Nonlinear solver based on a line search (i.e., damping). More...

#include <NOX_Solver_LineSearchBased.H>

Inheritance diagram for NOX::Solver::LineSearchBased:

Collaboration diagram for NOX::Solver::LineSearchBased:

Public Member Functions
	LineSearchBased (const Teuchos::RCP< NOX::Abstract::Group > &grp, const Teuchos::RCP< NOX::StatusTest::Generic > &tests, const Teuchos::RCP< Teuchos::ParameterList > &params)
	Constructor.
virtual	~LineSearchBased ()
	Destructor.
virtual void	reset (const NOX::Abstract::Vector &initialGuess, const Teuchos::RCP< NOX::StatusTest::Generic > &tests)
	Resets the solver, sets a new status test, and sets a new initial guess.
virtual void	reset (const NOX::Abstract::Vector &initialGuess)
	Resets the solver and sets a new initial guess.
virtual void	reset ()
	Resets the solver for another solve. This resets the counters and status only. Uses the final solution from the last solve as the initial guess for the next solve.
virtual NOX::StatusTest::StatusType	step ()
	Do one nonlinear step in the iteration sequence and return status.
virtual NOX::StatusTest::StatusType	solve ()
	Solve the nonlinear problem and return final status.
virtual const NOX::Abstract::Group &	getSolutionGroup () const
	Return a reference to the current solution group.
virtual const NOX::Abstract::Group &	getPreviousSolutionGroup () const
	Return a reference to the previous solution group.
virtual NOX::StatusTest::StatusType	getStatus () const
	Returns the current status of the solver.
virtual int	getNumIterations () const
	Get number of iterations.
virtual const Teuchos::ParameterList &	getList () const
	Return a reference to the solver parameters.
virtual double	getStepSize () const
virtual Teuchos::RCP< const NOX::Abstract::Group >	getSolutionGroupPtr () const
	Return a RCP to the solution group.
virtual Teuchos::RCP< const NOX::Abstract::Group >	getPreviousSolutionGroupPtr () const
	Return a RCP to the previous solution group.
virtual Teuchos::RCP< const Teuchos::ParameterList >	getListPtr () const
	Return a RCP to the solver parameters.
virtual Teuchos::RCP< const NOX::SolverStats >	getSolverStatistics () const
	Return a RCP to the solver statistics.
Public Member Functions inherited from NOX::Solver::Generic
	Generic ()
	Constructor (does nothing).
virtual	~Generic ()
	Destructor (does nothing).

Protected Member Functions
virtual void	init ()
	Print out initialization information and calcuation the RHS.
virtual void	printUpdate ()
	Prints the current iteration information.

Protected Attributes
Teuchos::RCP< NOX::GlobalData >	globalDataPtr
	Pointer to the global data object.
Teuchos::RCP< NOX::Utils >	utilsPtr
	Utils.
Teuchos::RCP< NOX::Abstract::Group >	solnPtr
	Current solution.
Teuchos::RCP< NOX::Abstract::Group >	oldSolnPtr
	Previous solution pointer.
Teuchos::RCP< NOX::Abstract::Vector >	dirPtr
	Current search direction pointer.
Teuchos::RCP< NOX::StatusTest::Generic >	testPtr
	Stopping test.
Teuchos::RCP< Teuchos::ParameterList >	paramsPtr
	Input parameters.
Teuchos::RCP< NOX::LineSearch::Generic >	lineSearchPtr
	Linesearch.
Teuchos::RCP< NOX::Direction::Generic >	directionPtr
	Search Direction.
double	stepSize
	Current step.
int	nIter
	Number of nonlinear iterations.
bool	catchThrowsDuringSolve
	Determine if we want to catch and ignore exceptions thrown from the linear solver stack.
NOX::StatusTest::StatusType	status
	Status of nonlinear solver.
NOX::StatusTest::CheckType	checkType
	Type of check to use for status tests. See NOX::StatusTest for more details.
Teuchos::RCP< NOX::Observer >	observer
	Pointer to a user defined NOX::Observer object.

Detailed Description

Nonlinear solver based on a line search (i.e., damping).

Solves $ F(x)=0$ using an iterative line-search-based method.

Each iteration, the solver does the following.

Compute a search direction via a NOX::Direction method
Compute a step length $\lambda$ and update as $x_{\rm new} = x_{\rm old} + \lambda d$ via a NOX::LineSearch method.

The iterations progress until the status tests (see NOX::StatusTest) determine either failure or convergence.

Note: To support several line searches and status tests, this version of the solver has a getStepSize() function that returns $\lambda$ .

Input Parameters

The following parameter list entries are valid for this solver:

"Line Search" - Sublist of the line search parameters, passed to the NOX::LineSearch::Manager constructor. Defaults to an empty list.
"Direction" - Sublist of the direction parameters, passed to the NOX::Direction::Manager constructor. Defaults to an empty list.
"Solver Options" - Sublist of general solver options.
- "User Defined Pre/Post Operator" is supported. See NOX::Parameter::PrePostOperator for more details.

