libMesh::EigenTimeSolver Class Reference

The name of this class is confusing...it's meant to refer to the base class (TimeSolver) while still telling one that it's for solving (generalized) EigenValue problems that arise from finite element discretizations. More...

#include <eigen_time_solver.h>

Inheritance diagram for libMesh::EigenTimeSolver:

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

Public Member Functions
	EigenTimeSolver (sys_type &s)
	Constructor. More...
virtual	~EigenTimeSolver ()
	Destructor. More...
virtual void	init () override
	The initialization function. More...
virtual void	reinit () override
	The reinitialization function. More...
virtual void	solve () override
	Implements the assembly of both matrices A and B, and calls the EigenSolver to compute the eigenvalues. More...
virtual void	advance_timestep () override
	It doesn't make sense to advance the timestep, so we shouldn't call this. More...
Real	error_order () const
	error convergence order against deltat is not applicable to an eigenvalue problem. More...
virtual bool	element_residual (bool get_jacobian, DiffContext &) override
	Forms either the spatial (Jacobian) or mass matrix part of the operator, depending on which is requested. More...
virtual bool	side_residual (bool get_jacobian, DiffContext &) override
	Forms the jacobian of the boundary terms. More...
virtual bool	nonlocal_residual (bool get_jacobian, DiffContext &) override
	Forms the jacobian of the nonlocal terms. More...
virtual Real	du (const SystemNorm &) const override
virtual bool	is_steady () const override
	This is effectively a steady-state solver. More...
virtual void	init_adjoints ()
	Initialize any adjoint related data structures, based on the number of qois. More...
virtual void	init_data ()
	The data initialization function. More...
virtual std::pair< unsigned int, Real >	adjoint_solve (const QoISet &qoi_indices)
	This method solves for the adjoint solution at the next adjoint timestep (or a steady state adjoint solve) More...
virtual void	adjoint_advance_timestep ()
	This method advances the adjoint solution to the previous timestep, after an adjoint_solve() has been performed. More...
virtual void	retrieve_timestep ()
	This method retrieves all the stored solutions at the current system.time. More...
virtual void	integrate_qoi_timestep ()
	A method to integrate the system::QoI functionals. More...
virtual void	integrate_adjoint_sensitivity (const QoISet &qois, const ParameterVector &parameter_vector, SensitivityData &sensitivities)
	A method to integrate the adjoint sensitivity w.r.t a given parameter vector. More...
virtual void	integrate_adjoint_refinement_error_estimate (AdjointRefinementEstimator &adjoint_refinement_error_estimator, ErrorVector &QoI_elementwise_error)
	A method to compute the adjoint refinement error estimate at the current timestep. 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...
SolutionHistory &	get_solution_history ()
	A getter function that returns a reference to the solution history object owned by TimeSolver. 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...
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. 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_stream=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< EigenSolver< Number > >	eigen_solver
	The EigenSolver object. More...
double	tol
	The linear solver tolerance to be used when solving the eigenvalue problem. More...
unsigned int	maxits
	The maximum number of iterations allowed to solve the problem. More...
unsigned int	n_eigenpairs_to_compute
	The number of eigenvectors/values to be computed. More...
unsigned int	n_basis_vectors_to_use
	The number of basis vectors to use in the computation. More...
unsigned int	n_converged_eigenpairs
	After a solve, holds the number of eigenpairs successfully converged. More...
unsigned int	n_iterations_reqd
	After a solve, holds the number of iterations required to converge the requested number of eigenpairs. More...
bool	quiet
	Print extra debugging information if quiet == false. More...
unsigned int	reduce_deltat_on_diffsolver_failure
	This value (which defaults to zero) is the number of times the TimeSolver is allowed to halve deltat and let the DiffSolver repeat the latest failed solve with a reduced timestep. More...

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

Protected Member Functions
void	increment_constructor_count (const std::string &name) noexcept
	Increments the construction counter. More...
void	increment_destructor_count (const std::string &name) noexcept
	Increments the destruction counter. More...

Protected Attributes
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...
Real	last_deltat
	The deltat for the last completed timestep before the current one. More...

