Reference documentation for deal.II version 9.4.0
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Public Types | Public Member Functions | Static Public Member Functions | Public Attributes | Static Public Attributes | Private Attributes | List of all members
AutoDerivativeFunction< dim > Class Template Reference

#include <deal.II/base/auto_derivative_function.h>

Inheritance diagram for AutoDerivativeFunction< dim >:
[legend]

Public Types

enum  DifferenceFormula { Euler , UpwindEuler , FourthOrder }
 
using time_type = typename FunctionTime< typename numbers::NumberTraits< RangeNumberType >::real_type >::time_type
 

Public Member Functions

 AutoDerivativeFunction (const double h, const unsigned int n_components=1, const double initial_time=0.0)
 
virtual ~AutoDerivativeFunction () override=default
 
void set_formula (const DifferenceFormula formula=Euler)
 
void set_h (const double h)
 
virtual Tensor< 1, dim > gradient (const Point< dim > &p, const unsigned int component=0) const override
 
virtual void vector_gradient (const Point< dim > &p, std::vector< Tensor< 1, dim > > &gradients) const override
 
virtual void gradient_list (const std::vector< Point< dim > > &points, std::vector< Tensor< 1, dim > > &gradients, const unsigned int component=0) const override
 
virtual void vector_gradient_list (const std::vector< Point< dim > > &points, std::vector< std::vector< Tensor< 1, dim > > > &gradients) const override
 
virtual RangeNumberType value (const Point< dim > &p, const unsigned int component=0) const
 
virtual void vector_value (const Point< dim > &p, Vector< RangeNumberType > &values) const
 
virtual void value_list (const std::vector< Point< dim > > &points, std::vector< RangeNumberType > &values, const unsigned int component=0) const
 
virtual void vector_value_list (const std::vector< Point< dim > > &points, std::vector< Vector< RangeNumberType > > &values) const
 
virtual void vector_values (const std::vector< Point< dim > > &points, std::vector< std::vector< RangeNumberType > > &values) const
 
virtual void vector_gradient (const Point< dim > &p, std::vector< Tensor< 1, dim, RangeNumberType > > &gradients) const
 
virtual void gradient_list (const std::vector< Point< dim > > &points, std::vector< Tensor< 1, dim, RangeNumberType > > &gradients, const unsigned int component=0) const
 
virtual void vector_gradients (const std::vector< Point< dim > > &points, std::vector< std::vector< Tensor< 1, dim, RangeNumberType > > > &gradients) const
 
virtual void vector_gradient_list (const std::vector< Point< dim > > &points, std::vector< std::vector< Tensor< 1, dim, RangeNumberType > > > &gradients) const
 
virtual RangeNumberType laplacian (const Point< dim > &p, const unsigned int component=0) const
 
virtual void vector_laplacian (const Point< dim > &p, Vector< RangeNumberType > &values) const
 
virtual void laplacian_list (const std::vector< Point< dim > > &points, std::vector< RangeNumberType > &values, const unsigned int component=0) const
 
virtual void vector_laplacian_list (const std::vector< Point< dim > > &points, std::vector< Vector< RangeNumberType > > &values) const
 
virtual SymmetricTensor< 2, dim, RangeNumberType > hessian (const Point< dim > &p, const unsigned int component=0) const
 
virtual void vector_hessian (const Point< dim > &p, std::vector< SymmetricTensor< 2, dim, RangeNumberType > > &values) const
 
virtual void hessian_list (const std::vector< Point< dim > > &points, std::vector< SymmetricTensor< 2, dim, RangeNumberType > > &values, const unsigned int component=0) const
 
virtual void vector_hessian_list (const std::vector< Point< dim > > &points, std::vector< std::vector< SymmetricTensor< 2, dim, RangeNumberType > > > &values) const
 
virtual std::size_t memory_consumption () const
 
numbers::NumberTraits< double >::real_type get_time () const
 
virtual void set_time (const numbers::NumberTraits< double >::real_type new_time)
 
virtual void advance_time (const numbers::NumberTraits< double >::real_type delta_t)
 

Static Public Member Functions

static DifferenceFormula get_formula_of_order (const unsigned int ord)
 

Public Attributes

const unsigned int n_components
 

Static Public Attributes

static constexpr unsigned int dimension = dim
 

Private Attributes

double h
 
std::vector< Tensor< 1, dim > > ht
 
DifferenceFormula formula
 
numbers::NumberTraits< double >::real_type time
 

Subscriptor functionality

Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.

