Which function do I need?

Find what your code does in the first column. The last column says which DOLFINx versions behave differently, which is when the function matters. “None” means the native call is the same from 0.10 on, and the function is only a convenience. For things that need no function at all, see Already the same on every version.

Meshes

If your code needs to	Use	Differs between
Create a mesh from arrays with a ghost mode	create_mesh	0.10, 0.11 / main
Create a mesh from a gmsh model with a ghost mode	model_to_mesh	0.10, 0.11 / main
Pass a ghosted partitioner to an API that takes no ghost mode	create_cell_partitioner	0.10, 0.11 only; raises on main
Change the degree of the coordinate element	reconstruct_mesh	0.10 / 0.11, main
Get the coordinate element	cmap	0.10 / 0.11, main
Get the nodes of each cell	dofmap	0.10 / 0.11, main
Get the topology of a MeshTags as the Python object	meshtags_topology	0.10, 0.11 / main
Get the cell permutation info	cell_permutation_info	0.10, 0.11 / main
Get the orientation of each facet as seen from each cell	facet_permutations	0.10, 0.11 / main
Create a Raviart-Thomas space on a manifold	create_facet_orientations	0.10, 0.11 / main
Move tags from a mesh to a submesh	transfer_meshtags_to_submesh	0.10 / 0.11 / main

Index maps and vectors

If your code needs to	Use	Differs between
Create an index map	create_index_map	0.10, 0.11 / main
Pass an index map to a dolfinx.cpp function	unwrap_index_map	0.10, 0.11 / main
Create an index map for a subset of indices	create_sub_index_map	0.10, 0.11 / main
Find the other ranks that hold each index	index_to_dest_ranks	0.10, 0.11 / main
Split range(N) over ranks the way DOLFINx does	local_range	0.10, 0.11 / main
Create a dolfinx.la.Vector	vector	None, if dtype is a keyword

Function spaces, elements and interpolation

If your code needs to	Use	Differs between
Create a real (global constant) function space	real_functionspace	0.10 / 0.11, main
Create a C++ finite element	finite_element_ctor_kwargs	0.10, 0.11 / main
Interpolate values already evaluated at the interpolation points	interpolate	0.10 / 0.11, main
Evaluate an expression on cells or facets	expression_eval	None
Create an expression that uses coefficients from a parent mesh	interpolate_to_submesh_entity_maps	0.10 / 0.11, main
Evaluate on facets at points seen from the cell	permute_facet_quadrature	0.10 / 0.11, main
Reorder facet values to the facet’s own orientation	permute_interpolation_data	0.10 / 0.11, main

Forms and PETSc

If your code needs to	Use	Differs between
Get the index map and block size of a linear form	form_map	0.10 / 0.11, main
Sort boundary conditions by block	bcs_by_block	0.10, 0.11 / main, when spaces are mixed
Set Dirichlet values in a PETSc vector	set_bc	None
Apply lifting and set Dirichlet values in one call	apply_lifting_and_set_bc	None
Zero a PETSc vector, or update its ghosts	zero_petsc_vector, ghost_update	None

UFL

If your code needs to	Use	Differs between
Get the domain of an expression	domain_of	None
Map an expression back to the reference cell	apply_pullback_inverse	0.10, 0.11 / main

Output and other packages

If your code needs to	Use	Differs between
Get the VTK cell type of a mesh cell	vtk_cell_type	0.10, 0.11 / main
Get ADIOS2’s low-level bindings	resolve_adios_scope	ADIOS2 2.9 / 2.10 and newer
Let PyVista use VTK’s snake_case names	pyvista_allow_snake_case	PyVista 0.45, 0.46 / 0.47 and newer
Branch on the DOLFINx version	at_least, before	None
Import an optional module with a helpful error	require_module	None