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

Private Types
enum	NowAssembling { Matrix_A, Matrix_B, Invalid_Matrix }

Private Attributes
NowAssembling	now_assembling
	Flag which controls the internals of element_residual() and side_residual(). More...

Detailed Description

The name of this class is confusing...it's meant to refer to the base class (TimeSolver) while still telling one that it's for solving (generalized) EigenValue problems that arise from finite element discretizations.

For a time-dependent problem du/dt=F(u), with a steady solution 0=F(u_0), we look at the time evolution of a small perturbation, p=u-u_0, for which the (linearized) governing equation is

dp/dt = F'(u_0)p

where F'(u_0) is the Jacobian. The generalized eigenvalue problem arises by considering perturbations of the general form p = exp(lambda*t)x, which leads to

Ax = lambda*Bx

where A is the (discretized by FEM) Jacobian matrix and B is the (discretized by FEM) mass matrix.

The EigenSystem class (by Steffen Petersen) is related but does not fall under the FEMSystem paradigm invented by Roy Stogner. The EigenSolver class (also by Steffen) is meant to provide a generic "linear solver" interface for EigenValue software. The only current concrete implementation is a SLEPc-based eigensolver class, which we make use of here as well.

Author

John W. Peterson

Date

2007

Definition at line 66 of file eigen_time_solver.h.

Member Typedef Documentation

Counts

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

protectedinherited

Data structure to log the information.

The log is identified by the class name.

Definition at line 119 of file reference_counter.h.

Parent

typedef TimeSolver libMesh::EigenTimeSolver::Parent

The parent class.

Definition at line 77 of file eigen_time_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::EigenTimeSolver::sys_type

The type of system.

Definition at line 72 of file eigen_time_solver.h.

Member Enumeration Documentation

NowAssembling

enum libMesh::EigenTimeSolver::NowAssembling

private

Enumerator
Matrix_A	The matrix associated with the spatial part of the operator.
Matrix_B	The matrix associated with the time derivative (mass matrix).
Invalid_Matrix	The enum is in an invalid state.

Definition at line 198 of file eigen_time_solver.h.

                     {
    Matrix_A,

    Matrix_B,

    Invalid_Matrix
  };

Constructor & Destructor Documentation

EigenTimeSolver()

libMesh::EigenTimeSolver::EigenTimeSolver ( sys_type &  s )

explicit

Constructor.

Requires a reference to the system to be solved.

Definition at line 33 of file eigen_time_solver.C.

References eigen_solver, libMesh::GHEP, and libMesh::LARGEST_MAGNITUDE.

  : Parent(s),
    eigen_solver     (EigenSolver<Number>::build(s.comm())),
    tol(pow(TOLERANCE, 5./3.)),
    maxits(1000),
    n_eigenpairs_to_compute(5),
    n_basis_vectors_to_use(3*n_eigenpairs_to_compute),
    n_converged_eigenpairs(0),
    n_iterations_reqd(0)
{
  libmesh_experimental();
  eigen_solver->set_eigenproblem_type(GHEP);//or GNHEP
  eigen_solver->set_position_of_spectrum(LARGEST_MAGNITUDE);
}

~EigenTimeSolver()

libMesh::EigenTimeSolver::~EigenTimeSolver ( )

virtualdefault

Destructor.

Member Function Documentation

adjoint_advance_timestep()

void libMesh::TimeSolver::adjoint_advance_timestep ( )

virtualinherited

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

Definition at line 165 of file time_solver.C.

{
}

adjoint_solve()

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

virtualinherited

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

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

Definition at line 133 of file time_solver.C.

References libMesh::TimeSolver::_system, libMesh::TimeSolver::diff_solver(), libMesh::libmesh_assert(), and libMesh::TimeSolver::system().

{
  libmesh_assert(this->diff_solver().get());
  libmesh_assert_equal_to (&(this->diff_solver()->system()), &(this->system()));

  return this->_system.ImplicitSystem::adjoint_solve(qoi_indices);
}

advance_timestep()

virtual void libMesh::EigenTimeSolver::advance_timestep ( )

inlineoverridevirtual

It doesn't make sense to advance the timestep, so we shouldn't call this.