std::atomic< unsigned intcounter
 
std::map< std::string, unsigned intcounter_map
 
std::vector< std::atomic< bool > * > validity_pointers
 
const std::type_info * object_info
 
void subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
 
void unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
 
unsigned int n_subscriptions () const
 
template<typename StreamType >
void list_subscribers (StreamType &stream) const
 
void list_subscribers () const
 
template<class Archive >
void serialize (Archive &ar, const unsigned int version)
 
static ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (std::string arg1, std::string arg2)
 
using map_value_type = decltype(counter_map)::value_type
 
using map_iterator = decltype(counter_map)::iterator
 
static std::mutex mutex
 
void check_no_subscribers () const noexcept
 

Detailed Description

template<int dim>
class AutoDerivativeFunction< dim >

This class automatically computes the gradient of a function by employing numerical difference quotients. This only, if the user function does not provide the gradient function himself.

The following example of an user defined function overloads and implements only the value() function but not the gradient() function. If the gradient() function is invoked then the gradient function implemented by the AutoDerivativeFunction is called, where the latter function employs numerical difference quotients.

class UserFunction: public AutoDerivativeFunction
{
// access to one component at one point
double value (const Point<dim> &p,
const unsigned int component = 0) const override
{
// Implementation ....
};
};
UserFunction user_function;
// gradient by employing difference quotients.
Tensor<1,dim> grad=user_function.gradient(some_point);
virtual RangeNumberType value(const Point< dim > &p, const unsigned int component=0) const
Definition: point.h:111

If the user overloads and implements also the gradient function, then, of course, the users gradient function is called.

Note, that the usage of the value() and gradient() functions explained above, also applies to the value_list() and gradient_list() functions as well as to the vector valued versions of these functions, see e.g. vector_value(), vector_gradient(), vector_value_list() and vector_gradient_list().

The gradient() and gradient_list() functions make use of the Function::value() function. The vector_gradient() and vector_gradient_list() make use of the Function::vector_value() function. Make sure that the user defined function implements the value() function and the vector_value() function, respectively.

Furthermore note, that an object of this class does not represent the derivative of a function, like FunctionDerivative, that gives a directional derivative by calling the value() function. In fact, this class (the AutoDerivativeFunction class) can substitute the Function class as base class for user defined classes. This class implements the gradient() functions for automatic computation of numerical difference quotients and serves as intermediate class between the base Function class and the user defined function class.

Definition at line 82 of file auto_derivative_function.h.

Member Typedef Documentation

◆ time_type

template<int dim, typename RangeNumberType = double>
using Function< dim, RangeNumberType >::time_type = typename FunctionTime< typename numbers::NumberTraits<RangeNumberType>::real_type>::time_type
inherited

The scalar-valued real type used for representing time.

Definition at line 169 of file function.h.

Member Enumeration Documentation

◆ DifferenceFormula

Names of difference formulas.

Enumerator
Euler 

The symmetric Euler formula of second order:

\[ u'(t) \approx \frac{u(t+h) - u(t-h)}{2h}. \]

UpwindEuler 

The upwind Euler formula of first order:

\[ u'(t) \approx \frac{u(t) - u(t-h)}{h}. \]

FourthOrder 

The fourth order scheme

\[ u'(t) \approx \frac{u(t-2h) - 8u(t-h) + 8u(t+h) - u(t+2h)}{12h}. \]

Definition at line 88 of file auto_derivative_function.h.

Constructor & Destructor Documentation

◆ AutoDerivativeFunction()

template<int dim>
AutoDerivativeFunction< dim >::AutoDerivativeFunction ( const double  h,
const unsigned int  n_components = 1,
const double  initial_time = 0.0 
)

Constructor. Takes the difference step size h. It's within the user's responsibility to choose an appropriate value here. h should be chosen taking into account the absolute value as well as the amount of local variation of the function. Setting h=1e-6 might be a good choice for functions with an absolute value of about 1, that furthermore does not vary to much.

h can be changed later using the set_h() function.

Sets DifferenceFormula formula to the default Euler formula of the set_formula() function. Change this preset formula by calling the set_formula() function.

Definition at line 26 of file auto_derivative_function.cc.

◆ ~AutoDerivativeFunction()

template<int dim>
virtual AutoDerivativeFunction< dim >::~AutoDerivativeFunction ( )
overridevirtualdefault

Virtual destructor; absolutely necessary in this case.

