Build the standard finite element stiffness matrix for a diffusion problem.
The equation taken into account is:
- div (epsilon * kappa grad (u)) = f
where epsilon is an element-wise constant scalar function, while kappa is a piecewise linear conforming scalar function.
See also: bim2a_rhs, bim2a_reaction, bim2a_advection_diffusion, bim1a_laplacian, bim3a_laplacian.
Package: bim