lf::mesh::utils::MeshFunctionGlobal< F > Class Template Reference

MeshFunction wrapper for a simple function of physical coordinates. More...

#include <lf/uscalfe/uscalfe.h>

Public Member Functions
	MeshFunctionGlobal (const MeshFunctionGlobal &)=default
	MeshFunctionGlobal (MeshFunctionGlobal &&) noexcept=default
MeshFunctionGlobal &	operator= (const MeshFunctionGlobal &)=delete
MeshFunctionGlobal &	operator= (MeshFunctionGlobal &&)=delete
	MeshFunctionGlobal (F f)
std::vector< F_return_type >	operator() (const mesh::Entity &e, const Eigen::MatrixXd &local) const
	MeshFunction compliant evaluation operator.
virtual	~MeshFunctionGlobal ()=default

Private Types
using	F_return_type

Private Attributes
F	f_

Detailed Description

template<class F>
class lf::mesh::utils::MeshFunctionGlobal< F >

MeshFunction wrapper for a simple function of physical coordinates.

Template Parameters

F	a functor type, offering an evaluation operator that acccepts a single coordinate vector.

MeshFunctionGlobal essentially wraps a function object which represents a function defined on the mesh that depends only on the global coordinates. An example is e.g. the function \( \vec{x} \mapsto \norm{x}^2 \).

Requirements for F

F is a function object that should overload the call operator as follows:

auto operator()(const Eigen::Vector2d& x) const

which should return the value of the mesh function at the global coordinates x. The return type of the call operator can in principle be anything, but usually it is one of:

• double for a scalar valued mesh function
• std::complex<double> for complex valued mesh function
• Eigen::Vector2d for a tensor valued mesh function.

For instance, a MeshFunctionGlobal object may be instantiated with a lambda function.

Note

For DimGlobal==3, the call operator should of course accept a Eigen::Vector3d.

Use case

  // Define a tensor field through a lambda function
  auto alpha = [](Eigen::Vector2d x) -> Eigen::Matrix<double, 2, 2> {
    return (Eigen::Matrix<double, 2, 2>() << (3.0 + x[1]), x[0], x[0],
            (2.0 + x[0]))
        .finished();
  };
  // Wrap the tensor field into a MeshFunction
  lf::mesh::utils::MeshFunctionGlobal mf_alpha{alpha};
  // evaluate the tensor field at the nodes of the mesh
  const Eigen::Matrix<double, 0, 1> dummy;
  for (const lf::mesh::Entity* node : mesh.Entities(2)) {
    const std::vector<Eigen::Matrix<double, 2, 2>> a{mf_alpha(*node, dummy)};
    std::cout << a[0] << std::endl;
  }

Definition at line 55 of file mesh_function_global.h.

Member Typedef Documentation

F_return_type

template<class F>

using lf::mesh::utils::MeshFunctionGlobal< F >::F_return_type

private

Initial value:

 
      decltype(std::declval<F>()(std::declval<Eigen::Vector2d>()))

Definition at line 56 of file mesh_function_global.h.

Constructor & Destructor Documentation

MeshFunctionGlobal() [1/3]

template<class F>

lf::mesh::utils::MeshFunctionGlobal< F >::MeshFunctionGlobal ( const MeshFunctionGlobal< F > & )

default

References MeshFunctionGlobal().

Referenced by MeshFunctionGlobal(), MeshFunctionGlobal(), MeshFunctionGlobal(), operator=(), and operator=().

MeshFunctionGlobal() [2/3]

template<class F>

lf::mesh::utils::MeshFunctionGlobal< F >::MeshFunctionGlobal ( MeshFunctionGlobal< F > && )

defaultnoexcept

References MeshFunctionGlobal().

MeshFunctionGlobal() [3/3]

template<class F>

lf::mesh::utils::MeshFunctionGlobal< F >::MeshFunctionGlobal ( F f )

inlineexplicit

Definition at line 72 of file mesh_function_global.h.

References f_, and MeshFunctionGlobal().

~MeshFunctionGlobal()

template<class F>

virtual lf::mesh::utils::MeshFunctionGlobal< F >::~MeshFunctionGlobal ( )

virtualdefault

Member Function Documentation

operator()()

template<class F>

std::vector< F_return_type > lf::mesh::utils::MeshFunctionGlobal< F >::operator() ( const mesh::Entity & e, const Eigen::MatrixXd & local ) const

inline

MeshFunction compliant evaluation operator.

Definition at line 77 of file mesh_function_global.h.

References lf::base::RefEl::Dimension(), f_, lf::mesh::Entity::Geometry(), lf::geometry::Geometry::Global(), and lf::mesh::Entity::RefEl().

operator=() [1/2]

template<class F>

MeshFunctionGlobal & lf::mesh::utils::MeshFunctionGlobal< F >::operator= ( const MeshFunctionGlobal< F > & )

delete

References MeshFunctionGlobal().

operator=() [2/2]

template<class F>

MeshFunctionGlobal & lf::mesh::utils::MeshFunctionGlobal< F >::operator= ( MeshFunctionGlobal< F > && )

delete

References MeshFunctionGlobal().

Member Data Documentation

f_

template<class F>

F lf::mesh::utils::MeshFunctionGlobal< F >::f_

private

Definition at line 93 of file mesh_function_global.h.

Referenced by MeshFunctionGlobal(), and operator()().

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

• /home/runner/work/lehrfempp/lehrfempp/lib/lf/mesh/utils/mesh_function_global.h