Member Function Documentation

◆ set_formula()

template<int dim>
void AutoDerivativeFunction< dim >::set_formula ( const DifferenceFormula  formula = Euler)

Choose the difference formula. See the enum DifferenceFormula for available choices.

Definition at line 43 of file auto_derivative_function.cc.

◆ set_h()

template<int dim>
void AutoDerivativeFunction< dim >::set_h ( const double  h)

Takes the difference step size h. It's within the user's responsibility to choose an appropriate value here. h should be chosen taking into account the absolute value of as well as the amount of local variation of the function. Setting h=1e-6 might be a good choice for functions with an absolute value of about 1, that furthermore does not vary to much.

Definition at line 65 of file auto_derivative_function.cc.

◆ gradient()

template<int dim>
Tensor< 1, dim > AutoDerivativeFunction< dim >::gradient ( const Point< dim > &  p,
const unsigned int  component = 0 
) const
overridevirtual

Return the gradient of the specified component of the function at the given point.

Compute numerical difference quotients using the preset DifferenceFormula.

Reimplemented from Function< dim, RangeNumberType >.

Definition at line 75 of file auto_derivative_function.cc.

◆ vector_gradient() [1/2]

template<int dim>
void AutoDerivativeFunction< dim >::vector_gradient ( const Point< dim > &  p,
std::vector< Tensor< 1, dim > > &  gradients 
) const
overridevirtual

Return the gradient of all components of the function at the given point.

Compute numerical difference quotients using the preset DifferenceFormula.

Definition at line 127 of file auto_derivative_function.cc.

◆ gradient_list() [1/2]

template<int dim>
void AutoDerivativeFunction< dim >::gradient_list ( const std::vector< Point< dim > > &  points,
std::vector< Tensor< 1, dim > > &  gradients,
const unsigned int  component = 0 
) const
overridevirtual

Set gradients to the gradients of the specified component of the function at the points. It is assumed that gradients already has the right size, i.e. the same size as the points array.

Compute numerical difference quotients using the preset DifferenceFormula.

Definition at line 204 of file auto_derivative_function.cc.

◆ vector_gradient_list() [1/2]

template<int dim>
void AutoDerivativeFunction< dim >::vector_gradient_list ( const std::vector< Point< dim > > &  points,
std::vector< std::vector< Tensor< 1, dim > > > &  gradients 
) const
overridevirtual

Set gradients to the gradients of the function at the points, for all components. It is assumed that gradients already has the right size, i.e. the same size as the points array.

The outer loop over gradients is over the points in the list, the inner loop over the different components of the function.

Compute numerical difference quotients using the preset DifferenceFormula.

Definition at line 268 of file auto_derivative_function.cc.

◆ get_formula_of_order()

template<int dim>
AutoDerivativeFunction< dim >::DifferenceFormula AutoDerivativeFunction< dim >::get_formula_of_order ( const unsigned int  ord)
static

Return a DifferenceFormula of the order ord at minimum.

Definition at line 336 of file auto_derivative_function.cc.

◆ value()

template<int dim, typename RangeNumberType = double>
virtual RangeNumberType Function< dim, RangeNumberType >::value ( const Point< dim > &  p,
const unsigned int  component = 0 
) const
virtualinherited

Return the value of the function at the given point. Unless there is only one component (i.e. the function is scalar), you should state the component you want to have evaluated; it defaults to zero, i.e. the first component.

