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Reference documentation for deal.II version 8.1.0
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Classes | |
struct | PeriodicFacePair |
Functions | |
template<int dim, int spacedim> | |
double | diameter (const Triangulation< dim, spacedim > &tria) |
template<int dim, int spacedim> | |
double | volume (const Triangulation< dim, spacedim > &tria, const Mapping< dim, spacedim > &mapping=(StaticMappingQ1< dim, spacedim >::mapping)) |
template<int dim> | |
double | cell_measure (const std::vector< Point< dim > > &all_vertices, const unsigned int(&vertex_indices)[GeometryInfo< dim >::vertices_per_cell]) |
template<int dim, int spacedim> | |
void | delete_unused_vertices (std::vector< Point< spacedim > > &vertices, std::vector< CellData< dim > > &cells, SubCellData &subcelldata) |
template<int dim, int spacedim> | |
void | delete_duplicated_vertices (std::vector< Point< spacedim > > &all_vertices, std::vector< CellData< dim > > &cells, SubCellData &subcelldata, std::vector< unsigned int > &considered_vertices, const double tol=1e-12) |
template<int dim, typename Transformation , int spacedim> | |
void | transform (const Transformation &transformation, Triangulation< dim, spacedim > &triangulation) |
template<int dim, int spacedim> | |
void | shift (const Point< spacedim > &shift_vector, Triangulation< dim, spacedim > &triangulation) |
void | rotate (const double angle, Triangulation< 2 > &triangulation) |
template<int dim> | |
void | laplace_transform (const std::map< unsigned int, Point< dim > > &new_points, Triangulation< dim > &tria) |
template<int dim, int spacedim> | |
void | scale (const double scaling_factor, Triangulation< dim, spacedim > &triangulation) |
template<int dim, int spacedim> | |
void | distort_random (const double factor, Triangulation< dim, spacedim > &triangulation, const bool keep_boundary=true) |
template<int dim, template< int, int > class Container, int spacedim> | |
unsigned int | find_closest_vertex (const Container< dim, spacedim > &container, const Point< spacedim > &p) |
template<int dim, template< int, int > class Container, int spacedim> | |
std::vector< typename Container< dim, spacedim > ::active_cell_iterator > | find_cells_adjacent_to_vertex (const Container< dim, spacedim > &container, const unsigned int vertex_index) |
template<int dim, template< int, int > class Container, int spacedim> | |
Container< dim, spacedim > ::active_cell_iterator | find_active_cell_around_point (const Container< dim, spacedim > &container, const Point< spacedim > &p) |
template<int dim, template< int, int > class Container, int spacedim> | |
std::pair< typename Container < dim, spacedim > ::active_cell_iterator, Point < dim > > | find_active_cell_around_point (const Mapping< dim, spacedim > &mapping, const Container< dim, spacedim > &container, const Point< spacedim > &p) |
template<int dim, int spacedim> | |
std::pair< typename hp::DoFHandler< dim, spacedim > ::active_cell_iterator, Point < dim > > | find_active_cell_around_point (const hp::MappingCollection< dim, spacedim > &mapping, const hp::DoFHandler< dim, spacedim > &container, const Point< spacedim > &p) |
template<class Container > | |
std::vector< typename Container::active_cell_iterator > | get_active_child_cells (const typename Container::cell_iterator &cell) |
template<class Container > | |
void | get_active_neighbors (const typename Container::active_cell_iterator &cell, std::vector< typename Container::active_cell_iterator > &active_neighbors) |
template<int dim, int spacedim> | |
void | get_face_connectivity_of_cells (const Triangulation< dim, spacedim > &triangulation, SparsityPattern &connectivity) |
template<int dim, int spacedim> | |
void | partition_triangulation (const unsigned int n_partitions, Triangulation< dim, spacedim > &triangulation) |
template<int dim, int spacedim> | |
void | partition_triangulation (const unsigned int n_partitions, const SparsityPattern &cell_connection_graph, Triangulation< dim, spacedim > &triangulation) |
template<int dim, int spacedim> | |
void | get_subdomain_association (const Triangulation< dim, spacedim > &triangulation, std::vector< types::subdomain_id > &subdomain) |
template<int dim, int spacedim> | |
unsigned int | count_cells_with_subdomain_association (const Triangulation< dim, spacedim > &triangulation, const types::subdomain_id subdomain) |
template<typename Container > | |