Reimplemented from libMesh::TimeSolver.

Definition at line 112 of file eigen_time_solver.h.

{}

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.

{}

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.

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().

{ return _diff_solver; }

disable_print_counter_info()

void libMesh::ReferenceCounter::disable_print_counter_info ( )

staticinherited

Definition at line 100 of file reference_counter.C.

References libMesh::ReferenceCounter::_enable_print_counter.

{
  _enable_print_counter = false;
  return;
}

du()

virtual Real libMesh::EigenTimeSolver::du ( const SystemNorm &  ) const

inlineoverridevirtual

Returns

0, but derived classes should override this function to compute the size of the difference between successive solution iterates ||u^{n+1} - u^{n}|| in some norm.

Implements libMesh::TimeSolver.

Definition at line 144 of file eigen_time_solver.h.

{ return 0.; }

element_residual()

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

overridevirtual

Forms either the spatial (Jacobian) or mass matrix part of the operator, depending on which is requested.

Implements libMesh::TimeSolver.

Definition at line 123 of file eigen_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::DiffContext::elem_solution_derivative, libMesh::DiffContext::elem_solution_rate_derivative, libMesh::DifferentiablePhysics::element_constraint(), libMesh::DifferentiablePhysics::element_time_derivative(), libMesh::DiffContext::get_elem_jacobian(), libMesh::DifferentiableSystem::get_physics(), libMesh::libmesh_assert(), libMesh::DifferentiablePhysics::mass_residual(), Matrix_A, Matrix_B, and now_assembling.

{
  // The EigenTimeSolver always computes jacobians!
  libmesh_assert (request_jacobian);

  context.elem_solution_rate_derivative = 1;
  context.elem_solution_derivative = 1;

  // Assemble the operator for the spatial part.
  if (now_assembling == Matrix_A)
    {
      bool jacobian_computed =
        _system.get_physics()->element_time_derivative(request_jacobian, context);

      // The user shouldn't compute a jacobian unless requested
      libmesh_assert(request_jacobian || !jacobian_computed);

      bool jacobian_computed2 =
        _system.get_physics()->element_constraint(jacobian_computed, context);

      // The user shouldn't compute a jacobian unless requested
      libmesh_assert (jacobian_computed || !jacobian_computed2);

      return jacobian_computed && jacobian_computed2;

    }

  // Assemble the mass matrix operator
  else if (now_assembling == Matrix_B)
    {
      bool mass_jacobian_computed =
        _system.get_physics()->mass_residual(request_jacobian, context);

      // Scale Jacobian by -1 to get positive matrix from new negative
      // mass_residual convention
      context.get_elem_jacobian() *= -1.0;

      return mass_jacobian_computed;
    }

  else
    libmesh_error_msg("Unrecognized value now_assembling = " << now_assembling);
}

enable_print_counter_info()

void libMesh::ReferenceCounter::enable_print_counter_info ( )

staticinherited

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

Definition at line 94 of file reference_counter.C.

References libMesh::ReferenceCounter::_enable_print_counter.

{
  _enable_print_counter = true;
  return;
}

error_order()

Real libMesh::EigenTimeSolver::error_order ( ) const

inline

error convergence order against deltat is not applicable to an eigenvalue problem.

Definition at line 118 of file eigen_time_solver.h.

{ return 0.; }

get_info()

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

staticinherited

Gets a string containing the reference information.

Definition at line 47 of file reference_counter.C.

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

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

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

  std::ostringstream oss;

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

  for (const auto & [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
}

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.

References libMesh::TimeSolver::solution_history.

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

{
  return *solution_history;
}

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.

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

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

{
  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();
  }
}

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.

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

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

{
  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();
  }
}

init()

void libMesh::EigenTimeSolver::init ( )

overridevirtual

The initialization function.

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

Reimplemented from libMesh::TimeSolver.

Definition at line 55 of file eigen_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::System::add_matrix(), and libMesh::System::have_matrix().

