NOX::StatusTest::Stagnation Class Reference

Failure test based on the convergence rate between nonlinear iterations. More...

#include <NOX_StatusTest_Stagnation.H>

Inheritance diagram for NOX::StatusTest::Stagnation:

Collaboration diagram for NOX::StatusTest::Stagnation:

List of all members.

Public Member Functions

Stagnation (int n=50, double tol=1.0)

Constructor.

virtual ~Stagnation ()

Destructor.

virtual NOX::StatusTest::StatusType checkStatus (const NOX::Solver::Generic &problem, NOX::StatusTest::CheckType checkType)

Tests the stopping criterion.

virtual NOX::StatusTest::StatusType getStatus () const

Return the result of the most recent checkStatus call.

virtual ostream & print (ostream &stream, int indent=0) const

Output formatted description of stopping test to output stream.

virtual int getMaxNumSteps () const

Returns the used specified number of steps that can consecutively fail the tolerance test before the test returns a failed status.

virtual int getCurrentNumSteps () const

Returns the current number of steps that have consecutively failed the tolerance test.

virtual double getTolerance () const

Returns the user specified tolerance.

virtual double getConvRate () const

Returns the current convergence rate.

Private Attributes

int maxSteps

User supplied value of n.

int numSteps

Current number of consecutive nonlinear iterations that have failed the specified tolerance.

int lastIteration

The last nonlinear iteration index.

double tolerance

User specified tolerance.

double convRate

Currently computed convergence rate.

NOX::StatusTest::StatusType status

Status

Detailed Description

Failure test based on the convergence rate between nonlinear iterations.

This status test returns NOX::StatusTest::Failed if we fail to reduce the norm of $F$ by a specified tolerance for n consecutive iterations. In other words, if

$\frac{\| F_k \|}{\| F_{k-1} \|} \geq {\rm tolerance}$

for n consecutive iterations, the status is set to NOX::StatusTest::Failed and returned. Otherwise, the status is set to NOX::StatusTest::Uncoverged and returned. Both n and the tolerance are specified in the constructor, by n and tol, respectively.

Based on experience the following values are recommended:

For Newton solves: n = 50, tolerance = 1.0
For Newton solves with a line search: n = 15, tolerance = 0.99

Definition at line 81 of file NOX_StatusTest_Stagnation.H.

Constructor & Destructor Documentation

NOX::StatusTest::Stagnation::Stagnation	(	int	n = `50`,
		double	tol = `1.0`
	)

Constructor.

Parameters:

	n	- Number of consecutive nonlinear iterations
	tol	- Tolerance for stagnation test

Definition at line 47 of file NOX_StatusTest_Stagnation.C.

References NOX::StatusTest::Unevaluated.

NOX::StatusTest::Stagnation::~Stagnation ( ) [virtual]

Destructor.

Definition at line 58 of file NOX_StatusTest_Stagnation.C.

Member Function Documentation

NOX::StatusTest::StatusType NOX::StatusTest::Stagnation::checkStatus	(	const NOX::Solver::Generic &	problem,
		NOX::StatusTest::CheckType	checkType
	)			`[virtual]`

Tests the stopping criterion.

Note:: The nature of this test is such that it must be executed at every nonlinear iteration, so we don't use the checkType argument.

Implements NOX::StatusTest::Generic.

Definition at line 64 of file NOX_StatusTest_Stagnation.C.

References convRate, NOX::StatusTest::Failed, NOX::Abstract::Group::getNormF(), NOX::Solver::Generic::getNumIterations(), NOX::Solver::Generic::getPreviousSolutionGroup(), NOX::Solver::Generic::getSolutionGroup(), lastIteration, maxSteps, numSteps, status, tolerance, and NOX::StatusTest::Unconverged.

NOX::StatusTest::StatusType NOX::StatusTest::Stagnation::getStatus ( ) const [virtual]

Return the result of the most recent checkStatus call.

Implements NOX::StatusTest::Generic.

Definition at line 110 of file NOX_StatusTest_Stagnation.C.

