Some problems about solving coupling problem

[dokken]

If your meshes are separate objects, you do not really have a common interface, Even if the facets align.
See for instance

How to represent non-uniform first and second type boundary conditions?

First of all, your coordinates make no sense, as will never match with Please pay special attention to details before posting code. Your code is also way to complicated, introducing boundary meshes, sub meshes of boundary meshes etc. Here is a minimal working example of what you want to achieve: from dolfin import * import numpy as np mesh = UnitSquareMesh(4, 4) VT = FunctionSpace(mesh, "CG", 1) T_data = np.array([0, 50, 100, 150, 0]) T_coordinates = np.array([[0, 0], [0., 0.25], [0., 0.…

and other related posts, and please add a minimal reproducible example for any further posts