std::list< std::pair< typename Container::cell_iterator, typename Container::cell_iterator > > | get_finest_common_cells (const Container &mesh_1, const Container &mesh_2) |
template<int dim, int spacedim> | |
bool | have_same_coarse_mesh (const Triangulation< dim, spacedim > &mesh_1, const Triangulation< dim, spacedim > &mesh_2) |
template<typename Container > | |
bool | have_same_coarse_mesh (const Container &mesh_1, const Container &mesh_2) |
template<int dim, int spacedim> | |
double | minimal_cell_diameter (const Triangulation< dim, spacedim > &triangulation) |
template<int dim, int spacedim> | |
double | maximal_cell_diameter (const Triangulation< dim, spacedim > &triangulation) |
template<int dim, int spacedim> | |
void | create_union_triangulation (const Triangulation< dim, spacedim > &triangulation_1, const Triangulation< dim, spacedim > &triangulation_2, Triangulation< dim, spacedim > &result) |
template<int dim, int spacedim> | |
Triangulation< dim, spacedim > ::DistortedCellList | fix_up_distorted_child_cells (const typename Triangulation< dim, spacedim >::DistortedCellList &distorted_cells, Triangulation< dim, spacedim > &triangulation) |
template<template< int, int > class Container, int dim, int spacedim> | |
std::map< typename Container < dim-1, spacedim > ::cell_iterator, typename Container< dim, spacedim > ::face_iterator > | extract_boundary_mesh (const Container< dim, spacedim > &volume_mesh, Container< dim-1, spacedim > &surface_mesh, const std::set< types::boundary_id > &boundary_ids=std::set< types::boundary_id >()) |
template<typename FaceIterator > | |
bool | orthogonal_equality (std::bitset< 3 > &orientation, const FaceIterator &face1, const FaceIterator &face2, const int direction, const ::Tensor< 1, FaceIterator::AccessorType::space_dimension > &offset) |
template<typename FaceIterator > | |
bool | orthogonal_equality (const FaceIterator &face1, const FaceIterator &face2, const int direction, const ::Tensor< 1, FaceIterator::AccessorType::space_dimension > &offset) |
template<typename CONTAINER > | |
void | collect_periodic_faces (const CONTAINER &container, const types::boundary_id b_id1, const types::boundary_id b_id2, const int direction, std::vector< PeriodicFacePair< typename CONTAINER::cell_iterator > > &matched_pairs, const ::Tensor< 1, CONTAINER::space_dimension > &offset=::Tensor< 1, CONTAINER::space_dimension >()) |
template<typename CONTAINER > | |
void | collect_periodic_faces (const CONTAINER &container, const types::boundary_id b_id, const int direction, std::vector< PeriodicFacePair< typename CONTAINER::cell_iterator > > &matched_pairs, const ::Tensor< 1, CONTAINER::space_dimension > &offset=::Tensor< 1, CONTAINER::space_dimension >()) |
DeclException1 (ExcInvalidNumberOfPartitions, int,<< "The number of partitions you gave is "<< arg1<< ", but must be greater than zero.") | |
DeclException1 (ExcNonExistentSubdomain, int,<< "The subdomain id "<< arg1<< " has no cells associated with it.") | |
DeclException0 (ExcTriangulationHasBeenRefined) | |
DeclException1 (ExcScalingFactorNotPositive, double,<< "The scaling factor must be positive, but is "<< arg1) | |
template<int N> | |
DeclException1 (ExcPointNotFoundInCoarseGrid, Point< N >,<< "The point <"<< arg1<< "> could not be found inside any of the "<< "coarse grid cells.") | |
template<int N> | |
DeclException1 (ExcPointNotFound, Point< N >,<< "The point <"<< arg1<< "> could not be found inside any of the "<< "subcells of a coarse grid cell.") | |
DeclException1 (ExcVertexNotUsed, unsigned int,<< "The given vertex "<< arg1<< " is not used in the given triangulation") | |
template<int dim, typename Predicate , int spacedim> | |
void | transform (const Predicate &predicate, Triangulation< dim, spacedim > &triangulation) |
template<class DH > | |
std::vector< typename DH::active_cell_iterator > | get_active_child_cells (const typename DH::cell_iterator &cell) |
template<> | |
double | cell_measure< 3 > (const std::vector< Point< 3 > > &all_vertices, const unsigned int(&vertex_indices)[GeometryInfo< 3 >::vertices_per_cell]) |
template<> | |
double | cell_measure< 2 > (const std::vector< Point< 2 > > &all_vertices, const unsigned int(&vertex_indices)[GeometryInfo< 2 >::vertices_per_cell]) |
This namespace is a collection of algorithms working on triangulations, such as shifting or rotating triangulations, but also finding a cell that contains a given point. See the descriptions of the individual functions for more information.