References status.

ostream & NOX::StatusTest::Stagnation::print	(	ostream &	stream,
		int	indent = `0`
	)			const `[virtual]`

Output formatted description of stopping test to output stream.

Implements NOX::StatusTest::Generic.

Definition at line 115 of file NOX_StatusTest_Stagnation.C.

References convRate, maxSteps, numSteps, and status.

int NOX::StatusTest::Stagnation::getMaxNumSteps ( ) const [virtual]

Returns the used specified number of steps that can consecutively fail the tolerance test before the test returns a failed status.

Definition at line 130 of file NOX_StatusTest_Stagnation.C.

References maxSteps.

int NOX::StatusTest::Stagnation::getCurrentNumSteps ( ) const [virtual]

Returns the current number of steps that have consecutively failed the tolerance test.

Definition at line 135 of file NOX_StatusTest_Stagnation.C.

References numSteps.

double NOX::StatusTest::Stagnation::getTolerance ( ) const [virtual]

Returns the user specified tolerance.

Definition at line 140 of file NOX_StatusTest_Stagnation.C.

References tolerance.

double NOX::StatusTest::Stagnation::getConvRate ( ) const [virtual]

Returns the current convergence rate.

Definition at line 145 of file NOX_StatusTest_Stagnation.C.

References convRate.

Member Data Documentation

int NOX::StatusTest::Stagnation::maxSteps [private]

User supplied value of n.

Definition at line 129 of file NOX_StatusTest_Stagnation.H.

Referenced by checkStatus(), getMaxNumSteps(), and print().

int NOX::StatusTest::Stagnation::numSteps [private]

Current number of consecutive nonlinear iterations that have failed the specified tolerance.

Definition at line 132 of file NOX_StatusTest_Stagnation.H.

Referenced by checkStatus(), getCurrentNumSteps(), and print().

int NOX::StatusTest::Stagnation::lastIteration [private]

The last nonlinear iteration index.

This is used to prevent counting a step multiple times if by chance the status test is called multiple times between iterations.

Definition at line 138 of file NOX_StatusTest_Stagnation.H.

Referenced by checkStatus().

double NOX::StatusTest::Stagnation::tolerance [private]

User specified tolerance.

Definition at line 141 of file NOX_StatusTest_Stagnation.H.

Referenced by checkStatus(), and getTolerance().

double NOX::StatusTest::Stagnation::convRate [private]

Currently computed convergence rate.

Definition at line 144 of file NOX_StatusTest_Stagnation.H.

Referenced by checkStatus(), getConvRate(), and print().

NOX::StatusTest::StatusType NOX::StatusTest::Stagnation::status [private]

Status

Definition at line 147 of file NOX_StatusTest_Stagnation.H.

Referenced by checkStatus(), getStatus(), and print().

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


Public Member Functions
	Stagnation (int n=50, double tol=1.0)
	Constructor.
virtual	~Stagnation ()
	Destructor.
virtual NOX::StatusTest::StatusType	checkStatus (const NOX::Solver::Generic &problem, NOX::StatusTest::CheckType checkType)
	Tests the stopping criterion.
virtual NOX::StatusTest::StatusType	getStatus () const
	Return the result of the most recent checkStatus call.
virtual ostream &	print (ostream &stream, int indent=0) const
	Output formatted description of stopping test to output stream.
virtual int	getMaxNumSteps () const
	Returns the used specified number of steps that can consecutively fail the tolerance test before the test returns a failed status.
virtual int	getCurrentNumSteps () const
	Returns the current number of steps that have consecutively failed the tolerance test.
virtual double	getTolerance () const
	Returns the user specified tolerance.
virtual double	getConvRate () const
	Returns the current convergence rate.
Private Attributes
int	maxSteps
	User supplied value of n.
int	numSteps
	Current number of consecutive nonlinear iterations that have failed the specified tolerance.
int	lastIteration
	The last nonlinear iteration index.
double	tolerance
	User specified tolerance.
double	convRate
	Currently computed convergence rate.
NOX::StatusTest::StatusType	status
	Status