{
  // Add matrix "B" to _system if not already there.
  // The user may have already added a matrix "B" before
  // calling the System initialization.  This would be
  // necessary if e.g. the System originally started life
  // with a different type of TimeSolver and only later
  // had its TimeSolver changed to an EigenTimeSolver.
  if (!_system.have_matrix("B"))
    _system.add_matrix("B");
}

init_adjoints()

void libMesh::TimeSolver::init_adjoints ( )

virtualinherited

Initialize any adjoint related data structures, based on the number of qois.

Reimplemented in libMesh::UnsteadySolver.

Definition at line 83 of file time_solver.C.

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

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

{
  libmesh_assert_msg(_system.n_qois() != 0, "System qois have to be initialized before initializing adjoints.");

  // Add adjoint vectors
  for(auto i : make_range(_system.n_qois()))
  {
    std::string adjoint_solution_name = "adjoint_solution";
    adjoint_solution_name+= std::to_string(i);
    _system.add_vector(adjoint_solution_name, false, GHOSTED);
  }

}

init_data()

void libMesh::TimeSolver::init_data ( )

virtualinherited

The data initialization function.

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

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

Definition at line 97 of file time_solver.C.

References libMesh::TimeSolver::_system, libMesh::TimeSolver::diff_solver(), libMesh::TimeSolver::linear_solver(), libMesh::System::name(), and libMesh::on_command_line().

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

{
  this->diff_solver()->init();

  if (libMesh::on_command_line("--solver-system-names"))
    this->linear_solver()->init((_system.name()+"_").c_str());
  else
    this->linear_solver()->init();

  this->linear_solver()->init_names(_system);
}

integrate_adjoint_refinement_error_estimate()

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

virtualinherited

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. CURRENTLY ONLY SUPPORTED for Backward Euler.

Reimplemented in libMesh::UnsteadySolver, libMesh::SteadySolver, libMesh::EulerSolver, libMesh::FirstOrderUnsteadySolver, libMesh::TwostepTimeSolver, libMesh::AdaptiveTimeSolver, and libMesh::Euler2Solver.

Definition at line 153 of file time_solver.C.

{
  libmesh_not_implemented();
}

integrate_adjoint_sensitivity()

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

virtualinherited

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} ( / p) - ( R (u,z) / p ) dt

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

Definition at line 146 of file time_solver.C.

{
  libmesh_not_implemented();
}

integrate_qoi_timestep()

void libMesh::TimeSolver::integrate_qoi_timestep ( )

virtualinherited

A method to integrate the system::QoI functionals.

Reimplemented in libMesh::UnsteadySolver, libMesh::SteadySolver, libMesh::EulerSolver, libMesh::FirstOrderUnsteadySolver, libMesh::AdaptiveTimeSolver, libMesh::TwostepTimeSolver, and libMesh::Euler2Solver.

Definition at line 141 of file time_solver.C.

{
  libmesh_not_implemented();
}

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.

References libMesh::TimeSolver::_is_adjoint.

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

  { return _is_adjoint; }

is_steady()

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

inlineoverridevirtual

This is effectively a steady-state solver.

Implements libMesh::TimeSolver.

Definition at line 149 of file eigen_time_solver.h.

{ return true; }

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.

References libMesh::TimeSolver::last_deltat.

{
  return 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.

References libMesh::TimeSolver::_linear_solver.

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

{ return _linear_solver; }

n_objects()

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

inlinestaticinherited

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

Definition at line 85 of file reference_counter.h.

References libMesh::ReferenceCounter::_n_objects.

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

  { return _n_objects; }

nonlocal_residual()

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

overridevirtual

Forms the jacobian of the nonlocal terms.

Implements libMesh::TimeSolver.

Definition at line 217 of file eigen_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::DiffContext::get_elem_jacobian(), libMesh::DifferentiableSystem::get_physics(), libMesh::libmesh_assert(), Matrix_A, Matrix_B, libMesh::DifferentiablePhysics::nonlocal_constraint(), libMesh::DifferentiablePhysics::nonlocal_mass_residual(), libMesh::DifferentiablePhysics::nonlocal_time_derivative(), and now_assembling.

