# NOX::Epetra::Interface::Required Class Reference

Supplies NOX with the set nonlinear equations. More...

`#include <NOX_Epetra_Interface_Required.H>`

Inheritance diagram for NOX::Epetra::Interface::Required:

[legend]
List of all members.

## Public Types

Residual
The exact residual (F) is being calculated.
Jac
The Jacobian matrix is being estimated.
Prec
The preconditioner matrix is being estimated.
FD_Res
The fill context is from a FD approximation (includes FDC).
MF_Res
The fill context is from a MF approximation.
MF_Jac
The fill context is from a MF computeJacobian() approximation.
User
A user defined estimation is being performed.
enum  FillType {
Residual, Jac, Prec, FD_Res,
MF_Res, MF_Jac, User
}
Type of fill that a computeF() method is used for. More...

## Public Member Functions

Required ()
Constructor.
virtual ~Required ()
Destructor.
virtual bool computeF (const Epetra_Vector &x, Epetra_Vector &F, const FillType fillFlag)=0
Compute the function, F, given the specified input vector x. Returns true if computation was successful.

## Detailed Description

Supplies NOX with the set nonlinear equations.

This is the minimum required information to solve a nonlinear problem using the NOX::Epetra objects for the linear algebra implementation. Used by NOX::Epetra::Group to provide a link to the external code for residual fills.

## Member Enumeration Documentation

Type of fill that a computeF() method is used for.

computeF() can be called for a variety of reasons:

• To evaluate the function residuals.
• To be used in an approximation to the Jacobian (finite difference or directional derivative).
• To be used in an approximation to the preconditioner.

This flag tells computeF() what the evaluation is used for. This allows the user to change the fill process to eliminate costly terms. For example, sometimes, terms in the function are very expensive and can be ignored in a Jacobian calculation. The user can query this flag and determine not to recompute such terms if the computeF() is used in a Jacobian calculation.

Enumerator:
 Residual The exact residual (F) is being calculated. Jac The Jacobian matrix is being estimated. Prec The preconditioner matrix is being estimated. FD_Res The fill context is from a FD approximation (includes FDC). MF_Res The fill context is from a MF approximation. MF_Jac The fill context is from a MF computeJacobian() approximation. User A user defined estimation is being performed.

The documentation for this class was generated from the following file:
• NOX_Epetra_Interface_Required.H

Generated on Tue Oct 20 12:46:35 2009 for NOX by  1.4.7