Mesh.h¶

Note

The documentation on this page was automatically extracted from the DOLFIN C++ code and may need to be edited or expanded.

class Mesh¶

Parent class(es)

Variable

Hierarchical

A Mesh consists of a set of connected and numbered mesh entities.

Both the representation and the interface are dimension-independent, but a concrete interface is also provided for standard named mesh entities:

Entity	Dimension	Codimension
Vertex	0
Edge	1
Face	2
Facet		1
Cell		0

When working with mesh iterators, all entities and connectivity are precomputed automatically the first time an iterator is created over any given topological dimension or connectivity.

Note that for efficiency, only entities of dimension zero (vertices) and entities of the maximal dimension (cells) exist when creating a Mesh. Other entities must be explicitly created by calling init(). For example, all edges in a mesh may be created by a call to mesh.init(1). Similarly, connectivities such as all edges connected to a given vertex must also be explicitly created (in this case by a call to mesh.init(0, 1)).

Mesh()¶: Create empty mesh

Mesh(MPI_Comm comm)¶: Create empty mesh

Mesh(const Mesh &mesh)¶

Copy constructor.

Arguments

mesh (Mesh): Object to be copied.

explicit Mesh(std::string filename)¶

Create mesh from data file.

Arguments

filename (std::string): Name of file to load.

Mesh(MPI_Comm comm, std::string filename)¶

Create mesh from data file.

Arguments

comm (MPI_Comm): The MPI communicator
filename (std::string): Name of file to load.

Mesh(MPI_Comm comm, LocalMeshData &local_mesh_data)¶

Create a distributed mesh from local (per process) data.

Arguments

comm (MPI_Comm): MPI communicator for the mesh.
local_mesh_data (LocalMeshData): Data from which to build the mesh.

const Mesh &operator=(const Mesh &mesh)¶

Assignment operator

Arguments

mesh (Mesh): Another Mesh object.

std::size_t num_vertices() const¶

Get number of vertices in mesh.

Returns

std::size_t: Number of vertices.

Example

Note

No example code available for this function.

std::size_t num_edges() const¶

Get number of edges in mesh.

Returns

std::size_t: Number of edges.

Example

Note

No example code available for this function.

std::size_t num_faces() const¶

Get number of faces in mesh.

Returns

std::size_t: Number of faces.

Example

Note

No example code available for this function.

std::size_t num_facets() const¶

Get number of facets in mesh.

Returns

std::size_t: Number of facets.

Example

Note

No example code available for this function.

std::size_t num_cells() const¶

Get number of cells in mesh.

Returns

std::size_t: Number of cells.

Example

Note

No example code available for this function.

std::size_t num_entities(std::size_t d) const¶

Get number of entities of given topological dimension.

Arguments

d (std::size_t): Topological dimension.

Returns

std::size_t: Number of entities of topological dimension d.

Example

Note

No example code available for this function.

std::vector<double> &coordinates()¶

Get vertex coordinates.

Returns

std::vector<double>&: Coordinates of all vertices.

Example

Note

No example code available for this function.

const std::vector<double> &coordinates() const¶: Return coordinates of all vertices (const version).

const std::vector<unsigned int> &cells() const¶

Get cell connectivity.

Returns

std::vector<std::size_t>: Connectivity for all cells.

Example

Note

No example code available for this function.

std::size_t size(std::size_t dim) const¶

Get number of local entities of given topological dimension.

Arguments

dim (std::size_t): Topological dimension.

Returns

std::size_t: Number of local entities of topological dimension d.

Example

Note

No example code available for this function.

std::size_t size_global(std::size_t dim) const¶

Get global number of entities of given topological dimension.

Arguments

dim (std::size_t): Topological dimension.

Returns

std::size_t: Global number of entities of topological dimension d.

Example

Note

No example code available for this function.

MeshTopology &topology()¶

Get mesh topology.

Returns

MeshTopology: The topology object associated with the mesh.

const MeshTopology &topology() const¶: Get mesh topology (const version).

MeshGeometry &geometry()¶

Get mesh geometry.

Returns

MeshGeometry: The geometry object associated with the mesh.

const MeshGeometry &geometry() const¶: Get mesh geometry (const version).

MeshDomains &domains()¶

Get mesh (sub)domains.

Returns

MeshDomains: The (sub)domains associated with the mesh.

const MeshDomains &domains() const¶: Get mesh (sub)domains.

std::shared_ptr<BoundingBoxTree> bounding_box_tree() const¶: Get bounding box tree for mesh. The bounding box tree is initialized and built upon the first call to this function. The bounding box tree can be used to compute collisions between the mesh and other objects. It is the responsibility of the caller to use (and possibly rebuild) the tree. It is stored as a (mutable) member of the mesh to enable sharing of the bounding box tree data structure.

MeshData &data()¶

Get mesh data.

Returns

MeshData: The mesh data object associated with the mesh.

const MeshData &data() const¶: Get mesh data (const version).

CellType &type()¶

Get mesh cell type.

Returns

CellType: The cell type object associated with the mesh.

const CellType &type() const¶: Get mesh cell type (const version).

std::size_t init(std::size_t dim) const¶

Compute entities of given topological dimension.

Arguments

dim (std::size_t): Topological dimension.

