dolfinx.mesh

Creation, refining and marking of meshes

Functions

MeshTags(mesh, dim, indices, values)
create_mesh(comm, cells, x, domain[, …])	Create a mesh from topology and geometry data
locate_entities(mesh, dim, marker)	Compute list of mesh entities satisfying a geometric marking function.
locate_entities_boundary(mesh, dim, marker)	Compute list of mesh entities that are attached to an owned boundary facet and satisfy a geometric marking function.
refine(mesh[, cell_markers, redistribute])	Refine a mesh

dolfinx.mesh.MeshTags(mesh, dim, indices, values)

dolfinx.mesh.create_mesh(comm, cells, x, domain, ghost_mode=<GhostMode.shared_facet: 1>, partitioner=<built-in method partition_cells_graph of PyCapsule object>)

Create a mesh from topology and geometry data

dolfinx.mesh.create_meshtags(*args, **kwargs)

Overloaded function.

1. create_meshtags(arg0: dolfinx.cpp.mesh.Mesh, arg1: int, arg2: dolfinx::graph::AdjacencyList<int>, arg3: numpy.ndarray[numpy.int8]) -> dolfinx.cpp.mesh.MeshTags_int8

2. create_meshtags(arg0: dolfinx.cpp.mesh.Mesh, arg1: int, arg2: dolfinx::graph::AdjacencyList<int>, arg3: numpy.ndarray[numpy.int32]) -> dolfinx.cpp.mesh.MeshTags_int32

3. create_meshtags(arg0: dolfinx.cpp.mesh.Mesh, arg1: int, arg2: dolfinx::graph::AdjacencyList<int>, arg3: numpy.ndarray[numpy.float64]) -> dolfinx.cpp.mesh.MeshTags_double

4. create_meshtags(arg0: dolfinx.cpp.mesh.Mesh, arg1: int, arg2: dolfinx::graph::AdjacencyList<int>, arg3: numpy.ndarray[numpy.int64]) -> dolfinx.cpp.mesh.MeshTags_int64

dolfinx.mesh.locate_entities(mesh: dolfinx.cpp.mesh.Mesh, dim: int, marker: function)

Compute list of mesh entities satisfying a geometric marking function.

Parameters

• mesh – The mesh

• dim – The topological dimension of the mesh entities to consider

• marker – A function that takes an array of points x with shape (gdim, num_points) and returns an array of booleans of length num_points, evaluating to True for entities to be located.

Returns

Indices (local to the process) of marked mesh entities.

Return type

numpy.ndarray

dolfinx.mesh.locate_entities_boundary(mesh: dolfinx.cpp.mesh.Mesh, dim: int, marker: function)

Compute list of mesh entities that are attached to an owned boundary facet and satisfy a geometric marking function.

For vertices and edges, in parallel this function will not necessarily mark all entities that are on the exterior boundary. For example, it is possible for a process to have a vertex that lies on the boundary without any of the attached facets being a boundary facet. When used to find degrees-of-freedom, e.g. using fem.locate_dofs_topological, the function that uses the data returned by this function must typically perform some parallel communication.

Parameters

• mesh – The mesh

• dim – The topological dimension of the mesh entities to consider

• marker – A function that takes an array of points x with shape (gdim, num_points) and returns an array of booleans of length num_points, evaluating to True for entities to be located.

Returns

Indices (local to the process) of marked mesh entities.

Return type

numpy.ndarray

dolfinx.mesh.refine(mesh, cell_markers=None, redistribute=True)

Refine a mesh