double GridTools::diameter | ( | const Triangulation< dim, spacedim > & | tria | ) |
Return the diameter of a triangulation. The diameter is computed using only the vertices, i.e. if the diameter should be larger than the maximal distance between boundary vertices due to a higher order mapping, then this function will not catch this.
double GridTools::volume | ( | const Triangulation< dim, spacedim > & | tria, |
const Mapping< dim, spacedim > & | mapping = (StaticMappingQ1< dim, spacedim >::mapping) |
||
) |
Compute the volume (i.e. the dim-dimensional measure) of the triangulation. We compute the measure using the integral . The integral approximated is approximated via quadrature for which we need the mapping argument.
This function also works for objects of type parallel::distributed::Triangulation, in which case the function is a collective operation.
double GridTools::cell_measure | ( | const std::vector< Point< dim > > & | all_vertices, |
const unsigned int(&) | vertex_indices[GeometryInfo< dim >::vertices_per_cell] | ||
) |
Given a list of vertices (typically obtained using Triangulation::get_vertices) as the first, and a list of vertex indices that characterize a single cell as the second argument, return the measure (area, volume) of this cell. If this is a real cell, then you can get the same result using cell->measure()
, but this function also works for cells that do not exist except that you make it up by naming its vertices from the list.
void GridTools::delete_unused_vertices | ( | std::vector< Point< spacedim > > & | vertices, |
std::vector< CellData< dim > > & | cells, | ||
SubCellData & | subcelldata | ||
) |
Remove vertices that are not referenced by any of the cells. This function is called by all GridIn::read_*
functions to eliminate vertices that are listed in the input files but are not used by the cells in the input file. While these vertices should not be in the input from the beginning, they sometimes are, most often when some cells have been removed by hand without wanting to update the vertex lists, as they might be lengthy.
This function is called by all GridIn::read_*
functions as the triangulation class requires them to be called with used vertices only. This is so, since the vertices are copied verbatim by that class, so we have to eliminate unused vertices beforehand.
Not implemented for the codimension one case.
void GridTools::delete_duplicated_vertices | ( | std::vector< Point< spacedim > > & | all_vertices, |
std::vector< CellData< dim > > & | cells, | ||
SubCellData & | subcelldata, | ||
std::vector< unsigned int > & | considered_vertices, | ||
const double | tol = 1e-12 |
||
) |
Remove vertices that are duplicated, due to the input of a structured grid, for example. If these vertices are not removed, the faces bounded by these vertices become part of the boundary, even if they are in the interior of the mesh.
This function is called by some GridIn::read_*
functions. Only the vertices with indices in considered_vertices
are tested for equality. This speeds up the algorithm, which is quadratic and thus quite slow to begin with. However, if you wish to consider all vertices, simply pass an empty vector.
Two vertices are considered equal if their difference in each coordinate direction is less than tol
.
void GridTools::transform | ( | const Transformation & | transformation, |
Triangulation< dim, spacedim > & | triangulation | ||
) |
Transform the vertices of the given triangulation by applying the function object provided as first argument to all its vertices. Since the internal consistency of a triangulation can only be guaranteed if the transformation is applied to the vertices of only one level of hierarchically refined cells, this function may only be used if all cells of the triangulation are on the same refinement level.
