NOX::Solver::LineSearchBased Class Reference

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

#include <NOX_Solver_LineSearchBased.H>

Inheritance diagram for NOX::Solver::LineSearchBased:

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Collaboration diagram for NOX::Solver::LineSearchBased:
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List of all members.

Public Member Functions

 LineSearchBased (NOX::Abstract::Group &grp, NOX::StatusTest::Generic &tests, NOX::Parameter::List &params)
 Constructor.
virtual ~LineSearchBased ()
 Destructor.
virtual bool reset (NOX::Abstract::Group &grp, NOX::StatusTest::Generic &tests, NOX::Parameter::List &params)
 Reset the nonlinear solver for a new solve.
virtual bool reset (NOX::Abstract::Group &grp, NOX::StatusTest::Generic &tests)
 A soft reset of the nonlinear solver for a new problem.
virtual NOX::StatusTest::StatusType getStatus ()
 Check current convergence and failure status.
virtual NOX::StatusTest::StatusType iterate ()
 Do one nonlinear method iteration and return status.
virtual NOX::StatusTest::StatusType solve ()
 Solve the nonlinear problem and return final status.
virtual const NOX::Abstract::GroupgetSolutionGroup () const
 Return a reference to the current solution group.
virtual const NOX::Abstract::GroupgetPreviousSolutionGroup () const
 Return a reference to the previous solution group.
virtual int getNumIterations () const
 Get number of iterations.
virtual const NOX::Parameter::ListgetParameterList () const
 Return a refernece to the solver parameters.
virtual double getStepSize () const
 Return the line search step size from the current iteration.

Protected Member Functions

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

Protected Attributes

NOX::Abstract::GroupsolnPtr
 Current solution.
NOX::Abstract::GroupoldSolnPtr
 Previous solution pointer.
NOX::Abstract::GroupoldSoln
 Previous solution reference.
NOX::Abstract::VectordirPtr
 Current search direction.pointer.
NOX::Abstract::Vectordir
 Current search direction.reference.
NOX::StatusTest::GenerictestPtr
 Stopping test.
NOX::Parameter::ListparamsPtr
 Input parameters.
NOX::Utils utils
 Utils.
NOX::LineSearch::Manager lineSearch
 Linesearch.
NOX::Direction::Manager direction
 Search Direction.
double step
 Current step.
int nIter
 Number of nonlinear iterations.
NOX::StatusTest::StatusType status
 Status of nonlinear solver.
NOX::Solver::PrePostOperator prePostOperator
 Pointer to a user defined NOX::Abstract::PrePostOperator 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.

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:

Output Parameters

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

"Output":

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


Constructor & Destructor Documentation

NOX::Solver::LineSearchBased::LineSearchBased NOX::Abstract::Group grp,
NOX::StatusTest::Generic tests,
NOX::Parameter::List params
 

Constructor.

See reset(NOX::Abstract::Group&, NOX::StatusTest::Generic&, NOX::Parameter::List&) for description


Member Function Documentation

bool NOX::Solver::LineSearchBased::reset NOX::Abstract::Group grp,
NOX::StatusTest::Generic tests
[virtual]
 

A soft reset of the nonlinear solver for a new problem.

This is a light-weight version of reset that takes no parameter list. Therefore, this reset only resets counters, the initial guess (contained in the grp argument) and new status tests (contained in the tests argument).

This reset allows problems to bypass the potentially time consuming parsing of the parameter lists.

Implements NOX::Solver::Generic.

bool NOX::Solver::LineSearchBased::reset NOX::Abstract::Group grp,
NOX::StatusTest::Generic tests,
NOX::Parameter::List params
[virtual]
 

Reset the nonlinear solver for a new solve.

Parameters:
grp On input, contains the intial guess. On output, contains the solution.
tests Status tests to check for convergence or failure. These tests will be modified by the solver.
params List of parameters. These parameters will be modified by the solver.
Note:
All the objects passed to reset() will be modified.

The group object will be cloned via NOX::Abstract::Group::clone(), and the vectors within will also be individually cloned via NOX::Abstract::Vector::clone().

Warning:
If the contents of grp, tests, or params are modified by the calling program after calling reset(), then the behavior of iterate() and solve() are completely undefined. To remedy this, call reset() again with the modified objects.

Implements NOX::Solver::Generic.

NOX::StatusTest::StatusType NOX::Solver::LineSearchBased::solve  )  [virtual]
 

Solve the nonlinear problem and return final status.

By "solve", we call iterate() until the NOX::StatusTest value is either NOX::StatusTest::Converged or NOX::StatusTest::Failed.

Implements NOX::Solver::Generic.


Member Data Documentation

NOX::Abstract::Vector* NOX::Solver::LineSearchBased::dirPtr [protected]
 

Current search direction.pointer.

We have both a pointer and a reference because we need to create a DERIVED object and then want to have a reference to it.

NOX::Abstract::Group* NOX::Solver::LineSearchBased::oldSolnPtr [protected]
 

Previous solution pointer.

We have both a pointer and a reference because we need to create a DERIVED object and then want to have a reference to it.


The documentation for this class was generated from the following files:
Generated on Thu Sep 18 12:40:52 2008 for NOX by doxygen 1.3.9.1