thank you for answering thу question and sorry for the delay in communication. I am sorry for missing important point - i am in 3D space
In 2D HHO example it works fine since
# # Boundary selection
flst = m.outer_faces()
GAMMAD = 1
m.set_region(GAMMAD, flst)
managing with 1D faces that are the edges I suppose.
In 3D all_faces provides access to 2d faces. Consider 4 points simplex that have 4 faces. I can integrate over an area of one of faces or many using regions built with outer_faces output.
In my situation I have to make 1D integration over edges with respect to length. The 4 point simplex has 4 faces and 6 1D edges.
At first glance outer_faces() method doesn't provide access to 1D edges for 3D meshes and with is my problem, assuming the fact that it returns empty array for dim=1 or dim=2
boxm.outer_faces()
Out[:
array([[0, 0, 0, 0, 0, 0],
[0, 1, 2, 3, 4, 5]], dtype=int32)
boxm.outer_faces(3)
Out:
array([[0, 0, 0, 0, 0, 0],
[0, 1, 2, 3, 4, 5]], dtype=int32)
boxm.outer_faces(2)
Out: array([], shape=(2, 0), dtype=int32)
EMPTY
boxm.outer_faces(1)
Out: array([], shape=(2, 0), dtype=int32)
EMPTY
Here boxm is 1 convex rectangular
PARALLELEPIPED
Regards, Egor