The transformation given as argument is used to transform each vertex. Its respective type has to offer a function-like syntax, i.e. the predicate is either an object of a type that has an operator()
, or it is a pointer to the function. In either case, argument and return value have to be of type Point<spacedim>
.
This function is used in the "Possibilities for extensions" section of step-38. It is also used in step-49.
void GridTools::shift | ( | const Point< spacedim > & | shift_vector, |
Triangulation< dim, spacedim > & | triangulation | ||
) |
Shift each vertex of the triangulation by the given shift vector. This function uses the transform() function above, so the requirements on the triangulation stated there hold for this function as well.
void GridTools::rotate | ( | const double | angle, |
Triangulation< 2 > & | triangulation | ||
) |
Rotate all vertices of the given two-dimensional triangulation in counter-clockwise sense around the origin of the coordinate system by the given angle (given in radians, rather than degrees). This function uses the transform() function above, so the requirements on the triangulation stated there hold for this function as well.
void GridTools::laplace_transform | ( | const std::map< unsigned int, Point< dim > > & | new_points, |
Triangulation< dim > & | tria | ||
) |
Transform the given triangulation smoothly to a different domain where each of the vertices at the boundary of the triangulation is mapped to the corresponding points in the new_points
map.
The way this function works is that it solves a Laplace equation for each of the dim components of a displacement field that maps the current domain into one described by new_points
. The new_points
array therefore represents the boundary values of this displacement field. The function then evaluates this displacement field at each vertex in the interior and uses it to place the mapped vertex where the displacement field locates it. Because the solution of the Laplace equation is smooth, this guarantees a smooth mapping from the old domain to the new one.
[in] | new_points | The locations where a subset of the existing vertices are to be placed. Typically, this would be a map from the vertex indices of all nodes on the boundary to their new locations, thus completely specifying the geometry of the mapped domain. However, it may also include interior points if necessary and it does not need to include all boundary vertices (although you then lose control over the exact shape of the mapped domain). |
[in,out] | tria | The Triangulation object. This object is changed in-place, i.e., the previous locations of vertices are overwritten. |
void GridTools::scale | ( | const double | scaling_factor, |
Triangulation< dim, spacedim > & | triangulation | ||
) |
Scale the entire triangulation by the given factor. To preserve the orientation of the triangulation, the factor must be positive.
This function uses the transform() function above, so the requirements on the triangulation stated there hold for this function as well.
void GridTools::distort_random | ( | const double | factor, |
Triangulation< dim, spacedim > & | triangulation, | ||
const bool | keep_boundary = true |
||
) |
Distort the given triangulation by randomly moving around all the vertices of the grid. The direction of movement of each vertex is random, while the length of the shift vector has a value of factor
times the minimal length of the active edges adjacent to this vertex. Note that factor
should obviously be well below 0.5
.
If keep_boundary
is set to true
(which is the default), then boundary vertices are not moved.
unsigned int GridTools::find_closest_vertex | ( | const Container< dim, spacedim > & | container, |
const Point< spacedim > & | p | ||
) |
Find and return the number of the used vertex in a given Container that is located closest to a given point p
. The type of the first parameter may be either Triangulation, DoFHandler, hp::DoFHandler, or MGDoFHandler.
std::vector<typename Container<dim,spacedim>::active_cell_iterator> GridTools::find_cells_adjacent_to_vertex | ( | const Container< dim, spacedim > & | container, |
const unsigned int | vertex_index | ||
) |
Find and return a vector of iterators to active cells that surround a given vertex with index vertex_index
. The type of the first parameter may be either Triangulation, DoFHandler, hp::DoFHandler, or MGDoFHandler.
For locally refined grids, the vertex itself might not be a vertex of all adjacent cells that are returned. However, it will always be either a vertex of a cell or be a hanging node located on a face or an edge of it.
Container<dim,spacedim>::active_cell_iterator GridTools::find_active_cell_around_point | ( | const Container< dim, spacedim > & | container, |
const Point< spacedim > & | p | ||
) |
Find and return an iterator to the active cell that surrounds a given point ref
. The type of the first parameter may be either Triangulation, or one of the DoF handler classes, i.e. we can find the cell around a point for iterators into each of these classes.
