# NOX::LineSearch::Utils::Slope Class Reference

Common line search utilites for computing the slope of a function. More...

#include <NOX_LineSearch_Utils_Slope.H>

Collaboration diagram for NOX::LineSearch::Utils::Slope:

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List of all members.

## Public Member Functions

Slope (const Teuchos::RefCountPtr< NOX::GlobalData > &gd)
Default constructor.
virtual ~Slope ()
Destructor.
void reset (const Teuchos::RefCountPtr< NOX::GlobalData > &gd)
Reset method.
double computeSlope (const NOX::Abstract::Vector &dir, const NOX::Abstract::Group &grp)
Compute the inner product of the given direction and the gradient associated with the given group.
double computeSlopeWithOutJac (const NOX::Abstract::Vector &dir, const NOX::Abstract::Group &grp)
This is a variant of the computeSlope() method above optimized to work with out having to compute an explicit Jacobian.

## Detailed Description

Common line search utilites for computing the slope of a function.

This class provides routines for computing the slope of a give function. There are two methods, one that uses a Jacobian and the other that estimates the action of the Jacobian by directional derivatives.

## Member Function Documentation

 double NOX::LineSearch::Utils::Slope::computeSlope ( const NOX::Abstract::Vector & dir, const NOX::Abstract::Group & grp )
 Compute the inner product of the given direction and the gradient associated with the given group. Calculates and returns Here represents the input parameter dir and is the gradient associated with the given group.

 double NOX::LineSearch::Utils::Slope::computeSlopeWithOutJac ( const NOX::Abstract::Vector & dir, const NOX::Abstract::Group & grp )
 This is a variant of the computeSlope() method above optimized to work with out having to compute an explicit Jacobian. Calculates and returns Here represents the input parameter dir is the gradient associated with the given group (for nonlinear solves this equates to where is the Jacobian and is the original nonlinear function). We can rewrite this equation as: which allows us to use directional derivatives to estimate : This may allow for faster computations of the slope if the Jacobian is expensive to evaluate. where is a scalar perturbation calculated by: is a constant fixed at 1.0e-6.

The documentation for this class was generated from the following files:
• NOX_LineSearch_Utils_Slope.H
• NOX_LineSearch_Utils_Slope.C

Generated on Thu Sep 18 12:38:39 2008 for NOX by  1.3.9.1