Basix Python interface documentation

basix

Basix is a finite element definition and tabulation runtime library.

The core of the library is written in C++, but the majority of Basix’s functionality can be used via this Python interface.

class basix.CellType(self: basix._basixcpp.CellType, value: int) None

Bases: pybind11_builtins.pybind11_object

Members:

point

interval

triangle

tetrahedron

quadrilateral

hexahedron

prism

pyramid

hexahedron = <CellType.hexahedron: 5>
interval = <CellType.interval: 1>
property name
point = <CellType.point: 0>
prism = <CellType.prism: 6>
pyramid = <CellType.pyramid: 7>
quadrilateral = <CellType.quadrilateral: 4>
tetrahedron = <CellType.tetrahedron: 3>
triangle = <CellType.triangle: 2>
property value
class basix.ElementFamily(self: basix._basixcpp.ElementFamily, value: int) None

Bases: pybind11_builtins.pybind11_object

Members:

custom

P

DP

BDM

RT

N1E

N2E

Regge

Bubble

Serendipity

DPC

CR

BDM = <ElementFamily.BDM: 4>
Bubble = <ElementFamily.Bubble: 10>
CR = <ElementFamily.CR: 6>
DP = <ElementFamily.DP: 8>
DPC = <ElementFamily.DPC: 9>
N1E = <ElementFamily.N1E: 3>
N2E = <ElementFamily.N2E: 5>
P = <ElementFamily.P: 1>
RT = <ElementFamily.RT: 2>
Regge = <ElementFamily.Regge: 7>
Serendipity = <ElementFamily.Serendipity: 11>
custom = <ElementFamily.custom: 0>
property name
property value
class basix.LatticeType(self: basix._basixcpp.LatticeType, value: int) None

Bases: pybind11_builtins.pybind11_object

Members:

equispaced

gll

equispaced = <LatticeType.equispaced: 0>
gll = <LatticeType.gll: 1>
property name
property value
basix.compute_jacobi_deriv(arg0: float, arg1: int, arg2: int, arg3: numpy.ndarray[numpy.float64]) numpy.ndarray[numpy.float64]

Compute jacobi polynomial and derivatives at points

basix.create_element(*args, **kwargs)

Overloaded function.

  1. create_element(arg0: basix._basixcpp.ElementFamily, arg1: basix._basixcpp.CellType, arg2: int) -> basix._basixcpp.FiniteElement

Create a FiniteElement of a given family, celltype and degree

  1. create_element(arg0: basix._basixcpp.ElementFamily, arg1: basix._basixcpp.CellType, arg2: int, arg3: basix._basixcpp.LatticeType) -> basix._basixcpp.FiniteElement

Create a FiniteElement of a given family, celltype, degree and lattice type

basix.create_lattice(arg0: basix::cell::type, arg1: int, arg2: basix._basixcpp.LatticeType, arg3: bool) numpy.ndarray[numpy.float64]

Create a uniform lattice of points on a reference cell

basix.geometry(arg0: basix::cell::type) numpy.ndarray[numpy.float64]

Geometric points of a reference cell

basix.index(*args, **kwargs)

Overloaded function.

  1. index(arg0: int) -> int

Indexing for 1D arrays

  1. index(arg0: int, arg1: int) -> int

Indexing for triangular arrays

  1. index(arg0: int, arg1: int, arg2: int) -> int

Indexing for tetrahedral arrays

basix.make_quadrature(arg0: str, arg1: basix._basixcpp.CellType, arg2: int) Tuple[numpy.ndarray[numpy.float64], numpy.ndarray[numpy.float64]]

Compute quadrature points and weights on a reference cell

basix.tabulate_polynomial_set(arg0: basix._basixcpp.CellType, arg1: int, arg2: int, arg3: numpy.ndarray[numpy.float64]) numpy.ndarray[numpy.float64]

Tabulate orthonormal polynomial expansion set

basix.topology(arg0: basix::cell::type) List[List[List[int]]]

Topological description of a reference cell

basix.cell

Functions to get cell geometry information and manipulate cell types.

basix.cell.facet_jacobians()

cell_facet_jacobians(arg0: basix._basixcpp.CellType) -> numpy.ndarray[numpy.float64]

Get the jacobians of the facets of a cell

basix.cell.facet_normals()

cell_facet_normals(arg0: basix._basixcpp.CellType) -> numpy.ndarray[numpy.float64]

Get the normals to the facets of a cell

basix.cell.facet_orientations()

cell_facet_orientations(arg0: basix._basixcpp.CellType) -> List[bool]

Get the orientations of the facets of a cell

basix.cell.facet_outward_normals()

cell_facet_outward_normals(arg0: basix._basixcpp.CellType) -> numpy.ndarray[numpy.float64]

Get the outward normals to the facets of a cell

basix.cell.facet_reference_volumes()

cell_facet_reference_volumes(arg0: basix._basixcpp.CellType) -> numpy.ndarray[numpy.float64]

Get the reference volumes of the facets of a cell

basix.cell.string_to_type(cell: str)

Convert a string to a Basix CellType.

basix.cell.sub_entity_connectivity(arg0: basix::cell::type) List[List[List[List[int]]]]

Connectivity between subentities of a reference cell

basix.cell.type_to_string(celltype: basix._basixcpp.CellType)

Convert a Basix CellType to a string.

basix.cell.volume()

cell_volume(arg0: basix._basixcpp.CellType) -> float

Get the volume of a cell

basix.finite_element

Functions for creating finite elements.

basix.finite_element.string_to_family(family: str, cell: str)

Get a Basix ElementFamily enum representing the family type on the given cell.

basix.lattice

Functions to create lattices and manipulate lattice types.

basix.lattice.string_to_type(lattice: str)

Convert a string to a Basix LatticeType enum.

basix.lattice.type_to_string(latticetype: basix._basixcpp.LatticeType)

Convert a Basix LatticeType enum to a string.

basix.numba_helpers