sfepy.discrete.common.extmods.cmesh module

C Mesh data structures and functions.

class sfepy.discrete.common.extmods.cmesh.CConnectivity

Notes

The memory is allocated/freed in C - this class just wraps NumPy arrays around that data without copying.

cprint()
indices
n_incident
num
offset
offsets
class sfepy.discrete.common.extmods.cmesh.CMesh
cell_groups
cell_types
conns
coors
cprint()
create_new()

Create a new CMesh instance, with cells corresponding to the given entities of dimension dent.

Parameters:
entities : array, optional

The selected topological entities of the mesh to be in the new mesh. If not given, a copy of the mesh based on the cell-vertex connectivity is returned.

dent : int, optional

The topological dimension of the entities.

localize : bool

If True, strip the vertices not used in the the resulting sub-mesh cells and renumber the connectivity.

Returns:
cmesh : CMesh

The new mesh with the cell-vertex connectivity. Other connectivities have to be created and local entities need to be set manually.

dim
edge_oris
entities
face_oris
facet_oris
free_connectivity()
from_data()

Fill CMesh data using Python data.

get_cell_conn()
get_centroids()

Return the coordinates of centroids of mesh entities with dimension dim.

get_complete()

Get entities of dimension dim that are completely given by entities of dimension dent listed in entities.

get_conn()
get_conn_as_graph()

Get d1 -> d2 connectivity as a sparse matrix graph (values = ones).

For safety, creates a copy of the connectivity arrays. The connectivity is created if necessary.

get_facet_normals()

Return the normals of facets for each mesh cell. The normals can be accessed using the cell-facet connectivity.

If which is -1, two normals of each quadrilateral face are averaged. If it is 0 or 1, the corresponding normal is used.

get_incident()

Get non-unique entities indices of dimension dim that are contained in entities of dimension dent listed in entities. As each of entities can be in several entities of dimension dent, offsets array is returned optionally.

get_local_entities()
get_local_ids()

Get local ids of entities of dimension dent in non-unique entities incident of dimension dim (with given offsets per entities) incident to entities, see mesh_get_incident().

The function searches entities in incident -> entities connectivity for each non-unique entity in incident.

get_orientations()

Get orientations of entities of dimension dim. Alternatively, co-dimension can be specified using codim argument.

get_surface_facets()

Get facets (edges in 2D, faces in 3D) on the mesh surface.

get_volumes()

Return the volumes of mesh entities with dimension dim > 0.

key_to_index
n_coor
n_el
num
set_local_entities()
setup_connectivity()
setup_entities()

Set up mesh edge (2D and 3D) and face connectivities (3D only) as well as their orientations.

tdim
vertex_groups
sfepy.discrete.common.extmods.cmesh.cmem_statistics()
sfepy.discrete.common.extmods.cmesh.create_mesh_graph()

Create sparse (CSR) graph corresponding to given row and column connectivities.

Parameters:
n_row : int

The number of row connectivity nodes.

n_col : int

The number of column connectivity nodes.

n_gr : int

The number of element groups.

rconns : list of arrays

The list of length n_gr of row connectivities.

cconns : list of arrays

The list of length n_gr of column connectivities.

Returns:
nnz : int

The number of graph nonzeros.

prow : array

The array of CSR row pointers.

icol : array

The array of CSR column indices.

sfepy.discrete.common.extmods.cmesh.get_cmem_usage()
sfepy.discrete.common.extmods.cmesh.graph_components()

Determine connected compoments of a compressed sparse graph.

Returns:
n_comp : int

The number of components.

flag : array

The flag marking for each node its component.

sfepy.discrete.common.extmods.cmesh.orient_elements()

Swap element nodes so that its volume is positive.