libMesh

This class defines a thetamethod (defaulting to Backward Euler with theta = 1.0) solver to handle time integration of DifferentiableSystems. More...
#include <euler2_solver.h>
Public Types  
typedef FirstOrderUnsteadySolver  Parent 
The parent class. More...  
typedef DifferentiableSystem  sys_type 
The type of system. More...  
Public Member Functions  
Euler2Solver (sys_type &s)  
Constructor. More...  
virtual  ~Euler2Solver () 
Destructor. More...  
virtual Real  error_order () const override 
Error convergence order: 2 for CrankNicolson, 1 otherwise. More...  
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. More...  
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. More...  
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 nonlocal terms. More...  
virtual unsigned int  time_order () const override 
virtual void  init () override 
The initialization function. More...  
virtual void  init_data () override 
The data initialization function. More...  
virtual void  reinit () override 
The reinitialization function. More...  
virtual void  solve () override 
This method solves for the solution at the next timestep. More...  
virtual void  advance_timestep () override 
This method advances the solution to the next timestep, after a solve() has been performed. More...  
virtual void  adjoint_advance_timestep () override 
This method advances the adjoint solution to the previous timestep, after an adjoint_solve() has been performed. More...  
virtual void  retrieve_timestep () override 
This method retrieves all the stored solutions at the current system.time. More...  
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 () 
virtual std::unique_ptr< DiffSolver > &  diff_solver () 
An implicit linear or nonlinear solver to use at each timestep. More...  
virtual std::unique_ptr< LinearSolver< Number > > &  linear_solver () 
An implicit linear solver to use for adjoint and sensitivity problems. More...  
void  set_solution_history (const SolutionHistory &_solution_history) 
A setter function users will employ if they need to do something other than save no solution history. More...  
bool  is_adjoint () const 
Accessor for querying whether we need to do a primal or adjoint solve. More...  
void  set_is_adjoint (bool _is_adjoint_value) 
Accessor for setting whether we need to do a primal or adjoint solve. More...  
Static Public Member Functions  
static std::string  get_info () 
Gets a string containing the reference information. More...  
static void  print_info (std::ostream &out=libMesh::out) 
Prints the reference information, by default to libMesh::out . More...  
static unsigned int  n_objects () 
Prints the number of outstanding (created, but not yet destroyed) objects. More...  
static void  enable_print_counter_info () 
Methods to enable/disable the reference counter output from print_info() More...  
static void  disable_print_counter_info () 
Public Attributes  
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 CrankNicolsonlike 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 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. 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  
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 defines a thetamethod (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 + (1theta)*u_old), Euler2 solves m(u') = theta*f(u_new) + (1theta)*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.
Definition at line 48 of file euler2_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 54 of file euler2_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.

virtual 
Destructor.

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

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

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.

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.

virtualinherited 
An implicit linear or nonlinear solver to use at each timestep.
Reimplemented in libMesh::AdaptiveTimeSolver.
Definition at line 182 of file time_solver.h.
References libMesh::TimeSolver::_diff_solver.

staticinherited 

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

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.

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

overridevirtual 
Error convergence order: 2 for CrankNicolson, 1 otherwise.
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::TimeSolver.
Reimplemented in libMesh::AdaptiveTimeSolver, and libMesh::SecondOrderUnsteadySolver.

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.

virtualinherited 
An implicit linear solver to use for adjoint and sensitivity problems.
Reimplemented in libMesh::AdaptiveTimeSolver.
Definition at line 187 of file time_solver.h.
References libMesh::TimeSolver::_linear_solver.

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.

overridevirtual 
This method uses the DifferentiablePhysics' nonlocal_time_derivative() and nonlocal_constraint() to build a full residual for nonlocal terms.
What combination it uses will depend on theta.
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::TimeSolver.
Reimplemented in libMesh::SecondOrderUnsteadySolver, and libMesh::AdaptiveTimeSolver.

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.

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.

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::AdaptiveTimeSolver, and libMesh::TwostepTimeSolver.

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().

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 
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.
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 CrankNicolsonlike scheme.
Definition at line 105 of file euler2_solver.h.