{
  // The EigenTimeSolver always requests jacobians?
  //libmesh_assert (request_jacobian);

  // Assemble the operator for the spatial part.
  if (now_assembling == Matrix_A)
    {
      bool jacobian_computed =
        _system.get_physics()->nonlocal_time_derivative(request_jacobian, context);

      // The user shouldn't compute a jacobian unless requested
      libmesh_assert (request_jacobian || !jacobian_computed);

      bool jacobian_computed2 =
        _system.get_physics()->nonlocal_constraint(jacobian_computed, context);

      // The user shouldn't compute a jacobian unless requested
      libmesh_assert (jacobian_computed || !jacobian_computed2);

      return jacobian_computed && jacobian_computed2;

    }

  // There is now a "side" equivalent for the mass matrix
  else if (now_assembling == Matrix_B)
    {
      bool mass_jacobian_computed =
        _system.get_physics()->nonlocal_mass_residual(request_jacobian, context);

      // Scale Jacobian by -1 to get positive matrix from new negative
      // mass_residual convention
      context.get_elem_jacobian() *= -1.0;

      return mass_jacobian_computed;
    }

  else
    libmesh_error_msg("Unrecognized value now_assembling = " << now_assembling);
}

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.

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

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

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

reinit()

void libMesh::EigenTimeSolver::reinit ( )

overridevirtual

The reinitialization function.

This method is used after changes in the mesh

Reimplemented from libMesh::TimeSolver.

Definition at line 50 of file eigen_time_solver.C.

{
  // empty...
}

retrieve_timestep()

void libMesh::TimeSolver::retrieve_timestep ( )

virtualinherited

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

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

Definition at line 169 of file time_solver.C.

{
}

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.

References libMesh::TimeSolver::_is_adjoint.

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

  { _is_adjoint = _is_adjoint_value; }

set_solution_history()

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

inherited

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

Definition at line 119 of file time_solver.C.

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

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

{
  solution_history = _solution_history.clone();
}

side_residual()

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

overridevirtual

Forms the jacobian of the boundary terms.

Implements libMesh::TimeSolver.

Definition at line 170 of file eigen_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::DiffContext::elem_solution_derivative, libMesh::DiffContext::elem_solution_rate_derivative, libMesh::DiffContext::get_elem_jacobian(), libMesh::DifferentiableSystem::get_physics(), libMesh::libmesh_assert(), Matrix_A, Matrix_B, now_assembling, libMesh::DifferentiablePhysics::side_constraint(), libMesh::DifferentiablePhysics::side_mass_residual(), and libMesh::DifferentiablePhysics::side_time_derivative().

{
  // The EigenTimeSolver always requests jacobians?
  //libmesh_assert (request_jacobian);

  context.elem_solution_rate_derivative = 1;
  context.elem_solution_derivative = 1;

  // Assemble the operator for the spatial part.
  if (now_assembling == Matrix_A)
    {
      bool jacobian_computed =
        _system.get_physics()->side_time_derivative(request_jacobian, context);

      // The user shouldn't compute a jacobian unless requested
      libmesh_assert (request_jacobian || !jacobian_computed);

      bool jacobian_computed2 =
        _system.get_physics()->side_constraint(jacobian_computed, context);

      // The user shouldn't compute a jacobian unless requested
      libmesh_assert (jacobian_computed || !jacobian_computed2);

      return jacobian_computed && jacobian_computed2;

    }

  // There is now a "side" equivalent for the mass matrix
  else if (now_assembling == Matrix_B)
    {
      bool mass_jacobian_computed =
        _system.get_physics()->side_mass_residual(request_jacobian, context);

      // Scale Jacobian by -1 to get positive matrix from new negative
      // mass_residual convention
      context.get_elem_jacobian() *= -1.0;

      return mass_jacobian_computed;
    }

  else
    libmesh_error_msg("Unrecognized value now_assembling = " << now_assembling);
}

solve()

void libMesh::EigenTimeSolver::solve ( )

overridevirtual

Implements the assembly of both matrices A and B, and calls the EigenSolver to compute the eigenvalues.

Reimplemented from libMesh::TimeSolver.

Definition at line 67 of file eigen_time_solver.C.

