Create a 1D mesh in a 2D space

[dokken]

@RemDelaporteMathurin

I can restrict it to facets of the 2D mesh yes. Would it raise an error if I try to make a 1D submesh if it doesn’t match?

No, there would just be no cells in the submesh, ie the entity list you send into create_submesh would be empty.

@RemDelaporteMathurin

Ok so this not a good route then?

I wouldn’t recommend it. For intervals, it is quite easy to make custom meshes, see for instance

Connect 1D domains

It is quite straightforward: from mpi4py import MPI import ufl import basix.ufl import numpy as np import dolfinx c_el = basix.ufl.element("Lagrange", basix.CellType.interval, 1, shape=(2,)) N = 4 M = 7 L = 5 l0 = np.linspace(-1, 0, N) l1 = np.linspace(0, 1, M)[1:] l2 = np.linspace(0, 1, L)[1:] nodes = np.zeros((N + M - 1 + L - 1, 2), dtype=np.float64) nodes[:N, 0] = l0 nodes[N : N + M - 1, 1] = l1 nodes[N + M - 1 :, 0] = l2 connectivity = np.full(((N - 1 + M - 1 + L - 1), 2), -1, dtype=np.i…