returns the central difference approx to the derivative (direction.nabla)^2 function viz (f(t, p + direction) - 2*f(t, p) + f(t, p - direction))/|direction|^2 This derives from MooseParsedFunction, so it already knows about a function More...

#include <Grad2ParsedFunction.h>

Inheritance diagram for Grad2ParsedFunction:

[legend]

Public Member Functions
	Grad2ParsedFunction (const InputParameters &parameters)

virtual Real	value (Real t, const Point &pt)

Protected Attributes
RealVectorValue	_direction
	central difference direction More...

Real	_len2
	\|_direction\|^2 More...

Detailed Description

returns the central difference approx to the derivative (direction.nabla)^2 function viz (f(t, p + direction) - 2*f(t, p) + f(t, p - direction))/|direction|^2 This derives from MooseParsedFunction, so it already knows about a function

Definition at line 27 of file Grad2ParsedFunction.h.

Constructor & Destructor Documentation

◆ Grad2ParsedFunction()

Grad2ParsedFunction::Grad2ParsedFunction ( const InputParameters & parameters )

Definition at line 29 of file Grad2ParsedFunction.C.

   : MooseParsedFunction(parameters), _direction(getParam<RealVectorValue>("direction"))
 {
   _len2 = _direction * _direction;
   if (_len2 == 0)
     mooseError("The direction in the Grad2ParsedFunction must have positive length.");
 }

Member Function Documentation

◆ value()

Real Grad2ParsedFunction::value	(	Real	t,
		const Point &	pt
	)

virtual

Definition at line 38 of file Grad2ParsedFunction.C.

 {
   return (_function_ptr->evaluate<Real>(t, p + _direction) -
           2 * _function_ptr->evaluate<Real>(t, p) +
           _function_ptr->evaluate<Real>(t, p - _direction)) /
          _len2;
 }

Member Data Documentation

◆ _direction

RealVectorValue Grad2ParsedFunction::_direction

protected

central difference direction

Definition at line 36 of file Grad2ParsedFunction.h.

Referenced by Grad2ParsedFunction(), and value().

◆ _len2

Real Grad2ParsedFunction::_len2

protected

|_direction|^2

Definition at line 39 of file Grad2ParsedFunction.h.