This is solely a wrapper function for the function of same name below. A Q1 mapping is used for the boundary, and the iterator to the cell in which the point resides is returned.
It is recommended to use the other version of this function, as it simultaneously delivers the local coordinate of the given point without additional computational cost.
std::pair<typename Container<dim,spacedim>::active_cell_iterator, Point<dim> > GridTools::find_active_cell_around_point | ( | const Mapping< dim, spacedim > & | mapping, |
const Container< dim, spacedim > & | container, | ||
const Point< spacedim > & | p | ||
) |
Find and return an iterator to the active cell that surrounds a given point p
. The type of the first parameter may be either Triangulation, DoFHandler, hp::DoFHandler, or MGDoFHandler, i.e., we can find the cell around a point for iterators into each of these classes.
The algorithm used in this function proceeds by first looking for vertex located closest to the given point, see find_closest_vertex(). Secondly, all adjacent cells to this point are found in the mesh, see find_cells_adjacent_to_vertex(). Lastly, for each of these cells, it is tested whether the point is inside. This check is performed using arbitrary boundary mappings. Still, it is possible that due to roundoff errors, the point cannot be located exactly inside the unit cell. In this case, even points at a very small distance outside the unit cell are allowed.
If a point lies on the boundary of two or more cells, then the algorithm tries to identify the cell that is of highest refinement level.
The function returns an iterator to the cell, as well as the local position of the point inside the unit cell. This local position might be located slightly outside an actual unit cell, due to numerical roundoff. Therefore, the point returned by this function should be projected onto the unit cell, using GeometryInfo::project_to_unit_cell. This is not automatically performed by the algorithm.
std::pair<typename hp::DoFHandler<dim,spacedim>::active_cell_iterator, Point<dim> > GridTools::find_active_cell_around_point | ( | const hp::MappingCollection< dim, spacedim > & | mapping, |
const hp::DoFHandler< dim, spacedim > & | container, | ||
const Point< spacedim > & | p | ||
) |
A version of the previous function where we use that mapping on a given cell that corresponds to the active finite element index of that cell. This is obviously only useful for hp problems, since the active finite element index for all other DoF handlers is always zero.
std::vector<typename Container::active_cell_iterator> GridTools::get_active_child_cells | ( | const typename Container::cell_iterator & | cell | ) |
Return a list of all descendents of the given cell that are active. For example, if the current cell is once refined but none of its children are any further refined, then the returned list will contain all its children.
If the current cell is already active, then the returned list is empty (because the cell has no children that may be active).
Since in C++ the type of the Container template argument (which can be Triangulation, DoFHandler, MGDoFHandler, or hp::DoFHandler) can not be deduced from a function call, you will have to specify it after the function name, as for example in GridTools::get_active_child_cells<DoFHandler<dim> > (cell)
.
void GridTools::get_active_neighbors | ( | const typename Container::active_cell_iterator & | cell, |
std::vector< typename Container::active_cell_iterator > & | active_neighbors | ||
) |
Extract the active cells around a given cell cell
and return them in the vector active_neighbors
.
Definition at line 1267 of file grid_tools.h.
void GridTools::get_face_connectivity_of_cells | ( | const Triangulation< dim, spacedim > & | triangulation, |
SparsityPattern & | connectivity | ||
) |
Produce a sparsity pattern in which nonzero entries indicate that two cells are connected via a common face. The diagonal entries of the sparsity pattern are also set.
The rows and columns refer to the cells as they are traversed in their natural order using cell iterators.
void GridTools::partition_triangulation | ( | const unsigned int | n_partitions, |
Triangulation< dim, spacedim > & | triangulation | ||
) |
Use the METIS partitioner to generate a partitioning of the active cells making up the entire domain. After calling this function, the subdomain ids of all active cells will have values between zero and n_partitions-1
. You can access the subdomain id of a cell by using cell->subdomain_id()
.
This function will generate an error if METIS is not installed unless n_partitions
is one. I.e., you can write a program so that it runs in the single-processor single-partition case without METIS installed, and only requires METIS when multiple partitions are required.
void GridTools::partition_triangulation | ( | const unsigned int | n_partitions, |
const SparsityPattern & | cell_connection_graph, | ||
Triangulation< dim, spacedim > & | triangulation | ||
) |
This function does the same as the previous one, i.e. it partitions a triangulation using METIS into a number of subdomains identified by the cell->subdomain_id()
flag.
