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:

Public Member Functions
	Stagnation (int n=50, double tol=1.0)
	Constructor. More...

virtual	~Stagnation ()
	Destructor.

virtual NOX::StatusTest::StatusType	checkStatus (const NOX::Solver::Generic &problem, NOX::StatusTest::CheckType checkType)
	Tests the stopping criterion. More...

virtual NOX::StatusTest::StatusType	getStatus () const
	Return the result of the most recent checkStatus call.

virtual std::ostream &	print (std::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.

Public Member Functions inherited from NOX::StatusTest::Generic
	Generic ()
	Constructor.

virtual	~Generic ()
	Destructor.

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

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

References NOX::StatusTest::Unevaluated.

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.

References NOX::StatusTest::Failed, NOX::Abstract::Group::getNormF(), NOX::Solver::Generic::getNumIterations(), NOX::Solver::Generic::getPreviousSolutionGroup(), NOX::Solver::Generic::getSolutionGroup(), and NOX::StatusTest::Unconverged.

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

NOX_StatusTest_Stagnation.H
NOX_StatusTest_Stagnation.C

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation