basix.cell

Functions to get cell geometry information and manipulate cell types.

Functions

facet_jacobians(celltype)	Jacobians of the facets of a reference cell.
facet_normals(celltype)	Normals to the facets of a reference cell.
facet_orientations(celltype)	Orientations of the facets of a reference cell.
facet_outward_normals(celltype)	Normals to the facets of a reference cell.
facet_reference_volumes(celltype)	Reference volumes of the facets of a reference cell.
geometry(celltype)	Cell geometry.
string_to_type(cell)	Convert a string to a Basix CellType.
sub_entity_connectivity(celltype)	Numbers of entities connected to each sub-entity of the cell.
topology(celltype)	Cell topology.
volume(celltype)	Volume of a reference cell.

Classes

CellType(value)

Cell type.

basix.cell.facet_jacobians(celltype: CellType) → ndarray[Any, dtype[ScalarType]]

Jacobians of the facets of a reference cell.

Parameters:

celltype – cell type.

Returns:

Jacobians of the facets.

basix.cell.facet_normals(celltype: CellType) → ndarray[Any, dtype[ScalarType]]

Normals to the facets of a reference cell.

These normals will be oriented using the low-to-high ordering of the facet.

Parameters:

celltype – Cell type.

Returns:

Normals to the facets.

basix.cell.facet_orientations(celltype: CellType) → list[bool]

Orientations of the facets of a reference cell.

This returns a list of bools that are True if the facet normal points outwards and False otherwise.

Parameters:

celltype – Cell type.

Returns:

Facet orientations.

basix.cell.facet_outward_normals(celltype: CellType) → ndarray[Any, dtype[ScalarType]]

Normals to the facets of a reference cell.

These normals will be oriented to be pointing outwards.

Parameters:

celltype – Cell type.

Returns:

Normals to the facets.

basix.cell.facet_reference_volumes(celltype: CellType) → ndarray[Any, dtype[ScalarType]]

Reference volumes of the facets of a reference cell.

Parameters:

celltype – Cell type.

Returns:

Reference volumes.

basix.cell.string_to_type(cell: str) → CellType

Convert a string to a Basix CellType.

Parameters:

cell – Name of the cell as a string.

Returns:

The cell type.

basix.cell.sub_entity_connectivity(celltype: CellType) → list[list[list[list[int]]]]

Numbers of entities connected to each sub-entity of the cell.

Parameters:

celltype – cell type.

Returns:

Topology (vertex indices) for each dimension (0..tdim).

basix.cell.volume(celltype: CellType) → float

Volume of a reference cell.

Parameters:

celltype – Cell type.

Returns:

Volume of the reference cell.