The difference to the previous function is the second argument, a sparsity pattern that represents the connectivity pattern between cells.
While the function above builds it directly from the triangulation by considering which cells neighbor each other, this function can take a more refined connectivity graph. The sparsity pattern needs to be of size , where
is the number of active cells in the triangulation. If the sparsity pattern contains an entry at position
, then this means that cells
and
(in the order in which they are traversed by active cell iterators) are to be considered connected; METIS will then try to partition the domain in such a way that (i) the subdomains are of roughly equal size, and (ii) a minimal number of connections are broken.
This function is mainly useful in cases where connections between cells exist that are not present in the triangulation alone (otherwise the previous function would be the simpler one to use). Such connections may include that certain parts of the boundary of a domain are coupled through symmetric boundary conditions or integrals (e.g. friction contact between the two sides of a crack in the domain), or if a numerical scheme is used that not only connects immediate neighbors but a larger neighborhood of cells (e.g. when solving integral equations).
In addition, this function may be useful in cases where the default sparsity pattern is not entirely sufficient. This can happen because the default is to just consider face neighbors, not neighboring cells that are connected by edges or vertices. While the latter couple when using continuous finite elements, they are typically still closely connected in the neighborship graph, and METIS will not usually cut important connections in this case. However, if there are vertices in the mesh where many cells (many more than the common 4 or 6 in 2d and 3d, respectively) come together, then there will be a significant number of cells that are connected across a vertex, but several degrees removed in the connectivity graph built only using face neighbors. In a case like this, METIS may sometimes make bad decisions and you may want to build your own connectivity graph.
void GridTools::get_subdomain_association | ( | const Triangulation< dim, spacedim > & | triangulation, |
std::vector< types::subdomain_id > & | subdomain | ||
) |
For each active cell, return in the output array to which subdomain (as given by the cell->subdomain_id()
function) it belongs. The output array is supposed to have the right size already when calling this function.
This function returns the association of each cell with one subdomain. If you are looking for the association of each DoF with a subdomain, use the DoFTools::get_subdomain_association
function.
unsigned int GridTools::count_cells_with_subdomain_association | ( | const Triangulation< dim, spacedim > & | triangulation, |
const types::subdomain_id | subdomain | ||
) |
Count how many cells are uniquely associated with the given subdomain
index.
This function may return zero if there are no cells with the given subdomain
index. This can happen, for example, if you try to partition a coarse mesh into more partitions (one for each processor) than there are cells in the mesh.
This function returns the number of cells associated with one subdomain. If you are looking for the association of DoFs with this subdomain, use the DoFTools::count_dofs_with_subdomain_association
function.
std::list<std::pair<typename Container::cell_iterator, typename Container::cell_iterator> > GridTools::get_finest_common_cells | ( | const Container & | mesh_1, |
const Container & | mesh_2 | ||
) |
Given two mesh containers (i.e. objects of type Triangulation, DoFHandler, hp::DoFHandler, or MGDoFHandler) that are based on the same coarse mesh, this function figures out a set of cells that are matched between the two meshes and where at most one of the meshes is more refined on this cell. In other words, it finds the smallest cells that are common to both meshes, and that together completely cover the domain.
This function is useful, for example, in time-dependent or nonlinear application, where one has to integrate a solution defined on one mesh (e.g., the one from the previous time step or nonlinear iteration) against the shape functions of another mesh (the next time step, the next nonlinear iteration). If, for example, the new mesh is finer, then one has to obtain the solution on the coarse mesh (mesh_1) and interpolate it to the children of the corresponding cell of mesh_2. Conversely, if the new mesh is coarser, one has to express the coarse cell shape function by a linear combination of fine cell shape functions. In either case, one needs to loop over the finest cells that are common to both triangulations. This function returns a list of pairs of matching iterators to cells in the two meshes that can be used to this end.
