NOX::Petsc::Group Class Reference

Concrete implementation of NOX::Abstract::Group for Petsc. More...

#include <NOX_Petsc_Group.H>

Inheritance diagram for NOX::Petsc::Group:

[legend]Collaboration diagram for NOX::Petsc::Group:[legend]List of all members.


Public Member Functions
	Group (Interface &i, Vec &x, Mat &J)
	Constructor.
	Group (const Group &source, CopyType type=DeepCopy)
	Copy constructor. If type is DeepCopy, takes ownership of valid shared Jacobian.
virtual	~Group ()
	Destructor.
virtual Abstract::Group &	operator= (const NOX::Abstract::Group &source)
	Copies the source group into this group.
virtual Abstract::Group &	operator= (const Group &source)
	See above.
virtual Abstract::Group *	clone (CopyType type=DeepCopy) const
"Compute" functions.
virtual void	setX (const Vector &y)
virtual void	setX (const Abstract::Vector &y)
	See above.
virtual void	computeX (const Group &grp, const Vector &d, double step)
virtual void	computeX (const Abstract::Group &grp, const Abstract::Vector &d, double step)
	See above.
virtual Abstract::Group::ReturnType	computeF ()
	Compute and store F(x).
virtual Abstract::Group::ReturnType	computeJacobian ()
	Compute and store Jacobian.
virtual Abstract::Group::ReturnType	computeGradient ()
	Compute and store gradient.
virtual Abstract::Group::ReturnType	computeNewton (Parameter::List &params)
Jacobian operations.
Operations using the Jacobian matrix. These may not be defined in matrix-free scenarios.
virtual Abstract::Group::ReturnType	applyJacobian (const Vector &input, Vector &result) const
virtual Abstract::Group::ReturnType	applyJacobian (const Abstract::Vector &input, Abstract::Vector &result) const
	See above.
virtual Abstract::Group::ReturnType	applyJacobianTranspose (const Vector &input, Vector &result) const
virtual Abstract::Group::ReturnType	applyJacobianTranspose (const Abstract::Vector &input, Abstract::Vector &result) const
	See above.
virtual Abstract::Group::ReturnType	applyRightPreconditioning (const Vector &input, Vector &result) const
	Preconditions a vector using one of the available methods in Petsc.
virtual Abstract::Group::ReturnType	applyRightPreconditioning (Parameter::List &, const Abstract::Vector &input, Abstract::Vector &result) const
	See above.
"Is" functions
Checks to see if various objects have been computed. Returns true if the corresponding "compute" function has been called since the last update to the solution vector (via instantiation or computeX).
virtual bool	isF () const
	Return true if F is valid.
virtual bool	isJacobian () const
	Return true if the Jacobian is valid.
virtual bool	isGradient () const
	Return true if the gradient is valid.
virtual bool	isNewton () const
	Return true if the Newton direction is valid.
virtual bool	isPreconditioner () const
"Get" functions
Note that these function do not check whether or not the vectors are valid. Must use the "Is" functions for that purpose.
virtual const Abstract::Vector &	getX () const
	Return solution vector.
virtual const Abstract::Vector &	getF () const
	Return F(x).
virtual double	getNormF () const
	Return 2-norm of F(x).
virtual const Abstract::Vector &	getGradient () const
	Return gradient.
virtual const Abstract::Vector &	getNewton () const
	Return Newton direction.
Protected Member Functions
virtual void	resetIsValid ()
	resets the isValid flags to false
Protected Attributes
double	normRHS
	Norm of RHS.
SharedJacobian *	sharedJacobianPtr
	Pointer to shared Jacobian matrix.
SharedJacobian &	sharedJacobian
	Reference to shared Jacobian matrix.
string	jacType
	Specification of Jacobian Type.
Interface &	userInterface
	Reference to the user supplied interface functions.
Vectors
Vector	xVector
	Solution vector.
Vector	RHSVector
	Right-hand-side vector (function evaluation).
Vector	gradVector
	Gradient vector (steepest descent vector).
Vector	NewtonVector
	Newton direction vector.
IsValid flags
True if the current solution is up-to-date with respect to the currect xVector.
bool	isValidRHS
bool	isValidJacobian
bool	isValidGrad
bool	isValidNewton
bool	isValidPreconditioner

Detailed Description

Concrete implementation of NOX::Abstract::Group for Petsc.

