Newton method to solve nonlinear equation of form: F(U) = U - b - R(U) = 0. U is the solution vector, b is a constant, and R(U) is some nonlinear function of U, which is computed in the ComputeRHS() Ops function. More...

#include <NewtonSolver.H>

Inheritance diagram for NewtonSolver< Vec, Ops >:

Public Member Functions
	NewtonSolver ()=default

	~NewtonSolver () override=default

	NewtonSolver (const NewtonSolver &)=delete

NewtonSolver &	operator= (const NewtonSolver &)=delete

	NewtonSolver (NewtonSolver &&) noexcept=delete

NewtonSolver &	operator= (NewtonSolver &&) noexcept=delete

void	Define (const Vec &a_U, Ops *a_ops) override
	Read user-provided parameters that control the nonlinear solver. Allocate intermediate data containers needed by the solver. For Newton, setup the linear solver for computing the Newton step.

void	Solve (Vec &a_U, const Vec &a_b, amrex::Real a_time, amrex::Real a_dt, int a_step) const override
	Solve the specified nonlinear equation for U. Picard: U = b + R(U). Newton: F(U) = U - b - R(U) = 0.

void	GetSolverParams (amrex::Real &a_rtol, amrex::Real &a_atol, int &a_maxits) override
	Return the convergence parameters used by the nonlinear solver.

void	CurTime (amrex::Real a_time) const

void	CurTimeStep (amrex::Real a_dt) const

void	PrintParams () const override
	Print parameters used by the nonlinear solver.

Public Member Functions inherited from NonlinearSolver< Vec, Ops >
	NonlinearSolver ()=default

virtual	~NonlinearSolver ()=default

	NonlinearSolver (const NonlinearSolver &)=delete

NonlinearSolver &	operator= (const NonlinearSolver &)=delete

	NonlinearSolver (NonlinearSolver &&) noexcept=delete

NonlinearSolver &	operator= (NonlinearSolver &&) noexcept=delete

bool	IsDefined () const
	Check if the nonlinear solver has been defined.

virtual bool	UsePreconditioner ()
	Whether a preconditioner is used by the nonlinear solver.

void	Verbose (bool a_verbose)
	Allow caller to dynamically change the verbosity flag. For example, one may want to only print solver information every 100 steps.

Private Member Functions
void	ParseParameters ()

void	EvalResidual (Vec &a_F, const Vec &a_U, const Vec &a_b, amrex::Real a_time, int a_iter) const
	Compute the nonlinear residual: F(U) = U - b - R(U).

Private Attributes
Vec	m_dU
	Intermediate Vec containers used by the solver.

Vec	m_F

Vec	m_R

Ops *	m_ops = nullptr
	Pointer to Ops class.

bool	m_require_convergence = true
	Flag to determine whether convergence is required.

amrex::Real	m_rtol = 1.0e-6
	Relative tolerance for the Newton solver.

amrex::Real	m_atol = 0.
	Absolute tolerance for the Newton solver.

int	m_maxits = 100
	Maximum iterations for the Newton solver.

int	m_total_iters = 0
	Total nonlinear iterations for the diagnostic file.

amrex::Real	m_linsol_rtol = 1.0e-4
	Relative tolerance for linear solver.

amrex::Real	m_linsol_atol = 0.
	Absolute tolerance for linear solver.

int	m_linsol_maxits = 1000
	Maximum iterations for linear solver.

int	m_total_linsol_iters = 0
	Total linear iterations for the diagnostic file.

int	m_linsol_verbose_int = 2
	Verbosity flag for linear solver.

int	m_linsol_restart_length = 30
	Restart iteration for linear solver.

PreconditionerType	m_pc_type = PreconditionerType::none
	Preconditioner type.

amrex::Real	m_cur_time

amrex::Real	m_dt

std::unique_ptr< JacobianFunctionMF< Vec, Ops > >	m_linear_function
	The linear function used by linear solver to compute A*v. In the contect of JFNK, A = dF/dU (i.e., system Jacobian)

LinearSolverType	m_linear_solver_type = LinearSolverType::amrex_gmres
	Choice of linear solver.

std::unique_ptr< LinearSolver< Vec, JacobianFunctionMF< Vec, Ops > > >	m_linear_solver
	The linear solver object.