Note that the list of these iterators is not necessarily order, and does also not necessarily coincide with the order in which cells are traversed in one, or both, of the meshes given as arguments.
bool GridTools::have_same_coarse_mesh | ( | const Triangulation< dim, spacedim > & | mesh_1, |
const Triangulation< dim, spacedim > & | mesh_2 | ||
) |
Return true if the two triangulations are based on the same coarse mesh. This is determined by checking whether they have the same number of cells on the coarsest level, and then checking that they have the same vertices.
The two meshes may have different refinement histories beyond the coarse mesh.
bool GridTools::have_same_coarse_mesh | ( | const Container & | mesh_1, |
const Container & | mesh_2 | ||
) |
The same function as above, but working on arguments of type DoFHandler, hp::DoFHandler, or MGDoFHandler. This function is provided to allow calling have_same_coarse_mesh for all types of containers representing triangulations or the classes built on triangulations.
double GridTools::minimal_cell_diameter | ( | const Triangulation< dim, spacedim > & | triangulation | ) |
Return the diamater of the smallest active cell of a triangulation. See step-24 for an example of use of this function.
double GridTools::maximal_cell_diameter | ( | const Triangulation< dim, spacedim > & | triangulation | ) |
Return the diamater of the largest active cell of a triangulation.
void GridTools::create_union_triangulation | ( | const Triangulation< dim, spacedim > & | triangulation_1, |
const Triangulation< dim, spacedim > & | triangulation_2, | ||
Triangulation< dim, spacedim > & | result | ||
) |
Given the two triangulations specified as the first two arguments, create the triangulation that contains the finest cells of both triangulation and store it in the third parameter. Previous content of result
will be deleted.
Triangulation<dim,spacedim>::DistortedCellList GridTools::fix_up_distorted_child_cells | ( | const typename Triangulation< dim, spacedim >::DistortedCellList & | distorted_cells, |
Triangulation< dim, spacedim > & | triangulation | ||
) |
Given a triangulation and a list of cells whose children have become distorted as a result of mesh refinement, try to fix these cells up by moving the center node around.
The function returns a list of cells with distorted children that couldn't be fixed up for whatever reason. The returned list is therefore a subset of the input argument.
For a definition of the concept of distorted cells, see the glossary entry. The first argument passed to the current function is typically the exception thrown by the Triangulation::execute_coarsening_and_refinement function.
std::map<typename Container<dim-1,spacedim>::cell_iterator, typename Container<dim,spacedim>::face_iterator> GridTools::extract_boundary_mesh | ( | const Container< dim, spacedim > & | volume_mesh, |
Container< dim-1, spacedim > & | surface_mesh, | ||
const std::set< types::boundary_id > & | boundary_ids = std::set< types::boundary_id >() |
||
) |
This function implements a boundary subgrid extraction. Given a <dim,spacedim>-Triangulation (the "volume mesh") the function extracts a subset of its boundary (the "surface mesh"). The boundary to be extracted is specified by a list of boundary_ids. If none is specified the whole boundary will be extracted. The function is used in step-38.
It also builds a mapping linking the cells on the surface mesh to the corresponding faces on the volume one. This mapping is the return value of the function.
Container
template type will be of kind Triangulation; in that case, the map that is returned will be between Triangulation cell iterators of the surface mesh and Triangulation face iterators of the volume mesh. However, one often needs to have this mapping between DoFHandler (or hp::DoFHandler) iterators. In that case, you can pass DoFHandler arguments as first and second parameter; the function will in that case re-build the triangulation underlying the second argument and return a map between DoFHandler iterators. However, the function will not actually distribute degrees of freedom on this newly created surface mesh.bool GridTools::orthogonal_equality | ( | std::bitset< 3 > & | orientation, |
const FaceIterator & | face1, | ||
const FaceIterator & | face2, | ||
const int | direction, | ||
const ::Tensor< 1, FaceIterator::AccessorType::space_dimension > & | offset | ||
) |
An orthogonal equality test for faces.
face1
and face2
are considered equal, if a one to one matching between its vertices can be achieved via an orthogonal equality relation: Two vertices v_1
and v_2
are considered equal, if (v_1 + offset) - v_2
is parallel to the unit vector in direction
.
