#include <NewtonSolver.h>

Inheritance diagram for dolfin::NewtonSolver:

Collaboration diagram for dolfin::NewtonSolver:

Public Member Functions
	NewtonSolver (MPI_Comm comm=MPI_COMM_WORLD)
	Create nonlinear solver.

	NewtonSolver (MPI_Comm comm, std::shared_ptr< GenericLinearSolver > solver, GenericLinearAlgebraFactory &factory)

virtual	~NewtonSolver ()
	Destructor.

std::pair< std::size_t, bool >	solve (NonlinearProblem &nonlinear_function, GenericVector &x)

std::size_t	iteration () const

std::size_t	krylov_iterations () const

double	residual () const

double	residual0 () const

double	relative_residual () const

GenericLinearSolver &	linear_solver () const

void	set_relaxation_parameter (double relaxation_parameter)

double	get_relaxation_parameter ()

Public Member Functions inherited from dolfin::Variable
	Variable ()
	Create unnamed variable.

	Variable (const std::string name, const std::string label)
	Create variable with given name and label.

	Variable (const Variable &variable)
	Copy constructor.

virtual	~Variable ()
	Destructor.

const Variable &	operator= (const Variable &variable)
	Assignment operator.

void	rename (const std::string name, const std::string label)
	Rename variable.

std::string	name () const
	Return name.

std::string	label () const
	Return label (description)

std::size_t	id () const

virtual std::string	str (bool verbose) const
	Return informal string representation (pretty-print)

Static Public Member Functions
static Parameters	default_parameters ()

Protected Member Functions
virtual bool	converged (const GenericVector &r, const NonlinearProblem &nonlinear_problem, std::size_t iteration)

virtual void	solver_setup (std::shared_ptr< const GenericMatrix > A, std::shared_ptr< const GenericMatrix > P, const NonlinearProblem &nonlinear_problem, std::size_t iteration)

virtual void	update_solution (GenericVector &x, const GenericVector &dx, double relaxation_parameter, const NonlinearProblem &nonlinear_problem, std::size_t iteration)

Additional Inherited Members
Public Attributes inherited from dolfin::Variable
Parameters	parameters
	Parameters.

Detailed Description

This class defines a Newton solver for nonlinear systems of equations of the form :math:F(x) = 0.

Constructor & Destructor Documentation

◆ NewtonSolver()

NewtonSolver::NewtonSolver	(	MPI_Comm	comm,
		std::shared_ptr< GenericLinearSolver >	solver,
		GenericLinearAlgebraFactory &	factory
	)

Create nonlinear solver using provided linear solver

Arguments comm (MPI_Ccmm) The MPI communicator. solver (GenericLinearSolver) The linear solver. factory (GenericLinearAlgebraFactory) The factory.

Member Function Documentation

◆ converged()

bool NewtonSolver::converged	(	const GenericVector &	r,
		const NonlinearProblem &	nonlinear_problem,
		std::size_t	iteration
	)

protectedvirtual

Convergence test. It may be overloaded using virtual inheritance and this base criterion may be called from derived, both in C++ and Python.

Arguments r (GenericVector) Residual for criterion evaluation. nonlinear_problem (NonlinearProblem) The nonlinear problem. iteration (std::size_t) Newton iteration number.

Returns bool Whether convergence occurred.

◆ default_parameters()

Parameters NewtonSolver::default_parameters ( )

static

Default parameter values

Returns Parameters Parameter values.

◆ get_relaxation_parameter()

double dolfin::NewtonSolver::get_relaxation_parameter ( )

inline

Get relaxation parameter

Returns double Relaxation parameter value.

◆ iteration()

std::size_t NewtonSolver::iteration ( ) const

Return current Newton iteration number

Returns std::size_t The iteration number.

◆ krylov_iterations()

std::size_t NewtonSolver::krylov_iterations ( ) const

Return number of Krylov iterations elapsed since solve started

Returns std::size_t The number of iterations.

◆ linear_solver()

GenericLinearSolver & NewtonSolver::linear_solver ( ) const

Return the linear solver

Returns GenericLinearSolver The linear solver.

◆ relative_residual()

double NewtonSolver::relative_residual ( ) const

Return current relative residual

Returns double Current relative residual.

◆ residual()

double NewtonSolver::residual ( ) const

Return current residual

Returns double Current residual.

◆ residual0()

double NewtonSolver::residual0 ( ) const

Return initial residual

Returns double Initial residual.

◆ set_relaxation_parameter()

void dolfin::NewtonSolver::set_relaxation_parameter ( double relaxation_parameter )

inline

Set relaxation parameter. Default value 1.0 means full Newton method, value smaller than 1.0 relaxes the method by shrinking effective Newton step size by the given factor.

Arguments relaxation_parameter(double) Relaxation parameter value.

◆ solve()

std::pair< std::size_t, bool > NewtonSolver::solve	(	NonlinearProblem &	nonlinear_function,
		GenericVector &	x
	)

Solve abstract nonlinear problem :math:F(x) = 0 for given :math:F and Jacobian :math:\dfrac{\partial F}{\partial x}.

Arguments nonlinear_function (NonlinearProblem) The nonlinear problem. x (GenericVector) The vector.

Returns std::pair<std::size_t, bool> Pair of number of Newton iterations, and whether iteration converged)

◆ solver_setup()

void NewtonSolver::solver_setup	(	std::shared_ptr< const GenericMatrix >	A,
		std::shared_ptr< const GenericMatrix >	P,
		const NonlinearProblem &	nonlinear_problem,
		std::size_t	iteration
	)

protectedvirtual

Setup solver to be used with system matrix A and preconditioner matrix P. It may be overloaded to get finer control over linear solver setup, various linesearch tricks, etc. Note that minimal implementation should call set_operators method of the linear solver.

Arguments A (std::shared_ptr<const GenericMatrix>) System Jacobian matrix. J (std::shared_ptr<const GenericMatrix>) System preconditioner matrix. nonlinear_problem (NonlinearProblem) The nonlinear problem. iteration (std::size_t) Newton iteration number.

◆ update_solution()

void NewtonSolver::update_solution	(	GenericVector &	x,
		const GenericVector &	dx,
		double	relaxation_parameter,
		const NonlinearProblem &	nonlinear_problem,
		std::size_t	iteration
	)

protectedvirtual

Update solution vector by computed Newton step. Default update is given by formula::

x -= relaxation_parameter*dx

Arguments x (GenericVector>) The solution vector to be updated. dx (GenericVector>) The update vector computed by Newton step. relaxation_parameter (double) Newton relaxation parameter. nonlinear_problem (NonlinearProblem) The nonlinear problem. iteration (std::size_t) Newton iteration number.

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

/home/fenics/shared/dolfin/dolfin/nls/NewtonSolver.h
/home/fenics/shared/dolfin/dolfin/nls/NewtonSolver.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ NewtonSolver()

Member Function Documentation

◆ converged()

◆ default_parameters()

◆ get_relaxation_parameter()

◆ iteration()

◆ krylov_iterations()

◆ linear_solver()

◆ relative_residual()

◆ residual()

◆ residual0()

◆ set_relaxation_parameter()

◆ solve()

◆ solver_setup()

◆ update_solution()