Reimplemented in Functions::CosineGradFunction< dim >, Functions::ConstantFunction< dim, RangeNumberType >, Functions::ConstantFunction< dim, double >, Functions::IdentityFunction< dim, RangeNumberType >, ScalarFunctionFromFunctionObject< dim, RangeNumberType >, VectorFunctionFromScalarFunctionObject< dim, RangeNumberType >, FunctionFromFunctionObjects< dim, RangeNumberType >, VectorFunctionFromTensorFunction< dim, RangeNumberType >, FunctionDerivative< dim >, Functions::SquareFunction< dim >, Functions::Q1WedgeFunction< dim >, Functions::PillowFunction< dim >, Functions::CosineFunction< dim >, Functions::ExpFunction< dim >, Functions::SlitSingularityFunction< dim >, Functions::JumpFunction< dim >, Functions::FourierCosineFunction< dim >, Functions::FourierSineFunction< dim >, Functions::FourierSineSum< dim >, Functions::FourierCosineSum< dim >, Functions::CutOffFunctionTensorProduct< dim >, Functions::CutOffFunctionLinfty< dim >, Functions::CutOffFunctionW1< dim >, Functions::CutOffFunctionC1< dim >, Functions::CutOffFunctionCinfty< dim >, Functions::Monomial< dim, Number >, Functions::InterpolatedTensorProductGridData< dim >, Functions::InterpolatedUniformGridData< dim >, Functions::Polynomial< dim >, FunctionParser< dim >, Functions::IncrementalFunction< dim, RangeNumberType >, Functions::ParsedFunction< dim >, Functions::SymbolicFunction< dim, RangeNumberType >, Functions::FEFieldFunction< dim, VectorType, spacedim >, Functions::CoordinateRestriction< dim >, Functions::CSpline< dim >, Functions::SignedDistance::Sphere< dim >, Functions::SignedDistance::Plane< dim >, Functions::SignedDistance::Ellipsoid< dim >, Functions::Spherical< dim >, NonMatching::internal::DiscreteQuadratureGeneratorImplementation::RefSpaceFEFieldFunction< dim, VectorType >, Functions::FlowFunction< dim >, Functions::FlowFunction< 2 >, and Functions::Bessel1< dim >.

◆ vector_value()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_value ( const Point< dim > &  p,
Vector< RangeNumberType > &  values 
) const
virtualinherited

Return all components of a vector-valued function at a given point.

values shall have the right size beforehand, i.e. n_components.

The default implementation will call value() for each component.

Reimplemented in Functions::ConstantFunction< dim, double >, and Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ value_list()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::value_list ( const std::vector< Point< dim > > &  points,
std::vector< RangeNumberType > &  values,
const unsigned int  component = 0 
) const
virtualinherited

Set values to the point values of the specified component of the function at the points. It is assumed that values already has the right size, i.e. the same size as the points array.

By default, this function repeatedly calls value() for each point separately, to fill the output array.

Reimplemented in Functions::ConstantFunction< dim, double >, and Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ vector_value_list()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_value_list ( const std::vector< Point< dim > > &  points,
std::vector< Vector< RangeNumberType > > &  values 
) const
virtualinherited

Set values to the point values of the function at the points. It is assumed that values already has the right size, i.e. the same size as the points array, and that all elements be vectors with the same number of components as this function has.

By default, this function repeatedly calls vector_value() for each point separately, to fill the output array.

Reimplemented in Functions::ConstantFunction< dim, double >, and Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ vector_values()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_values ( const std::vector< Point< dim > > &  points,
std::vector< std::vector< RangeNumberType > > &  values 
) const
virtualinherited

For each component of the function, fill a vector of values, one for each point.

The default implementation of this function in Function calls value_list() for each component. In order to improve performance, this can be reimplemented in derived classes to speed up performance.

◆ vector_gradient() [2/2]

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_gradient ( const Point< dim > &  p,
std::vector< Tensor< 1, dim, RangeNumberType > > &  gradients 
) const
virtualinherited

Return the gradient of all components of the function at the given point.

Reimplemented in Functions::ConstantFunction< dim, double >, and Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ gradient_list() [2/2]

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::gradient_list ( const std::vector< Point< dim > > &  points,
std::vector< Tensor< 1, dim, RangeNumberType > > &  gradients,
const unsigned int  component = 0 
) const
virtualinherited

Set gradients to the gradients of the specified component of the function at the points. It is assumed that gradients already has the right size, i.e. the same size as the points array.

Reimplemented in Functions::FEFieldFunction< dim, VectorType, spacedim >, and Functions::ConstantFunction< dim, double >.

◆ vector_gradients()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_gradients ( const std::vector< Point< dim > > &  points,
std::vector< std::vector< Tensor< 1, dim, RangeNumberType > > > &  gradients 
) const
virtualinherited

For each component of the function, fill a vector of gradient values, one for each point.

The default implementation of this function in Function calls value_list() for each component. In order to improve performance, this can be reimplemented in derived classes to speed up performance.

◆ vector_gradient_list() [2/2]

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_gradient_list ( const std::vector< Point< dim > > &  points,
std::vector< std::vector< Tensor< 1, dim, RangeNumberType > > > &  gradients 
) const
virtualinherited

Set gradients to the gradients of the function at the points, for all components. It is assumed that gradients already has the right size, i.e. the same size as the points array.

The outer loop over gradients is over the points in the list, the inner loop over the different components of the function.