Output Parameters

Every time solve() is called, a sublist for output parameters called "Output" will be created and contain the following parameters.

"Output":

"Nonlinear Iterations" - Number of nonlinear iterations
"2-Norm of Residual" - Two-norm of final residual

Author: Tammy Kolda (SNL 8950), Roger Pawlowski (SNL 9233)

Constructor & Destructor Documentation

◆ LineSearchBased()

NOX::Solver::LineSearchBased::LineSearchBased	(	const Teuchos::RCP< NOX::Abstract::Group > &	grp,
		const Teuchos::RCP< NOX::StatusTest::Generic > &	tests,
		const Teuchos::RCP< Teuchos::ParameterList > &	params )

Constructor.

See reset(NOX::Abstract::Group&, NOX::StatusTest::Generic&, Teuchos::ParameterList&) for description

References NOX::DeepCopy, dirPtr, globalDataPtr, init(), observer, oldSolnPtr, paramsPtr, NOX::Solver::parseObserver(), NOX::ShapeCopy, solnPtr, testPtr, utilsPtr, and NOX::Solver::validateSolverOptionsSublist().

Member Function Documentation

◆ getList()

const Teuchos::ParameterList & NOX::Solver::LineSearchBased::getList ( ) const

virtual

Return a reference to the solver parameters.

Implements NOX::Solver::Generic.

References paramsPtr.

◆ getListPtr()

virtual Teuchos::RCP< const Teuchos::ParameterList > NOX::Solver::LineSearchBased::getListPtr ( ) const

inlinevirtual

Return a RCP to the solver parameters.

Implements NOX::Solver::Generic.

References paramsPtr.

◆ getNumIterations()

int NOX::Solver::LineSearchBased::getNumIterations ( ) const

virtual

Get number of iterations.

Implements NOX::Solver::Generic.

References nIter.

Referenced by NOX::Direction::Broyden::compute().

◆ getPreviousSolutionGroup()

const NOX::Abstract::Group & NOX::Solver::LineSearchBased::getPreviousSolutionGroup ( ) const

virtual

Return a reference to the previous solution group.

Implements NOX::Solver::Generic.

References oldSolnPtr.

Referenced by NOX::Direction::Broyden::compute().

◆ getPreviousSolutionGroupPtr()

virtual Teuchos::RCP< const NOX::Abstract::Group > NOX::Solver::LineSearchBased::getPreviousSolutionGroupPtr ( ) const

inlinevirtual

Return a RCP to the previous solution group.

Implements NOX::Solver::Generic.

References oldSolnPtr.

◆ getSolutionGroup()

const NOX::Abstract::Group & NOX::Solver::LineSearchBased::getSolutionGroup ( ) const

virtual

Return a reference to the current solution group.

Implements NOX::Solver::Generic.

References solnPtr.

◆ getSolutionGroupPtr()

virtual Teuchos::RCP< const NOX::Abstract::Group > NOX::Solver::LineSearchBased::getSolutionGroupPtr ( ) const

inlinevirtual

Return a RCP to the solution group.

Implements NOX::Solver::Generic.

References solnPtr.

◆ getSolverStatistics()

Teuchos::RCP< const NOX::SolverStats > NOX::Solver::LineSearchBased::getSolverStatistics ( ) const

virtual

Return a RCP to the solver statistics.

Implements NOX::Solver::Generic.

References globalDataPtr.

◆ getStatus()

NOX::StatusTest::StatusType NOX::Solver::LineSearchBased::getStatus ( ) const

virtual

Returns the current status of the solver.

Implements NOX::Solver::Generic.

References status.

◆ init()

void NOX::Solver::LineSearchBased::init ( )

protectedvirtual

Print out initialization information and calcuation the RHS.

References catchThrowsDuringSolve, checkType, directionPtr, NOX::Utils::fill(), globalDataPtr, lineSearchPtr, nIter, NOX::Utils::Parameters, paramsPtr, NOX::Solver::parseStatusTestCheckType(), status, stepSize, NOX::StatusTest::Unconverged, and utilsPtr.

Referenced by LineSearchBased().

◆ printUpdate()

void NOX::Solver::LineSearchBased::printUpdate ( )

protectedvirtual

Prints the current iteration information.

References NOX::StatusTest::Converged, dirPtr, NOX::StatusTest::Failed, NOX::Utils::fill(), nIter, NOX::Utils::OuterIteration, NOX::Utils::OuterIterationStatusTest, solnPtr, status, stepSize, testPtr, NOX::StatusTest::Unconverged, and utilsPtr.

Referenced by step().

◆ reset() [1/3]

void NOX::Solver::LineSearchBased::reset ( )

virtual

Resets the solver for another solve. This resets the counters and status only. Uses the final solution from the last solve as the initial guess for the next solve.

NOTE: All NOX solvers will call reset() automatically at teh beginning of the solve() method. We add the reset() method to the solver interface for the application to call in case the application needs to reset counters and status manually before the next call to solve() is made.

Implements NOX::Solver::Generic.

References globalDataPtr, nIter, status, stepSize, and NOX::StatusTest::Unconverged.