Calculates the potential generated due a dipole in concentric spheres with bilinear basis functions. The inner sphere has unit radius and the outer sphere a radius of 2. There is a conductivity of 0.3 in the inner sphere and 0.2 in the outer sphere.

The numerical solution is compared to the analytic solution.

The output for the mesh with discretisation 16x16 is also given and can be visualised using draw.com. The potential field on the inner and outer spheres is shown below.

innersphere outersphere