Reference documentation for deal.II version Git 6fa7894 20171212 13:14:59 +0100

Functions  
template<typename MeshIteratorType >  
constexpr std::size_t  n_default_points_per_cell () 
template<typename MeshIteratorType >  
Quadrature< MeshIteratorType::AccessorType::space_dimension >  get_default_quadrature (const MeshIteratorType &iterator, const bool with_laplace=false) 
template<typename MeshIteratorType >  
std::pair< std::array< Point< MeshIteratorType::AccessorType::space_dimension >, n_default_points_per_cell< MeshIteratorType >)>, std::array< double, n_default_points_per_cell< MeshIteratorType >)> >  get_default_points_and_weights (const MeshIteratorType &iterator, const bool with_laplace=false) 
We collect here some helper functions used in the Manifold<dim,spacedim> classes.

inline 
A constexpr
helper function that returns the number of default points for the structure type pointed to by the given MeshIteratorType
. See the documentation of Manifolds::get_default_points_and_weights() for more information.
Definition at line 50 of file manifold.h.
Quadrature<MeshIteratorType::AccessorType::space_dimension> Manifolds::get_default_quadrature  (  const MeshIteratorType &  iterator, 
const bool  with_laplace = false 

) 
Given a general mesh iterator, construct a quadrature object that contains the following points:
The quadrature weights for these points are either chosen identically and equal to one over the number of quadrature points (if with_laplace
is false
), or in a way that gives points closer to the cell center (measured on the reference cell) a higher weight. These weights correspond to solving a Laplace equation and evaluating the solution at the quadrature points (if with_laplace
is true
).
The function is primarily used to construct the input argument for the Manifold::get_new_point() function, which computes a new point on a manifold based on a weighted average of "surrounding" points represented by the quadrature points and weights stored in a Quadrature object. This function creates such an object based on the points that "surround" a cell, face, or edge, and weights are chosen in a way appropriate for computing the new "midpoint" of the object pointed to. An example of where this is necessary is for mesh refinement, where (using the 2d situation as an example) we need to first create new edge midpoints, and then a new cellpoint.
[in]  iterator  A mesh iterator that points to either a line, quad, or hex. 
[in]  with_laplace  Whether or not to compute the quadrature weights by solving a Laplace equation, as discussed above. 
MeshIteratorType  An iterator type that corresponds to either Triangulation::cell_iterator (or variants such as Triangulation::active_cell_iterator or DoFHandler::cell_iterator) or that is the result of statements such as cell>face(f) or cell>line(l) . 
std::pair<std::array<Point<MeshIteratorType::AccessorType::space_dimension>, n_default_points_per_cell<MeshIteratorType>)>, std::array<double, n_default_points_per_cell<MeshIteratorType>)> > Manifolds::get_default_points_and_weights  (  const MeshIteratorType &  iterator, 
const bool  with_laplace = false 

) 
Given a general mesh iterator, construct arrays of quadrature points and weights that contain the following points:
The quadrature weights for these points are either chosen identically and equal to one over the number of quadrature points (if with_laplace
is false
), or in a way that gives points closer to the cell center (measured on the reference cell) a higher weight. These weights correspond to solving a Laplace equation and evaluating the solution at the quadrature points (if with_laplace
is true
).
The function is primarily used to construct the input argument for the Manifold::get_new_point() function, which computes a new point on a manifold based on a weighted average of "surrounding" points represented by the quadrature points and weights stored in the returned pair of vectors. This function creates such an object based on the points that "surround" a cell, face, or edge, and weights are chosen in a way appropriate for computing the new "midpoint" of the object pointed to. An example of where this is necessary is for mesh refinement, where (using the 2d situation as an example) we need to first create new edge midpoints, and then a new cellpoint.
[in]  iterator  A mesh iterator that points to either a line, quad, or hex. 
[in]  with_laplace  Whether or not to compute the quadrature weights by solving a Laplace equation, as discussed above. 
MeshIteratorType  An iterator type that corresponds to either Triangulation::cell_iterator (or variants such as Triangulation::active_cell_iterator or DoFHandler::cell_iterator) or that is the result of statements such as cell>face(f) or cell>line(l) . 