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NOX::Solver::AndersonAcceleration Class Reference

Nonlinear solver based on Anderson Acceleration. More...

#include <NOX_Solver_AndersonAcceleration.H>

Inheritance diagram for NOX::Solver::AndersonAcceleration:
Inheritance graph
Collaboration diagram for NOX::Solver::AndersonAcceleration:
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Public Member Functions

 AndersonAcceleration (const Teuchos::RCP< NOX::Abstract::Group > &grp, const Teuchos::RCP< NOX::StatusTest::Generic > &tests, const Teuchos::RCP< Teuchos::ParameterList > &params)
 Constructor. More...
virtual ~AndersonAcceleration ()
virtual void reset ()
 Resets the solver for another solve. This resets the counters and status only. Uses the final solution from the last solve as the initial guess for the next solve. More...
virtual void reset (const NOX::Abstract::Vector &initialGuess)
 Resets the solver and sets a new initial guess.
virtual void reset (const NOX::Abstract::Vector &initialGuess, const Teuchos::RCP< NOX::StatusTest::Generic > &tests)
 Resets the solver, sets a new status test, and sets a new initial guess.
virtual NOX::StatusTest::StatusType step ()
 Do one nonlinear step in the iteration sequence and return status.
virtual NOX::StatusTest::StatusType solve ()
 Solve the nonlinear problem and return final status. More...
virtual const
getSolutionGroup () const
 Return a reference to the current solution group.
virtual const
getPreviousSolutionGroup () const
 Return a reference to the previous solution group.
virtual NOX::StatusTest::StatusType getStatus () const
 Returns the current status of the solver.
virtual int getNumIterations () const
 Get number of iterations.
virtual const
getList () const
 Return a reference to the solver parameters.
virtual double getStepSize () const
virtual Teuchos::RCP< const
getSolutionGroupPtr () const
 Return a RCP to the solution group.
virtual Teuchos::RCP< const
getPreviousSolutionGroupPtr () const
 Return a RCP to the previous solution group.
virtual Teuchos::RCP< const
getListPtr () const
 Return a RCP to the solver parameters.
virtual Teuchos::RCP< const
getSolverStatistics () const
 Return a RCP to the solver statistics.
- Public Member Functions inherited from NOX::Solver::Generic
 Generic ()
 Constructor (does nothing)
virtual ~Generic ()
 Destructor (does nothing)

Protected Member Functions

virtual void init ()
 Print out initialization information and calcuate the RHS.
virtual void printUpdate ()
 Prints the current iteration information.
void qrAdd (NOX::Abstract::Vector &newCol)
 Updates QR factors by addition of a column.
void qrDelete ()
 Updates QR factors by deletion of a column.
void reorthogonalize ()
 Reorthogonalized columns of Q and updates factorization.

Protected Attributes

Teuchos::RCP< NOX::GlobalDataglobalDataPtr
 Pointer to the global data object.
Teuchos::RCP< NOX::UtilsutilsPtr
< NOX::Abstract::Group
 Current solution.
< NOX::Abstract::Group
 Previous solution pointer.
< NOX::StatusTest::Generic
 Stopping test.
< Teuchos::ParameterList
 Input parameters.
< NOX::LineSearch::Generic
bool precond
 Flag for preconditioning.
bool recomputeJacobian
 Flag to recompute Jacobian each iterate. Needed if Jacobian required to apply preconditioner.
< NOX::Abstract::Vector
 Vector for temporary storage.
< NOX::Abstract::Vector
 Current preconditioned function value.
< NOX::Abstract::Vector
 Previous preconditioned function value.
int storeParam
 Maximum storage depth.
int nStore
 Current storage depth.
double mixParam
 Mixing parameter.
double stepSize
 Current step.
std::vector< Teuchos::RCP
< NOX::Abstract::Vector > > 
 "Matrix" of successive iterate differences
std::vector< Teuchos::RCP
< NOX::Abstract::Vector > > 
 Q factor the for least-squares problem.
< int, double > 
 R factor for the least-squares problem.
int nIter
 Number of nonlinear iterations.
int orthoFrequency
 Frequency for reorthogonalization of QR factors. If nonpositive, we never reorthogonalize.
NOX::StatusTest::StatusType status
 Status of nonlinear solver.
NOX::StatusTest::CheckType checkType
 Type of check to use for status tests. See NOX::StatusTest for more details.
Teuchos::RCP< NOX::Observerobserver
 Pointer to a user defined NOX::Observer object.
std::vector< double > WORK
 Scratch space for condition number estimation using LAPACK.
std::vector< int > IWORK
 Scratch space for condition number estimation using LAPACK.
bool adjustForConditionNumber
 If true, the QR matrix will be resized if the condiiton number is greater than the dropTolerance.
double dropTolerance
 Value of the condition number above which the QR matrix is resized.
int accelerationStartIteration
 The nonlinear iteration where Anderson Acceleration will start.
bool disableChecksForUnitTesting
 Disables the storage depth size check - used for unit testing corner cases only.

Detailed Description

Nonlinear solver based on Anderson Acceleration.

Solves $F(x)=0$ using Anderson Acceleration.

This method requires a mixing parameter $\beta$ and a preconditioner $M(x)$. If preconditioning is not supported, it is taken to be the identity.

For the first iteration, the solver computes $x_1 = x_0 + \beta M(x_0)F(x_0)$.

Each iteration afterward, the solver does the following.

The iterations progress until the status tests (see NOX::StatusTest) determine either failure or convergence.

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.


Alex Toth and Roger Pawlowski

Constructor & Destructor Documentation

NOX::Solver::AndersonAcceleration::AndersonAcceleration ( const Teuchos::RCP< NOX::Abstract::Group > &  grp,
const Teuchos::RCP< NOX::StatusTest::Generic > &  tests,
const Teuchos::RCP< Teuchos::ParameterList > &  params 


See reset(NOX::Abstract::Group&, NOX::StatusTest::Generic&, Teuchos::ParameterList&) for description

References NOX::DeepCopy, globalDataPtr, init(), observer, NOX::Solver::parseObserver(), Teuchos::rcp(), NOX::ShapeCopy, Teuchos::ParameterList::sublist(), utilsPtr, and NOX::Solver::validateSolverOptionsSublist().

Member Function Documentation

void NOX::Solver::AndersonAcceleration::reset ( )

Resets the solver for another solve. This resets the counters and status only. Uses the final solution from the last solve as the initial guess for the next solve.

NOTE: All NOX solvers will call reset() automatically at teh beginning of the solve() method. We add the reset() method to the solver interface for the application to call in case the application needs to reset counters and status manually before the next call to solve() is made.

Implements NOX::Solver::Generic.

References NOX::StatusTest::Unconverged.

NOX::StatusTest::StatusType NOX::Solver::AndersonAcceleration::solve ( )

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.

References Teuchos::ParameterList::set(), Teuchos::ParameterList::sublist(), and NOX::StatusTest::Unconverged.

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