dolfinx::io::cells Namespace Reference

Functions for the re-ordering of input mesh topology to the DOLFINx ordering, and transpose orderings for file output. More...

Functions
std::vector< std::uint8_t >	perm_vtk (mesh::CellType type, int num_nodes)
	Permutation array to map from VTK to DOLFINx node ordering. More...
std::vector< std::uint8_t >	perm_gmsh (mesh::CellType type, int num_nodes)
	Permutation array to map from Gmsh to DOLFINx node ordering. More...
std::vector< std::uint8_t >	transpose (const std::vector< std::uint8_t > &map)
	Compute the transpose of a re-ordering map. More...
std::vector< std::int64_t >	apply_permutation (const std::span< const std::int64_t > &cells, std::array< std::size_t, 2 > shape, const std::span< const std::uint8_t > &p)
	Permute cell topology by applying a permutation array for each cell. More...
std::int8_t	get_vtk_cell_type (mesh::CellType cell, int dim)
	Get VTK cell identifier. More...

Detailed Description

Functions for the re-ordering of input mesh topology to the DOLFINx ordering, and transpose orderings for file output.

Function Documentation

apply_permutation()

std::vector< std::int64_t > apply_permutation	(	const std::span< const std::int64_t > &	cells,
		std::array< std::size_t, 2 >	shape,
		const std::span< const std::uint8_t > &	p
	)

Permute cell topology by applying a permutation array for each cell.

Parameters

[in]	cells	Array of cell topologies, with each row representing a cell (row-major storage)
[in]	shape	The shape of the cells array
[in]	p	The permutation array that maps a_p[i] = a[p[i]], where a_p is the permuted array

Returns

Permuted cell topology, where for a cell v_new[i] = v_old[map[i]]. The storage is row-major and the shape is the same as cells.

get_vtk_cell_type()

std::int8_t get_vtk_cell_type	(	mesh::CellType	cell,
		int	dim
	)

Get VTK cell identifier.

Parameters

[in]	cell	The cell type
[in]	dim	The topological dimension of the cell

Returns

The VTK cell identifier

perm_gmsh()

std::vector< std::uint8_t > perm_gmsh	(	mesh::CellType	type,
		int	num_nodes
	)

Permutation array to map from Gmsh to DOLFINx node ordering.

Parameters

[in]	type	The cell shape
[in]	num_nodes

Returns

Permutation array for permuting from Gmsh ordering to DOLFINx ordering, i.e. a_dolfin[i] = a_gmsh[p[i]] @details Ifp = [0, 2, 1, 3]anda = [10, 3, 4, 7], thena_p =[a[p[0]], a[p[1]], a[p[2]], a[p[3]]] = [10, 4, 3, 7]`

perm_vtk()

std::vector< std::uint8_t > perm_vtk	(	mesh::CellType	type,
		int	num_nodes
	)

Permutation array to map from VTK to DOLFINx node ordering.

Parameters

[in]	type	The cell shape
[in]	num_nodes	The number of cell 'nodes'

Returns

Permutation array for permuting from VTK ordering to DOLFINx ordering, i.e. a_dolfin[i] = a_vtk[p[i]] @details Ifp = [0, 2, 1, 3]anda = [10, 3, 4, 7], thena_p =[a[p[0]], a[p[1]], a[p[2]], a[p[3]]] = [10, 4, 3, 7]`

transpose()

std::vector< std::uint8_t > transpose

(

const std::vector< std::uint8_t > &

map

)

Compute the transpose of a re-ordering map.

Parameters

[in]

map

A re-ordering map

Returns

Transpose of the map. E.g., is map = {1, 2, 3, 0}, the transpose will be {3 , 0, 1, 2 }.