Additional Inherited Members
Protected Attributes inherited from NonlinearSolver< Vec, Ops >
bool	m_is_defined = false

bool	m_verbose = true

std::string	m_diagnostic_file

int	m_diagnostic_interval = 1

bool	m_usePC = false

Detailed Description

template<class Vec, class Ops>
class NewtonSolver< Vec, Ops >

Newton method to solve nonlinear equation of form: F(U) = U - b - R(U) = 0. U is the solution vector, b is a constant, and R(U) is some nonlinear function of U, which is computed in the ComputeRHS() Ops function.

Constructor & Destructor Documentation

◆ NewtonSolver() [1/3]

template<class Vec, class Ops>

NewtonSolver< Vec, Ops >::NewtonSolver ( )

default

◆ ~NewtonSolver()

template<class Vec, class Ops>

NewtonSolver< Vec, Ops >::~NewtonSolver ( )

overridedefault

◆ NewtonSolver() [2/3]

template<class Vec, class Ops>

NewtonSolver< Vec, Ops >::NewtonSolver ( const NewtonSolver< Vec, Ops > & )

delete

◆ NewtonSolver() [3/3]

template<class Vec, class Ops>

NewtonSolver< Vec, Ops >::NewtonSolver ( NewtonSolver< Vec, Ops > && )

deletenoexcept

Member Function Documentation

◆ CurTime()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::CurTime ( amrex::Real a_time ) const

inline

◆ CurTimeStep()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::CurTimeStep ( amrex::Real a_dt ) const

inline

◆ Define()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::Define	(	const Vec &	,
		Ops *	)

overridevirtual

Read user-provided parameters that control the nonlinear solver. Allocate intermediate data containers needed by the solver. For Newton, setup the linear solver for computing the Newton step.

Implements NonlinearSolver< Vec, Ops >.

◆ EvalResidual()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::EvalResidual	(	Vec &	a_F,
		const Vec &	a_U,
		const Vec &	a_b,
		amrex::Real	a_time,
		int	a_iter ) const

private

Compute the nonlinear residual: F(U) = U - b - R(U).

◆ GetSolverParams()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::GetSolverParams	(	amrex::Real &	,
		amrex::Real &	,
		int &	)

inlineoverridevirtual

Return the convergence parameters used by the nonlinear solver.

Implements NonlinearSolver< Vec, Ops >.

◆ operator=() [1/2]

template<class Vec, class Ops>

NewtonSolver & NewtonSolver< Vec, Ops >::operator= ( const NewtonSolver< Vec, Ops > & )

delete

◆ operator=() [2/2]

template<class Vec, class Ops>

NewtonSolver & NewtonSolver< Vec, Ops >::operator= ( NewtonSolver< Vec, Ops > && )

deletenoexcept

◆ ParseParameters()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::ParseParameters ( )

private

◆ PrintParams()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::PrintParams ( ) const

inlineoverridevirtual

Print parameters used by the nonlinear solver.

Implements NonlinearSolver< Vec, Ops >.

◆ Solve()

template<class Vec, class Ops>

void NewtonSolver< Vec, Ops >::Solve	(	Vec &	,
		const Vec &	,
		amrex::Real	,
		amrex::Real	,
		int	) const

overridevirtual

Solve the specified nonlinear equation for U. Picard: U = b + R(U). Newton: F(U) = U - b - R(U) = 0.

Implements NonlinearSolver< Vec, Ops >.

Member Data Documentation

◆ m_atol

template<class Vec, class Ops>

amrex::Real NewtonSolver< Vec, Ops >::m_atol = 0.

private

Absolute tolerance for the Newton solver.

◆ m_cur_time

template<class Vec, class Ops>

amrex::Real NewtonSolver< Vec, Ops >::m_cur_time

mutableprivate

◆ m_dt

template<class Vec, class Ops>

amrex::Real NewtonSolver< Vec, Ops >::m_dt

private

◆ m_dU

template<class Vec, class Ops>

Vec NewtonSolver< Vec, Ops >::m_dU

mutableprivate

Intermediate Vec containers used by the solver.