References libMesh::TimeSolver::_system, libMesh::DifferentiableSystem::assembly(), eigen_solver, libMesh::System::get_matrix(), libMesh::ImplicitSystem::get_system_matrix(), libMesh::ImplicitSystem::matrix, Matrix_A, Matrix_B, maxits, n_basis_vectors_to_use, n_converged_eigenpairs, n_eigenpairs_to_compute, n_iterations_reqd, now_assembling, libMesh::out, libMesh::TimeSolver::quiet, and tol.

{
  // The standard implementation is basically to call:
  // _diff_solver->solve();
  // which internally assembles (when necessary) matrices and vectors
  // and calls linear solver software while also doing Newton steps (see newton_solver.C)
  //
  // The element_residual and side_residual functions below control
  // what happens in the interior of the element assembly loops.
  // We have a system reference, so it's possible to call _system.assembly()
  // ourselves if we want to...
  //
  // Interestingly, for the EigenSolver we don't need residuals...just Jacobians.
  // The Jacobian should therefore always be requested, and always return
  // jacobian_computed as being true.

  // The basic plan of attack is:
  // .) Construct the Jacobian using _system.assembly(true,true) as we
  //    would for a steady system.  Use a flag in this class to
  //    control behavior in element_residual and side_residual
  // .) Swap _system.matrix to matrix "B" (be sure to add this extra matrix during init)
  // .) Call _system.assembly(true,true) again, using the flag in element_residual
  //    and side_residual to only get the mass matrix terms.
  // .) Send A and B to Steffen's EigenSolver interface.

  // Assemble the spatial part (matrix A) of the operator
  if (!this->quiet)
    libMesh::out << "Assembling matrix A." << std::endl;
  _system.matrix =   &( _system.get_system_matrix() );
  this->now_assembling = Matrix_A;
  _system.assembly(true, true);
  //_system.matrix->print_matlab("matrix_A.m");

  // Point the system's matrix at B, call assembly again.
  if (!this->quiet)
    libMesh::out << "Assembling matrix B." << std::endl;
  _system.matrix =   &( _system.get_matrix ("B") );
  this->now_assembling = Matrix_B;
  _system.assembly(true, true);
  //_system.matrix->print_matlab("matrix_B.m");

  // Send matrices A, B to Steffen's SlepcEigenSolver interface
  //libmesh_here();
  if (!this->quiet)
    libMesh::out << "Calling the EigenSolver." << std::endl;
  std::tie(this->n_converged_eigenpairs, this->n_iterations_reqd) =
    eigen_solver->solve_generalized (_system.get_system_matrix(),
                                     _system.get_matrix ("B"),
                                     n_eigenpairs_to_compute,
                                     n_basis_vectors_to_use,
                                     tol,
                                     maxits);
}

system() [1/2]

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.

References libMesh::TimeSolver::_system.

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

{ return _system; }

system() [2/2]

sys_type& libMesh::TimeSolver::system ( )

inlineinherited

Returns

A writable reference to the system we are solving.

Definition at line 215 of file time_solver.h.

References libMesh::TimeSolver::_system.

{ return _system; }

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().

