NOX::StatusTest::NormF Class Reference

Various convergence tests based on the norm of the residual. More...

#include <NOX_StatusTest_NormF.H>

Inheritance diagram for NOX::StatusTest::NormF:

[legend]Collaboration diagram for NOX::StatusTest::NormF:[legend]List of all members.


Public Types
enum	ScaleType { Unscaled, Scaled }
	Type that determines whether to scale the norm by the problem size. More...
enum	ToleranceType { Relative, Absolute }
	Type that determines whether the norm is absolute or relative to the intial guess. More...
Public Member Functions
	NormF (double tolerance, NOX::Abstract::Vector::NormType ntype, ScaleType stype=Scaled)
	Constructor for absolute norm.
	NormF (double tolerance, ScaleType stype=Scaled)
	Constructor for absolute norm.
	NormF (NOX::Abstract::Group &initialGuess, double tolerance, NOX::Abstract::Vector::NormType ntype, ScaleType stype=Scaled)
	Constructor with initial guess (for relative norms).
	NormF (NOX::Abstract::Group &initialGuess, double tolerance, ScaleType stype=Scaled)
	Constructor with initial guess (for relative norms).
virtual	~NormF ()
	Destructor.
virtual NOX::StatusTest::StatusType	checkStatus (const NOX::Solver::Generic &problem)
	Test the stopping criterion
virtual NOX::StatusTest::StatusType	checkStatusEfficiently (const NOX::Solver::Generic &problem, NOX::StatusTest::CheckType checkType)
	Test the stopping criterion efficiently
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 double	getNormF () const
	Returns the value of the F-norm computed in the last call to checkStatus.
virtual double	getTrueTolerance () const
	Returns the true tolerance.
virtual double	getSpecifiedTolerance () const
	Returns the specified tolerance set in the constructor.
virtual double	getInitialTolerance () const
	Returns the initial tolerance.

Detailed Description

Various convergence tests based on the norm of the residual.

Use the constructor to define the test based on the type of scaling (see ScaleType) and the type of Tolerance (see Tolerance).

If checkStatus is called with the type set to NOX::StatusTest::None, then the status is set to NOX::StatusTest::Unevaluated and returned. (Also #normF is set to 0.0.)

If checkStatus is called on a problem where the solution group does not have F evaluated (i.e., problem.getSolutionGroup().isF() is false), then the status is set to NOX::StatusTest::Unconverged and returned. (Also #normF is set to -1.0.)

Finally, we return NOX::StatusTest::Converged if $\alpha < \beta$ , and NOX::StatusTest::Unconverged otherwise. Here $\alpha$ represents the norm of $F(x)$ and $\beta$ represents the tolerance, as described below.

Let $\gamma$ denote an optional scale factor defined as

$\gamma = \frac{1}{n}$ if sType in the constructor is NOX::NormF::Scaled, and

Then $\alpha$ is defined as follows:

If nType in the constructor is Abstract::Vector::TWO, then
$\alpha = \sqrt{ \gamma \sum_{i=1}^n F_i^2 }$

If nType in the constructor is Abstract::Vector::ONE, then
$\alpha = \gamma \sum_{i=1}^n | F_i |$

If nType in the constructor is Abstract::Vector::INF, then
$\alpha = \gamma \max_{i} | F_i |$

We set $\beta$ as follows, based on the value of tolerance in the constructor.

If an initial guess is provided, we use a relative tolerance defined by
$\beta = \frac{\mbox{tolerance}}{\alpha_0}$
Here $\alpha_0$ is the $\alpha$ (as defined above) associated with the initial guess.

Otherwise, we use an absolute tolerance defined by
$\beta = \mbox{tolerance}$

Member Enumeration Documentation

enum NOX::StatusTest::NormF::ScaleType

Type that determines whether to scale the norm by the problem size.

Enumeration values:

Unscaled No norm scaling.

Scaled Scale the norm by the length of the vector.

enum NOX::StatusTest::NormF::ToleranceType

Type that determines whether the norm is absolute or relative to the intial guess.

Enumeration values:

Relative Relative to starting guess.

Absolute Absolute.

Constructor & Destructor Documentation

NOX::StatusTest::NormF::NormF ( double tolerance,

NOX::Abstract::Vector::NormType ntype,

ScaleType stype = Scaled

)

Constructor for absolute norm.
This constructor defaults to the Absolute tolerance type.

NOX::StatusTest::NormF::NormF ( double tolerance,

ScaleType stype = Scaled

)

Constructor for absolute norm.
This constructor defaults to the Absolute ToleranceType and TWO NormType.

NOX::StatusTest::NormF::NormF ( NOX::Abstract::Group & initialGuess,

double tolerance,

NOX::Abstract::Vector::NormType ntype,

ScaleType stype = Scaled

)

Constructor with initial guess (for relative norms).
This constructor defaults to the Relative tolerance type.

NOX::StatusTest::NormF::NormF ( NOX::Abstract::Group & initialGuess,

double tolerance,

ScaleType stype = Scaled

)

Constructor with initial guess (for relative norms).
This constructor defaults to the Relative ToleranceType and TWO NormType.

Member Function Documentation

NOX::StatusTest::StatusType NOX::StatusTest::NormF::checkStatusEfficiently ( const NOX::Solver::Generic & problem,

NOX::StatusTest::CheckType checkType

) [virtual]

Test the stopping criterion efficiently
The test can (and should, if possible) be skipped if checkType is NOX::StatusType::None. If the test is skipped, then the status should be set to NOX::StatusTest::Unevaluated.
Reimplemented from NOX::StatusTest::Generic.

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

NOX_StatusTest_NormF.H
NOX_StatusTest_NormF.C

Generated on Thu Sep 18 12:40:52 2008 for NOX by

1.3.9.1

NOX::StatusTest::NormF Class Reference

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation