Assigning different physical groups to different color in gmsh and mark them as different material in fenics

[dokken]

The problem is that the msh file does not store any of the information regarding your image, and thus you have lost all the information you started with.

You could do something like:

How to define a subdomain using material data (from data file)?

First of all, does your mesh consist of triangles or quadrilaterals? Secondly, is your mesh uniform and structured (i.e. is it a RectangleMesh with 100 x 100 cells?) I would suggest something like: from dolfin import * import numpy as np mesh = UnitSquareMesh(100, 100) V = FunctionSpace(mesh, "DG", 0) u = Function(V) dx = 1/100 values = np.arange(100*100) local_values = np.zeros_like(u.vector().get_local()) for cell in cells(mesh): midpoint = cell.midpoint().array() i = int(midpoi…

with some slight modifications.