LOCA::Bifurcation::PitchforkBord::StatusTest::SlackUpdateNorm Class Reference

A convergence test based on the update of the slack variable component for pitchfork location. More...

#include <LOCA_Bifurcation_PitchforkBord_SlackUpdateNorm.H>

Inheritance diagram for LOCA::Bifurcation::PitchforkBord::StatusTest::SlackUpdateNorm:

Collaboration diagram for LOCA::Bifurcation::PitchforkBord::StatusTest::SlackUpdateNorm:
List of all members.

Public Member Functions

 SlackUpdateNorm (double rtol, double atol, double tol)
virtual ~SlackUpdateNorm ()
virtual NOX::StatusTest::StatusType checkStatus (const NOX::Solver::Generic &problem)
 Evaluates convergence criteria specified above.
virtual NOX::StatusTest::StatusType getStatus () const
 Returns status as defined above.
virtual ostream & print (ostream &stream, int indent=0) const
 Prints current status.
double getSlackUpdateNorm () const
 Returns the value of weighted parameter update norm.
double getRTOL () const
 Returns the realative tolerance set in the constructor.
double getATOL () const
 Returns the absolute tolerance set in the constructor.
double getTOL () const
 Returns the tolerance set in the constructor.

Protected Attributes

double rtol
 Relative tolerance for convergence.
double atol
 Absolute tolerance for convergence.
double tol
 Tolerance for convergence.
double slackUpdateNorm
 Current value of the parameter update norm.
NOX::StatusTest::StatusType status
 Status of entire status test.

Detailed Description

A convergence test based on the update of the slack variable component for pitchfork location.

Let $\sigma$ be the pitchfork slack variable (see LOCA::Bifurcation::PitchforkBord::ExtendedGroup). This convergence test defines convergence for the slack variable when the following is true

\[ \frac{|\sigma-\sigma_0|}{\epsilon_r|\sigma| + \epsilon_a} < \tau \]

where $\sigma_0$ is the previous parameter value, $\epsilon_r$ is the relative tolerance, $\epsilon_a$ is the absolute tolerance, and $\tau$ is an overall scale factor (typically $\tau = 1$).

Note that this status test deals only with the slack component of the pitchfork equations. This status test should be combined with other status tests for the solution and null vector components (using NOX::StatusTest::Combo and LOCA::StatusTest::Wrapper) to build a composite status test for the entire system.

Also note that if the group returned by the getSolutionGroup() method of the solver supplied in checkStatus() is not a pitchfork group (i.e., not derived from LOCA::Bifurcation::Pitchforkbord::ExtendedGroup), checkStatus() returns NOX::StatusTest::Converged. This allows the status test to be used in situations other than pitchfork tracking, e.g., steady-state solves, without raising error conditions.

Constructor & Destructor Documentation

LOCA::Bifurcation::PitchforkBord::StatusTest::SlackUpdateNorm::SlackUpdateNorm double  rtol,
double  atol,
double  tol


rtol is the relative tolerance $\epsilon_r$, atol is the absolute tolerance $\epsilon_a$, and tol is the overall scale factor $\tau$ defined above.

The documentation for this class was generated from the following files:
Generated on Thu Sep 18 12:38:30 2008 for NOX by doxygen