API reference

class scifem.PointSource(V: FunctionSpace, points: ndarray[Any, dtype[float32]] | ndarray[Any, dtype[float64]], magnitude: floating | complexfloating = np.float64(1.0))

Class for defining a point source in a given function space.

apply_to_vector(b: Function | Vector | Vec, recompute: bool = False)

Apply the point sources to a vector.

Parameters:

• b – The vector to apply the point sources to.

• recompute – If the point sources should be recomputed before applying. Recomputation should only be done if the mesh geometry has been modified.

Note

The user is responsible for forward scattering of the vector after applying the point sources.

Note

If a PETSc vector is passed in, one has to call b.assemble() prior to solving the linear system (post scattering).

compute_cell_contributions()

Compute the basis function values at the point sources.

recompute_sources()

Recompute the what cells the point sources collide with.

This function should be called if the mesh geometry has been modified.

scifem.assemble_scalar(J: Form | Form) → floating | complexfloating

Assemble a scalar form and gather result across processes

Parameters:

form – The form to assemble.

Returns:

The accumulated value of the assembled form.

scifem.create_entity_markers(domain: dolfinx.mesh.Mesh, dim: int, entities_list: list[TaggedEntities]) → dolfinx.mesh.MeshTags

Mark entities of specified dimension according to a geometrical marker function.

Parameters:

• domain – A dolfinx.mesh.Mesh object

• dim – Dimension of the entities to mark

• entities_list –

  A list of tuples with the following elements:

  • index 0: The tag to assign to the entities

  • index 1: A function that takes a point and returns a boolean array indicating whether the point is inside the entity

  • index 2: Optional, if True, the entities will be marked on the boundary

Returns:

A dolfinx.mesh.MeshTags object with the corresponding entities marked. If an entity satisfies multiple input marker functions, it is not deterministic what value the entity gets.

Note:

scifem.create_real_functionspace(mesh: Mesh, value_shape: tuple[int, ...] = ()) → FunctionSpace

Create a real function space.

Parameters:

• mesh – The mesh the real space is defined on.

• value_shape – The shape of the values in the real space.

Returns:

The real valued function space.

Note

For scalar elements value shape is ().

scifem.dof_to_vertexmap(V: FunctionSpace) → ndarray[Any, dtype[int32]]

Create a map from the degrees of freedom to the vertices of the mesh. As not every degree of freedom is associated with a vertex, every dof that is not associated with a vertex returns -1

Parameters:

V – The function space

Returns:

An array mapping local dof i to a local vertex

scifem.evaluate_function(u: Function, points: Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | bool | int | float | complex | str | bytes | _NestedSequence[bool | int | float | complex | str | bytes], broadcast=True) → ndarray[Any, dtype[float64]]

Evaluate a function at a set of points.

Parameters:

• u – The function to evaluate.

• points – The points to evaluate the function at.

• broadcast –

  If True, the values will be broadcasted to all processes.

  Note

  Uses a global MPI call to broadcast values, thus this has to be called on all active processes synchronously.

  Note

  If the function is discontinuous, different processes may return different values for the same point. In this case, the value returned is the maximum value across all processes.

Returns:

The values of the function evaluated at the points.

scifem.transfer_meshtags_to_submesh(entity_tag: MeshTags, submesh: Mesh, vertex_to_parent: ndarray[Any, dtype[int32]], cell_to_parent: ndarray[Any, dtype[int32]]) → tuple[MeshTags, ndarray[Any, dtype[int32]]]

Transfer a entity_tag from a parent mesh to a submesh.

Parameters:

• entity_tag – Tag to transfer

• submesh – Submesh to transfer tag to

• vertex_to_parent – Mapping from submesh vertices to parent mesh vertices

• cell_to_parent – Mapping from submesh cells to parent entities

Returns:

submesh_tag is the tag on the submesh and sub_to_parent_entity_map is a mapping from submesh entities in the tag to the corresponding entities in the parent.

Return type:

A tuple (submesh_tag, sub_to_parent_entity_map) where

scifem.vertex_to_dofmap(V: FunctionSpace) → ndarray[Any, dtype[int32]]

Create a map from the vertices (local to the process) to the correspondning degrees of freedom.

Parameters:

V – The function space

Returns:

An array mapping local vertex i to local degree of freedom

Note

If using a blocked space this map is not unrolled for the DofMap block size.