Reimplemented in Functions::FEFieldFunction< dim, VectorType, spacedim >, and Functions::ConstantFunction< dim, double >.

◆ laplacian()

template<int dim, typename RangeNumberType = double>
virtual RangeNumberType Function< dim, RangeNumberType >::laplacian ( const Point< dim > &  p,
const unsigned int  component = 0 
) const
virtualinherited

◆ vector_laplacian()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_laplacian ( const Point< dim > &  p,
Vector< RangeNumberType > &  values 
) const
virtualinherited

Compute the Laplacian of all components at point p and store them in values.

Reimplemented in Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ laplacian_list()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::laplacian_list ( const std::vector< Point< dim > > &  points,
std::vector< RangeNumberType > &  values,
const unsigned int  component = 0 
) const
virtualinherited

Compute the Laplacian of one component at a set of points.

Reimplemented in Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ vector_laplacian_list()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_laplacian_list ( const std::vector< Point< dim > > &  points,
std::vector< Vector< RangeNumberType > > &  values 
) const
virtualinherited

Compute the Laplacians of all components at a set of points.

Reimplemented in Functions::FEFieldFunction< dim, VectorType, spacedim >.

◆ hessian()

template<int dim, typename RangeNumberType = double>
virtual SymmetricTensor< 2, dim, RangeNumberType > Function< dim, RangeNumberType >::hessian ( const Point< dim > &  p,
const unsigned int  component = 0 
) const
virtualinherited

◆ vector_hessian()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_hessian ( const Point< dim > &  p,
std::vector< SymmetricTensor< 2, dim, RangeNumberType > > &  values 
) const
virtualinherited

Compute the Hessian of all components at point p and store them in values.

◆ hessian_list()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::hessian_list ( const std::vector< Point< dim > > &  points,
std::vector< SymmetricTensor< 2, dim, RangeNumberType > > &  values,
const unsigned int  component = 0 
) const
virtualinherited

Compute the Hessian of one component at a set of points.

◆ vector_hessian_list()

template<int dim, typename RangeNumberType = double>
virtual void Function< dim, RangeNumberType >::vector_hessian_list ( const std::vector< Point< dim > > &  points,
std::vector< std::vector< SymmetricTensor< 2, dim, RangeNumberType > > > &  values 
) const
virtualinherited

Compute the Hessians of all components at a set of points.

◆ memory_consumption()

template<int dim, typename RangeNumberType = double>
virtual std::size_t Function< dim, RangeNumberType >::memory_consumption ( ) const
virtualinherited

◆ get_time()

numbers::NumberTraits< double >::real_type FunctionTime< numbers::NumberTraits< double >::real_type >::get_time ( ) const
inherited

Return the value of the time variable.

◆ set_time()

virtual void FunctionTime< numbers::NumberTraits< double >::real_type >::set_time ( const numbers::NumberTraits< double >::real_type  new_time)
virtualinherited

Set the time to new_time, overwriting the old value.

◆ advance_time()

virtual void FunctionTime< numbers::NumberTraits< double >::real_type >::advance_time ( const numbers::NumberTraits< double >::real_type  delta_t)
virtualinherited

Advance the time by the given time step delta_t.

Member Data Documentation

◆ h

template<int dim>
double AutoDerivativeFunction< dim >::h
private

Step size of the difference formula. Set by the set_h() function.

Definition at line 223 of file auto_derivative_function.h.

◆ ht

template<int dim>
std::vector<Tensor<1, dim> > AutoDerivativeFunction< dim >::ht
private

Includes the unit vectors scaled by h.

Definition at line 228 of file auto_derivative_function.h.

◆ formula

template<int dim>
DifferenceFormula AutoDerivativeFunction< dim >::formula
private

Difference formula. Set by the set_formula() function.

Definition at line 233 of file auto_derivative_function.h.

◆ dimension

template<int dim, typename RangeNumberType = double>
constexpr unsigned int Function< dim, RangeNumberType >::dimension = dim
staticconstexprinherited

Export the value of the template parameter as a static member constant. Sometimes useful for some expression template programming.

Definition at line 159 of file function.h.

◆ n_components

template<int dim, typename RangeNumberType = double>
const unsigned int Function< dim, RangeNumberType >::n_components
inherited

Number of vector components.

Definition at line 164 of file function.h.

◆ time

numbers::NumberTraits< double >::real_type FunctionTime< numbers::NumberTraits< double >::real_type >::time
privateinherited

Store the present time.

Definition at line 113 of file function_time.h.


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