Returns

std::size_t: Number of created entities.

void init(std::size_t d0, std::size_t d1) const¶

Compute connectivity between given pair of dimensions.

Arguments

d0 (std::size_t): Topological dimension.
d1 (std::size_t): Topological dimension.

void init() const¶: Compute all entities and connectivity.

void init_global(std::size_t dim) const¶: Compute global indices for entity dimension dim

void clean()¶: Clean out all auxiliary topology data. This clears all topological data, except the connectivity between cells and vertices.

void order()¶: Order all mesh entities.

See also

UFC documentation (put link here!)

bool ordered() const¶

Check if mesh is ordered according to the UFC numbering convention.

Returns

bool: The return values is true iff the mesh is ordered.

Mesh renumber_by_color() const¶: Renumber mesh entities by coloring. This function is currently restricted to renumbering by cell coloring. The cells (cell-vertex connectivity) and the coordinates of the mesh are renumbered to improve the locality within each color. It is assumed that the mesh has already been colored and that only cell-vertex connectivity exists as part of the mesh.

void translate(const Point &point)¶

Translate mesh according to a given vector.

Arguments

point (Point): The vector defining the translation.

void rotate(double angle, std::size_t axis = 2)¶

Rotate mesh around a coordinate axis through center of mass of all mesh vertices

Arguments

angle (double): The number of degrees (0-360) of rotation.
axis (std::size_t): The coordinate axis around which to rotate the mesh.

void rotate(double angle, std::size_t axis, const Point &point)¶

Rotate mesh around a coordinate axis through a given point

Arguments

angle (double): The number of degrees (0-360) of rotation.
axis (std::size_t): The coordinate axis around which to rotate the mesh.
point (Point): The point around which to rotate the mesh.

void smooth(std::size_t num_iterations = 1)¶

Smooth internal vertices of mesh by local averaging.

Arguments

num_iterations (std::size_t): Number of iterations to perform smoothing, default value is 1.

void smooth_boundary(std::size_t num_iterations = 1, bool harmonic_smoothing = true)¶

Smooth boundary vertices of mesh by local averaging.

Arguments

num_iterations (std::size_t): Number of iterations to perform smoothing, default value is 1.
harmonic_smoothing (bool): Flag to turn on harmonics smoothing, default value is true.

void snap_boundary(const SubDomain &sub_domain, bool harmonic_smoothing = true)¶

Snap boundary vertices of mesh to match given sub domain.

Arguments

sub_domain (SubDomain): A SubDomain object.
harmonic_smoothing (bool): Flag to turn on harmonics smoothing, default value is true.

const std::vector<std::size_t> &color(std::string coloring_type) const¶

Color the cells of the mesh such that no two neighboring cells share the same color. A colored mesh keeps a CellFunction<std::size_t> named “cell colors” as mesh data which holds the colors of the mesh.

Arguments

coloring_type (std::string): Coloring type, specifying what relation makes two cells neighbors, can be one of “vertex”, “edge” or “facet”.

Returns

std::vector<std::size_t>: The colors as a mesh function over the cells of the mesh.

const std::vector<std::size_t> &color(std::vector<std::size_t> coloring_type) const¶

Color the cells of the mesh such that no two neighboring cells share the same color. A colored mesh keeps a CellFunction<std::size_t> named “cell colors” as mesh data which holds the colors of the mesh.

Arguments

coloring_type (std::vector<std::size_t>): Coloring type given as list of topological dimensions, specifying what relation makes two mesh entities neighbors.

Returns

std::vector<std::size_t>: The colors as a mesh function over entities of the mesh.

double hmin() const¶

Compute minimum cell size in mesh, measured greatest distance between any two vertices of a cell.

Returns

double: The minimum cell size. The size is computed using Cell::h()

Example

Note

No example code available for this function.

double hmax() const¶

Compute maximum cell size in mesh, measured greatest distance between any two vertices of a cell.

Returns

double: The maximum cell size. The size is computed using Cell::h()

Example

Note

No example code available for this function.

double rmin() const¶

Compute minimum cell inradius.

Returns

double: The minimum of cells’ inscribed sphere radii

Example

Note

No example code available for this function.

double rmax() const¶

Compute maximum cell inradius.

Returns

double: The maximum of cells’ inscribed sphere radii

Example

Note

No example code available for this function.

std::size_t hash() const¶

Compute hash of mesh, currently based on the has of the mesh geometry and mesh topology.

Returns

std::size_t: A tree-hashed value of the coordinates over all MPI processes

std::string str(bool verbose) const¶

Informal string representation.

Arguments

verbose (bool): Flag to turn on additional output.

Returns

std::string: An informal representation of the mesh.

Example

Note

No example code available for this function.

const std::vector<int> &cell_orientations() const¶

Return cell_orientations (const version)

Returns

std::vector<int>: Map from cell index to orientation of cell. Is empty if cell orientations have not been computed.

void init_cell_orientations(const Expression &global_normal)¶

Compute and initialize cell_orientations relative to a given global outward direction/normal/orientation. Only defined if mesh is orientable.

Arguments

global_normal (Expression): A global normal direction to the mesh

MPI_Comm mpi_comm() const¶: Mesh MPI communicator