Member Function Documentation

Abstract::Group::ReturnType Group::applyRightPreconditioning ( const Vector & input,

Vector & result

) const [virtual]

Preconditions a vector using one of the available methods in Petsc.
Currently, the preconditioning method corresponds to whatever is available in the user's Petsc installation and is specified in the local .petscrc file. For example, a direct solve can be accomplished by specifying -pc_type lu (serial only), whereas diagonal scaling can be achieved via -pc_type jacobi.

Abstract::Group::ReturnType Group::computeF ( ) [virtual]

Compute and store F(x).

Note:
It's generally useful to also compute and store the 2-norm of F(x) at this point for later access by the getNormF() function.

Returns:

NOX::Abstract::Group::Failed - If the computation fails in any way

NOX::Abstract::Group::Ok - Otherwise

Implements NOX::Abstract::Group.

Abstract::Group::ReturnType Group::computeGradient ( ) [virtual]

Compute and store gradient.
We can pose the nonlinear equation problem $F(x) = 0$ as an optimization problem as follows:
$\min f(x) \equiv \frac{1}{2} \|F(x)\|_2^2.$

In that case, the gradient (of $f$ ) is defined as
$g \equiv J^T F.$

Returns:

NOX::Abstract::Group::NotDefined - Returned by default implementation in NOX::Abstract::Group

NOX::Abstract::Group::BadDependency - If either $F$ or $J$ has not been computed

NOX::Abstract::Group::Failed - If the computation fails in any other way

NOX::Abstract::Group::Ok - Otherwise

Reimplemented from NOX::Abstract::Group.

Abstract::Group::ReturnType Group::computeJacobian ( ) [virtual]

Compute and store Jacobian.
Recall that
$F(x) = \left[ \begin{array}{c} F_1(x) \\ F_2(x) \\ \vdots \\ F_n(x) \\ \end{array} \right].$

The Jacobian is denoted by $J$ and defined by
$J_{ij} = \frac{\partial F_i}{\partial x_j} (x).$

Note:
If this is a shared object, this group should taken ownership of the Jacobian before it computes it.

Returns:

NOX::Abstract::Group::NotDefined - Returned by default implementation in NOX::Abstract::Group

NOX::Abstract::Group::Failed - If the computation fails in any other way

NOX::Abstract::Group::Ok - Otherwise

Reimplemented from NOX::Abstract::Group.

double Group::getNormF ( ) const [virtual]

Return 2-norm of F(x).
In other words,
$\sqrt{\sum_{i=1}^n F_i^2}$

Implements NOX::Abstract::Group.

bool Group::isGradient ( ) const [virtual]

Return true if the gradient is valid.

Note:
Default implementation in NOX::Abstract::Group returns false.

Reimplemented from NOX::Abstract::Group.

bool Group::isJacobian ( ) const [virtual]

Return true if the Jacobian is valid.

Note:
Default implementation in NOX::Abstract::Group returns false.

Reimplemented from NOX::Abstract::Group.

bool Group::isNewton ( ) const [virtual]

Return true if the Newton direction is valid.

Note:
Default implementation in NOX::Abstract::Group returns false.

Reimplemented from NOX::Abstract::Group.

Abstract::Group & Group::operator= ( const NOX::Abstract::Group & source ) [virtual]

Copies the source group into this group.

Note:
Any shared data owned by the source should have its ownership transfered to this group. This may result in a secret modification to the source object.

Implements NOX::Abstract::Group.

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

NOX_Petsc_Group.H
NOX_Petsc_Group.C

Generated on Thu Sep 18 12:42:29 2008 for NOX by

1.3.9.1

NOX::Petsc::Group Class Reference

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation