libMesh::FunctionBase< Output > Class Template Reference

Base class for functors that can be evaluated at a point and (optionally) time. More...

#include <dirichlet_boundaries.h>

Inheritance diagram for libMesh::FunctionBase< Output >:

Public Member Functions
	FunctionBase (FunctionBase &&)=default
	The 5 special functions can be defaulted for this class. More...
	FunctionBase (const FunctionBase &)=default
FunctionBase &	operator= (const FunctionBase &)=default
FunctionBase &	operator= (FunctionBase &&)=default
virtual	~FunctionBase ()=default
virtual void	init ()
	The actual initialization process. More...
virtual void	clear ()
	Clears the function. More...
virtual std::unique_ptr< FunctionBase< Output > >	clone () const =0
virtual Output	operator() (const Point &p, const Real time=0.)=0
void	operator() (const Point &p, DenseVector< Output > &output)
	Evaluation function for time-independent vector-valued functions. More...
virtual void	operator() (const Point &p, const Real time, DenseVector< Output > &output)=0
	Evaluation function for time-dependent vector-valued functions. More...
virtual Output	component (unsigned int i, const Point &p, Real time=0.)
bool	initialized () const
void	set_is_time_dependent (bool is_time_dependent)
	Function to set whether this is a time-dependent function or not. More...
bool	is_time_dependent () const

Protected Member Functions
	FunctionBase (const FunctionBase *master=nullptr)
	Constructor. More...

Protected Attributes
const FunctionBase *	_master
	Const pointer to our master, initialized to nullptr. More...
bool	_initialized
	When init() was called so that everything is ready for calls to operator() (...), then this bool is true. More...
bool	_is_time_dependent
	Cache whether or not this function is actually time-dependent. More...

Detailed Description

template<typename Output = Number>
class libMesh::FunctionBase< Output >

Base class for functors that can be evaluated at a point and (optionally) time.

Instances of FunctionBase represent functions (in the mathematical sense) of time and space, \( f(\mathbf{x},t) = \mbox{\texttt{v}} \), where v may be either a Number or a DenseVector<Number>. Children of this base class implement different styles of data retrieval for these functions. Use the constructors of the derived classes for creating new objects. The required input of each derived class thwarts the effective use of the commonly used build() member. But afterward the virtual members allow the convenient and libMesh-common usage through a FunctionBase *.

Note

For functor objects for vector-valued variables, it is assumed each component is indexed contiguously; i.e. if u_var is index 3, then libMesh expects the x-component of u_var is index 3, the y-component is index 4, and the z-component is index 5.

For 2-D elements in 3 spatial dimensions, libMesh is expecting 2 components (i.e. mesh_dimension() number of components).

Author

Daniel Dreyer

Date

2003

Definition at line 44 of file dirichlet_boundaries.h.

Constructor & Destructor Documentation

FunctionBase() [1/3]

template<typename Output >

libMesh::FunctionBase< Output >::FunctionBase ( const FunctionBase< Output > *  master = nullptr )

inlineexplicitprotected

Constructor.

Optionally takes a master.

Definition at line 194 of file function_base.h.

                                                               :
  _master             (master),
  _initialized        (false),
  _is_time_dependent  (true) // Assume we are time-dependent until the user says otherwise
{
}

FunctionBase() [2/3]

template<typename Output = Number>

libMesh::FunctionBase< Output >::FunctionBase ( FunctionBase< Output > &&  )

default

The 5 special functions can be defaulted for this class.

FunctionBase() [3/3]

template<typename Output = Number>

libMesh::FunctionBase< Output >::FunctionBase ( const FunctionBase< Output > &  )

default

~FunctionBase()

template<typename Output = Number>

virtual libMesh::FunctionBase< Output >::~FunctionBase ( )

virtualdefault

Member Function Documentation

clear()

template<typename Output = Number>

virtual void libMesh::FunctionBase< Output >::clear ( )

inlinevirtual

Clears the function.

Reimplemented in libMesh::MeshFunction, libMesh::AnalyticFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, libMesh::MeshlessInterpolationFunction, libMesh::MeshlessInterpolationFunction, and ExampleOneFunction.

Definition at line 91 of file function_base.h.

{}

clone()

template<typename Output = Number>

virtual std::unique_ptr<FunctionBase<Output> > libMesh::FunctionBase< Output >::clone ( ) const

pure virtual

Returns

A new copy of the function.

The new copy should be as "deep" as necessary to allow independent destruction and simultaneous evaluations of the copies in different threads.

Implemented in libMesh::MeshTools::Generation::Private::GaussLobattoRedistributionFunction, libMesh::CompositeFunction< Output >, libMesh::MeshFunction, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, libMesh::AnalyticFunction< Output >, libMesh::WrappedFunction< Output >, libMesh::ConstFunction< Output >, libMesh::ZeroFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, TripleFunction, SolutionGradient, SolutionGradient, SolutionGradient, libMesh::MeshlessInterpolationFunction, libMesh::MeshlessInterpolationFunction, BdyFunction, SolutionFunction, BdyFunction, SolutionFunction, SolutionFunction, BdyFunction, and ExampleOneFunction.

Referenced by libMesh::ExactErrorEstimator::attach_exact_deriv(), libMesh::ExactSolution::attach_exact_deriv(), libMesh::ExactErrorEstimator::attach_exact_hessian(), libMesh::ExactSolution::attach_exact_hessian(), libMesh::ExactErrorEstimator::attach_exact_value(), libMesh::ExactSolution::attach_exact_value(), libMesh::CompositeFunction< Output >::attach_subfunction(), libMesh::DirichletBoundary::DirichletBoundary(), and libMesh::MeshTools::Modification::redistribute().

component()

template<typename Output >

Output libMesh::FunctionBase< Output >::component ( unsigned int  i, const Point &  p, Real  time = 0.  )

inlinevirtual

Returns

The vector component i at coordinate p and time time.

Note

Subclasses aren't required to override this, since the default implementation is based on the full vector evaluation, which is often correct.

Subclasses are recommended to override this, since the default implementation is based on a vector evaluation, which is usually unnecessarily inefficient.

Reimplemented in TripleFunction, libMesh::WrappedFunction< Output >, libMesh::CompositeFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, SolutionGradient, SolutionGradient, SolutionGradient, SolutionFunction, SolutionFunction, and SolutionFunction.

Definition at line 227 of file function_base.h.

{
  DenseVector<Output> outvec(i+1);
  (*this)(p, time, outvec);
  return outvec(i);
}

init()

template<typename Output = Number>

virtual void libMesh::FunctionBase< Output >::init ( )

inlinevirtual

The actual initialization process.

Reimplemented in libMesh::MeshFunction, libMesh::AnalyticFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, libMesh::MeshlessInterpolationFunction, libMesh::MeshlessInterpolationFunction, and ExampleOneFunction.

Definition at line 86 of file function_base.h.

{}

initialized()

template<typename Output >

bool libMesh::FunctionBase< Output >::initialized ( ) const

inline

Returns

true when this object is properly initialized and ready for use, false otherwise.

Definition at line 205 of file function_base.h.

{
  return (this->_initialized);
}

is_time_dependent()

template<typename Output >

bool libMesh::FunctionBase< Output >::is_time_dependent ( ) const

inline

Returns

true when the function this object represents is actually time-dependent, false otherwise.

Definition at line 219 of file function_base.h.

{
  return (this->_is_time_dependent);
}

Referenced by libMesh::CompositeFunction< Output >::attach_subfunction(), CompositeFunctionTest::testTimeDependence(), and ParsedFunctionTest::testTimeDependence().

operator()() [1/3]

template<typename Output = Number>

virtual void libMesh::FunctionBase< Output >::operator() ( const Point &  p, const Real  time, DenseVector< Output > &  output  )

pure virtual

Evaluation function for time-dependent vector-valued functions.

Sets output values in the passed-in output DenseVector.

Pure virtual, so you have to override it.

Implemented in libMesh::MeshTools::Generation::Private::GaussLobattoRedistributionFunction, SolutionGradient, SolutionGradient, SolutionGradient, libMesh::ParsedFunction< T >, libMesh::CompositeFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::AnalyticFunction< Output >, libMesh::WrappedFunction< Output >, libMesh::MeshFunction, libMesh::MeshlessInterpolationFunction, libMesh::MeshlessInterpolationFunction, libMesh::ParsedFunction< T >, libMesh::ConstFunction< Output >, and libMesh::ParsedFunction< Output, OutputGradient >.

operator()() [2/3]

template<typename Output = Number>

virtual Output libMesh::FunctionBase< Output >::operator() ( const Point &  p, const Real  time = 0.  )

pure virtual

Returns

The scalar function value at coordinate p and time time, which defaults to zero.

Pure virtual, so you have to override it.

Implemented in libMesh::MeshlessInterpolationFunction, libMesh::MeshFunction, libMesh::AnalyticFunction< Output >, libMesh::WrappedFunction< Output >, libMesh::MeshlessInterpolationFunction, libMesh::CompositeFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, TripleFunction, libMesh::ConstFunction< Output >, libMesh::ParsedFunction< Output, OutputGradient >, libMesh::ParsedFunction< T >, SolutionGradient, SolutionGradient, SolutionGradient, BdyFunction, BdyFunction, SolutionFunction, SolutionFunction, SolutionFunction, BdyFunction, libMesh::MeshTools::Generation::Private::GaussLobattoRedistributionFunction, and ExampleOneFunction.

operator()() [3/3]

template<typename Output>

void libMesh::FunctionBase< Output >::operator() ( const Point &  p, DenseVector< Output > &  output  )

inline

Evaluation function for time-independent vector-valued functions.

Sets output values in the passed-in output DenseVector.

Definition at line 240 of file function_base.h.

{
  // Call the time-dependent function with t=0.
  this->operator()(p, 0., output);
}

operator=() [1/2]

template<typename Output = Number>

FunctionBase& libMesh::FunctionBase< Output >::operator= ( const FunctionBase< Output > &  )

default

operator=() [2/2]

template<typename Output = Number>

FunctionBase& libMesh::FunctionBase< Output >::operator= ( FunctionBase< Output > &&  )

default

set_is_time_dependent()

template<typename Output >

void libMesh::FunctionBase< Output >::set_is_time_dependent ( bool  is_time_dependent )

inline

Function to set whether this is a time-dependent function or not.

This is intended to be only used by subclasses who cannot natively determine time-dependence. In such a case, this function should be used immediately following construction.

Definition at line 212 of file function_base.h.

{
  this->_is_time_dependent = is_time_dependent;
}

Member Data Documentation

_initialized

template<typename Output = Number>

bool libMesh::FunctionBase< Output >::_initialized

protected

When init() was called so that everything is ready for calls to operator() (...), then this bool is true.

Definition at line 179 of file function_base.h.

Referenced by libMesh::AnalyticFunction< Output >::AnalyticFunction(), libMesh::ConstFunction< Output >::ConstFunction(), and libMesh::WrappedFunction< Output >::WrappedFunction().

_is_time_dependent

template<typename Output = Number>

bool libMesh::FunctionBase< Output >::_is_time_dependent

protected

Cache whether or not this function is actually time-dependent.

Definition at line 184 of file function_base.h.

Referenced by libMesh::CompositeFunction< Output >::attach_subfunction(), and libMesh::ConstFunction< Output >::ConstFunction().

_master

template<typename Output = Number>

const FunctionBase* libMesh::FunctionBase< Output >::_master

protected

Const pointer to our master, initialized to nullptr.

There may be cases where multiple functions are required, but to save memory, one master handles some centralized data.

Definition at line 173 of file function_base.h.

---

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

• include/base/dirichlet_boundaries.h
• include/numerics/function_base.h