libMesh::SecondOrderUnsteadySolver.

inherited 
Accessor for setting whether we need to do a primal or adjoint solve.
Definition at line 240 of file time_solver.h.
References libMesh::TimeSolver::_is_adjoint.

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

overridevirtualinherited 
This method is passed on to the core_time_solver.
Implements libMesh::TimeSolver.

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

inherited 
Definition at line 172 of file time_solver.h.
References libMesh::TimeSolver::_system.

inherited 
Definition at line 177 of file time_solver.h.
References libMesh::TimeSolver::_system.

overridevirtualinherited 
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.

staticprotectedinherited 
Actually holds the data.
Definition at line 122 of file reference_counter.h.
Referenced by libMesh::ReferenceCounter::increment_constructor_count(), and libMesh::ReferenceCounter::increment_destructor_count().

protectedinherited 
An implicit linear or nonlinear solver to use at each timestep.
Definition at line 248 of file time_solver.h.
Referenced by libMesh::TimeSolver::diff_solver().

staticprotectedinherited 
Flag to control whether reference count information is printed when print_info is called.
Definition at line 141 of file reference_counter.h.

protectedinherited 
An implicit linear solver to use for adjoint problems.
Definition at line 253 of file time_solver.h.
Referenced by libMesh::TimeSolver::linear_solver().

staticprotectedinherited 
Mutual exclusion object to enable threadsafe reference counting.
Definition at line 135 of file reference_counter.h.

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().

protectedinherited 
A reference to the system we are solving.
Definition at line 258 of file time_solver.h.
Referenced by libMesh::TimeSolver::system().

inherited 
Error calculations are done in this norm, DISCRETE_L2 by default.
Definition at line 119 of file adaptive_time_solver.h.

inherited 
If component_norms is nonempty, each variable's contribution to the error of a system will also be scaled by component_scale[var], unless component_scale is empty in which case all variables will be weighted equally.
Definition at line 127 of file adaptive_time_solver.h.

inherited 
This object is used to take timesteps.
Definition at line 114 of file adaptive_time_solver.h.

protectedinherited 
A bool that will be true the first time adjoint_advance_timestep() is called, (when the primal solution is to be used to set adjoint boundary conditions) and false thereafter.
Definition at line 168 of file unsteady_solver.h.

protectedinherited 
A bool that will be true the first time solve() is called, and false thereafter.
Definition at line 162 of file unsteady_solver.h.

inherited 
This flag, which is true by default, grows (shrinks) the timestep based on the expected global accuracy of the timestepping scheme.
Global in this sense means the cumulative finaltime accuracy of the scheme. For example, the backward Euler scheme's truncation error is locally of order 2, so that after N timesteps of size deltat, the result is firstorder accurate. If you set this to false, you can grow (shrink) your timestep based on the local accuracy rather than the global accuracy of the core TimeSolver.
Definition at line 198 of file adaptive_time_solver.h.

protectedinherited 
We need to store the value of the last deltat used, so that advance_timestep() will increment the system time correctly.
Definition at line 207 of file adaptive_time_solver.h.

inherited 
Do not allow the adaptive time solver to select deltat > max_deltat.
If you use the default max_deltat=0.0, then deltat is unlimited.
Definition at line 167 of file adaptive_time_solver.h.

inherited 
Do not allow the adaptive time solver to select a new deltat greater than max_growth times the old deltat.
If you use the default max_growth=0.0, then the deltat growth is unlimited.
Definition at line 181 of file adaptive_time_solver.h.

inherited 
Do not allow the adaptive time solver to select deltat < min_deltat.
The default value is 0.0.
Definition at line 173 of file adaptive_time_solver.h.

inherited 
Serial vector of _system.get_vector("_old_nonlinear_solution")
Definition at line 138 of file unsteady_solver.h.

inherited 
Print extra debugging information if quiet == false.
Definition at line 192 of file time_solver.h.

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.
Definition at line 221 of file time_solver.h.

protectedinherited 
A std::unique_ptr to a SolutionHistory object.
Default is NoSolutionHistory, which the user can override by declaring a different kind of SolutionHistory in the application
Definition at line 265 of file time_solver.h.

inherited 
This tolerance is the target relative error between an exact time integration and a single time step output, scaled by deltat.
integrator, scaled by deltat. If the estimated error exceeds or undershoots the target error tolerance, future timesteps will be run with deltat shrunk or grown to compensate.
The default value is 1.0e2; obviously users should select their own tolerance.
If a negative target_tolerance is specified, then its absolute value is used to scale the estimated error from the first simulation time step, and this becomes the target tolerance of all future time steps.
Definition at line 144 of file adaptive_time_solver.h.

inherited 
This tolerance is the maximum relative error between an exact time integration and a single time step output, scaled by deltat.
If this error tolerance is exceeded by the estimated error of the current time step, that time step will be repeated with a smaller deltat.
If you use the default upper_tolerance=0.0, then the current time step will not be repeated regardless of estimated error.
If a negative upper_tolerance is specified, then its absolute value is used to scale the estimated error from the first simulation time step, and this becomes the upper tolerance of all future time steps.
Definition at line 161 of file adaptive_time_solver.h.