If the matching was successful, the relative orientation of face1
with respect to face2
is returned in the bitset orientation
, where
In 2D face_orientation
is always true
, face_rotation
is always false
, and face_flip has the meaning of line_flip
. More precisely in 3d:
face_orientation
: true
if face1
and face2
have the same orientation. Otherwise, the vertex indices of face1
match the vertex indices of face2
in the following manner:
face_flip
: true
if the matched vertices are rotated by 180 degrees:
face_rotation
: true
if the matched vertices are rotated by 90 degrees counterclockwise:
and any combination of that... More information on the topic can be found in the glossary article.
bool GridTools::orthogonal_equality | ( | const FaceIterator & | face1, |
const FaceIterator & | face2, | ||
const int | direction, | ||
const ::Tensor< 1, FaceIterator::AccessorType::space_dimension > & | offset | ||
) |
Same function as above, but doesn't return the actual orientation
void GridTools::collect_periodic_faces | ( | const CONTAINER & | container, |
const types::boundary_id | b_id1, | ||
const types::boundary_id | b_id2, | ||
const int | direction, | ||
std::vector< PeriodicFacePair< typename CONTAINER::cell_iterator > > & | matched_pairs, | ||
const ::Tensor< 1, CONTAINER::space_dimension > & | offset = ::Tensor< 1, CONTAINER::space_dimension >() |
||
) |
This function will collect periodic face pairs on the coarsest mesh level of the given container
(a Triangulation or DoFHandler) and add them to the vector matched_pairs
leaving the original contents intact.
Define a 'first' boundary as all boundary faces having boundary_id b_id1
and a 'second' boundary consisting of all faces belonging to b_id2
.
This function tries to match all faces belonging to the first boundary with faces belonging to the second boundary with the help of orthogonal_equality().
The bitset that is returned inside of PeriodicFacePair encodes the relative orientation of the first face with respect to the second face, see the documentation of orthogonal_equality for further details.
The direction
refers to the space direction in which periodicity is enforced.
The offset
is a vector tangential to the faces that is added to the location of vertices of the 'first' boundary when attempting to match them to the corresponding vertices of the 'second' boundary. This can be used to implement conditions such as .
matched_pairs
(and existing entries will be preserved), it is possible to call this function several times with different boundary ids to generate a vector with all periodic pairs.void GridTools::collect_periodic_faces | ( | const CONTAINER & | container, |
const types::boundary_id | b_id, | ||
const int | direction, | ||
std::vector< PeriodicFacePair< typename CONTAINER::cell_iterator > > & | matched_pairs, | ||
const ::Tensor< 1, CONTAINER::space_dimension > & | offset = ::Tensor< 1, CONTAINER::space_dimension >() |
||
) |
This compatibility version of collect_periodic_face_pairs only works on grids with cells in standard orientation.
Instead of defining a 'first' and 'second' boundary with the help of two boundary_indicators this function defines a 'left' boundary as all faces with local face index 2*dimension
and boundary indicator b_id
and, similarly, a 'right' boundary consisting of all face with local face index 2*dimension+1
and boundary indicator b_id
.
This function will collect periodic face pairs on the coarsest mesh level and add them to matched_pairs
leaving the original contents intact.
GridTools::DeclException1 | ( | ExcInvalidNumberOfPartitions | , |
int | , | ||
<< "The number of partitions you gave is "<< arg1<< " | , | ||
but must be greater than zero." | |||
) |
Exception
GridTools::DeclException1 | ( | ExcNonExistentSubdomain | , |
int | , | ||
<< "The subdomain id "<< arg1<< " has no cells associated with it." | |||
) |
Exception
GridTools::DeclException0 | ( | ExcTriangulationHasBeenRefined | ) |
Exception
GridTools::DeclException1 | ( | ExcScalingFactorNotPositive | , |
double | , | ||
<< "The scaling factor must be | positive, | ||
but is"<< | arg1 | ||
) |
Exception
GridTools::DeclException1 | ( | ExcPointNotFoundInCoarseGrid | , |
Point< N > | |||
) |
Exception
GridTools::DeclException1 | ( | ExcPointNotFound | , |
Point< N > | |||
) |
Exception