◆ m_F

template<class Vec, class Ops>

Vec NewtonSolver< Vec, Ops >::m_F

private

◆ m_linear_function

template<class Vec, class Ops>

std::unique_ptr<JacobianFunctionMF<Vec,Ops> > NewtonSolver< Vec, Ops >::m_linear_function

private

The linear function used by linear solver to compute A*v. In the contect of JFNK, A = dF/dU (i.e., system Jacobian)

◆ m_linear_solver

template<class Vec, class Ops>

std::unique_ptr<LinearSolver<Vec,JacobianFunctionMF<Vec,Ops> > > NewtonSolver< Vec, Ops >::m_linear_solver

private

The linear solver object.

◆ m_linear_solver_type

template<class Vec, class Ops>

LinearSolverType NewtonSolver< Vec, Ops >::m_linear_solver_type = LinearSolverType::amrex_gmres

private

Choice of linear solver.

◆ m_linsol_atol

template<class Vec, class Ops>

amrex::Real NewtonSolver< Vec, Ops >::m_linsol_atol = 0.

private

Absolute tolerance for linear solver.

◆ m_linsol_maxits

template<class Vec, class Ops>

int NewtonSolver< Vec, Ops >::m_linsol_maxits = 1000

private

Maximum iterations for linear solver.

◆ m_linsol_restart_length

template<class Vec, class Ops>

int NewtonSolver< Vec, Ops >::m_linsol_restart_length = 30

private

Restart iteration for linear solver.

◆ m_linsol_rtol

template<class Vec, class Ops>

amrex::Real NewtonSolver< Vec, Ops >::m_linsol_rtol = 1.0e-4

private

Relative tolerance for linear solver.

◆ m_linsol_verbose_int

template<class Vec, class Ops>

int NewtonSolver< Vec, Ops >::m_linsol_verbose_int = 2

private

Verbosity flag for linear solver.

◆ m_maxits

template<class Vec, class Ops>

int NewtonSolver< Vec, Ops >::m_maxits = 100

private

Maximum iterations for the Newton solver.

◆ m_ops

template<class Vec, class Ops>

Ops* NewtonSolver< Vec, Ops >::m_ops = nullptr

private

Pointer to Ops class.

◆ m_pc_type

template<class Vec, class Ops>

PreconditionerType NewtonSolver< Vec, Ops >::m_pc_type = PreconditionerType::none

private

Preconditioner type.

◆ m_R

template<class Vec, class Ops>

Vec NewtonSolver< Vec, Ops >::m_R

private

◆ m_require_convergence

template<class Vec, class Ops>

bool NewtonSolver< Vec, Ops >::m_require_convergence = true

private

Flag to determine whether convergence is required.

◆ m_rtol

template<class Vec, class Ops>

amrex::Real NewtonSolver< Vec, Ops >::m_rtol = 1.0e-6

private

Relative tolerance for the Newton solver.

◆ m_total_iters

template<class Vec, class Ops>

int NewtonSolver< Vec, Ops >::m_total_iters = 0

mutableprivate

Total nonlinear iterations for the diagnostic file.

◆ m_total_linsol_iters

template<class Vec, class Ops>

int NewtonSolver< Vec, Ops >::m_total_linsol_iters = 0

mutableprivate

Total linear iterations for the diagnostic file.

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

/home/docs/checkouts/readthedocs.org/user_builds/warpx/checkouts/6270/Source/NonlinearSolvers/NewtonSolver.H

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ NewtonSolver() [1/3]

◆ ~NewtonSolver()

◆ NewtonSolver() [2/3]

◆ NewtonSolver() [3/3]

Member Function Documentation

◆ CurTime()

◆ CurTimeStep()

◆ Define()

◆ EvalResidual()

◆ GetSolverParams()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ ParseParameters()

◆ PrintParams()

◆ Solve()

Member Data Documentation

◆ m_atol

◆ m_cur_time

◆ m_dt

◆ m_dU

◆ m_F

◆ m_linear_function

◆ m_linear_solver

◆ m_linear_solver_type

◆ m_linsol_atol

◆ m_linsol_maxits

◆ m_linsol_restart_length

◆ m_linsol_rtol

◆ m_linsol_verbose_int

◆ m_maxits

◆ m_ops

◆ m_pc_type

◆ m_R

◆ m_require_convergence

◆ m_rtol

◆ m_total_iters

◆ m_total_linsol_iters