_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(), 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::EulerSolver::_general_residual(), libMesh::Euler2Solver::_general_residual(), libMesh::SteadySolver::_general_residual(), libMesh::NewmarkSolver::_general_residual(), libMesh::AdaptiveTimeSolver::adjoint_advance_timestep(), libMesh::UnsteadySolver::adjoint_advance_timestep(), libMesh::TwostepTimeSolver::adjoint_solve(), libMesh::UnsteadySolver::adjoint_solve(), libMesh::TimeSolver::adjoint_solve(), libMesh::NewmarkSolver::advance_timestep(), libMesh::AdaptiveTimeSolver::advance_timestep(), libMesh::UnsteadySolver::advance_timestep(), libMesh::NewmarkSolver::compute_initial_accel(), libMesh::FirstOrderUnsteadySolver::compute_second_order_eqns(), libMesh::UnsteadySolver::du(), libMesh::EulerSolver::element_residual(), libMesh::Euler2Solver::element_residual(), element_residual(), libMesh::SecondOrderUnsteadySolver::init(), libMesh::UnsteadySolver::init(), libMesh::TimeSolver::init(), init(), libMesh::UnsteadySolver::init_adjoints(), libMesh::TimeSolver::init_adjoints(), libMesh::SecondOrderUnsteadySolver::init_data(), libMesh::UnsteadySolver::init_data(), libMesh::TimeSolver::init_data(), libMesh::Euler2Solver::integrate_adjoint_refinement_error_estimate(), libMesh::TwostepTimeSolver::integrate_adjoint_refinement_error_estimate(), libMesh::EulerSolver::integrate_adjoint_refinement_error_estimate(), libMesh::TwostepTimeSolver::integrate_adjoint_sensitivity(), libMesh::SteadySolver::integrate_adjoint_sensitivity(), libMesh::UnsteadySolver::integrate_adjoint_sensitivity(), libMesh::Euler2Solver::integrate_qoi_timestep(), libMesh::TwostepTimeSolver::integrate_qoi_timestep(), libMesh::EulerSolver::integrate_qoi_timestep(), libMesh::SteadySolver::integrate_qoi_timestep(), libMesh::EulerSolver::nonlocal_residual(), libMesh::Euler2Solver::nonlocal_residual(), nonlocal_residual(), libMesh::UnsteadySolver::old_nonlinear_solution(), libMesh::SecondOrderUnsteadySolver::old_solution_accel(), libMesh::SecondOrderUnsteadySolver::old_solution_rate(), libMesh::NewmarkSolver::project_initial_accel(), libMesh::SecondOrderUnsteadySolver::project_initial_rate(), libMesh::SecondOrderUnsteadySolver::reinit(), libMesh::UnsteadySolver::reinit(), libMesh::TimeSolver::reinit(), libMesh::UnsteadySolver::retrieve_timestep(), side_residual(), libMesh::TwostepTimeSolver::solve(), libMesh::UnsteadySolver::solve(), solve(), libMesh::TimeSolver::system(), and libMesh::UnsteadySolver::update().

eigen_solver

std::unique_ptr<EigenSolver<Number> > libMesh::EigenTimeSolver::eigen_solver

The EigenSolver object.

This is what actually makes the calls to SLEPc.

Definition at line 155 of file eigen_time_solver.h.

Referenced by EigenTimeSolver(), and 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().

maxits

unsigned int libMesh::EigenTimeSolver::maxits

The maximum number of iterations allowed to solve the problem.

Definition at line 166 of file eigen_time_solver.h.

Referenced by solve().

n_basis_vectors_to_use

unsigned int libMesh::EigenTimeSolver::n_basis_vectors_to_use

The number of basis vectors to use in the computation.

According to ex16, the number of basis vectors must be >= the number of eigenpairs requested, and ncv >= 2*nev is recommended. Increasing this number, even by a little bit, can greatly reduce the number of (EigenSolver) iterations required to compute the desired number of eigenpairs, but the cost per iteration goes up drastically as well.

Definition at line 182 of file eigen_time_solver.h.

Referenced by solve().

n_converged_eigenpairs

unsigned int libMesh::EigenTimeSolver::n_converged_eigenpairs

After a solve, holds the number of eigenpairs successfully converged.

Definition at line 188 of file eigen_time_solver.h.

Referenced by solve().

n_eigenpairs_to_compute

unsigned int libMesh::EigenTimeSolver::n_eigenpairs_to_compute

The number of eigenvectors/values to be computed.

Definition at line 171 of file eigen_time_solver.h.

Referenced by solve().

n_iterations_reqd

unsigned int libMesh::EigenTimeSolver::n_iterations_reqd

After a solve, holds the number of iterations required to converge the requested number of eigenpairs.

Definition at line 194 of file eigen_time_solver.h.

Referenced by solve().

now_assembling

NowAssembling libMesh::EigenTimeSolver::now_assembling

private

Flag which controls the internals of element_residual() and side_residual().

Definition at line 218 of file eigen_time_solver.h.

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

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::TwostepTimeSolver::solve(), libMesh::UnsteadySolver::solve(), and 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().

tol

double libMesh::EigenTimeSolver::tol

The linear solver tolerance to be used when solving the eigenvalue problem.

FIXME: need more info...

Definition at line 161 of file eigen_time_solver.h.

Referenced by solve().

---

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

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