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

#include <GradParsedFunction.h>

Inheritance diagram for GradParsedFunction:

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Public Member Functions
	GradParsedFunction (const InputParameters &parameters)

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

Protected Attributes
RealVectorValue	_direction
	central difference direction More...

Real	_len
	2*\|_direction\| More...

Detailed Description

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

Definition at line 27 of file GradParsedFunction.h.

Constructor & Destructor Documentation

◆ GradParsedFunction()

GradParsedFunction::GradParsedFunction ( const InputParameters & parameters )

Definition at line 27 of file GradParsedFunction.C.

   : MooseParsedFunction(parameters), _direction(getParam<RealVectorValue>("direction"))
 {
   _len = _direction.norm();
   if (_len == 0)
     mooseError("The direction in the GradParsedFunction must have positive length.");
   _direction /= 2.0; // note - so we can do central differences
 }

Member Function Documentation

◆ value()

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

virtual

Definition at line 37 of file GradParsedFunction.C.

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

Member Data Documentation

◆ _direction

RealVectorValue GradParsedFunction::_direction

protected

central difference direction

Definition at line 36 of file GradParsedFunction.h.

Referenced by GradParsedFunction(), and value().

◆ _len

Real GradParsedFunction::_len

protected

2*|_direction|

Definition at line 39 of file GradParsedFunction.h.