Grouping the cells

dolfinx
1

Hello everyone,
I would like to know how I can group the cells in a mesh in dolfinx. This way, instead of taking one cell, I can consider a group of cells.
I really appreciate any help you can provide.

2

What do you imply when you say grouping? What kind of operation would you like to apply on the group?

3

I am trying to coarsen the mesh. So I want to find the cells where it has value by creating groups. In this way, I can refer to the collection of cells having that particular value instead of looking for each ell.

4

This is still very abstract. You can get indices of groups of cells by for instance using a marking function

def marker_func(x):
     # Create some criterion based on the vertices of the cells
     criterion = # some numpy array with true_false values of the same size as x.shape[1]
     return criterion
cells = dolfinx.mesh.locate_entities(mesh, mesh.topology.dim, marker_func)
5

Thank you, I will take a look at this