grad_grad(3) -Laplacian operator


form(const space V, const space& V, "grad_grad");


Assembly the form associated to the Laplacian operator on a finite element space V:

      a(u,v) = |  grad(u).grad(v) dx
               / Omega

The V space may be a either P1 , P2 or P1d finite element space. See also form(2) and space(2).


The following piece of code build the Laplacian form associated to the P1 approximation:

        geo g("square");
        space V(g, "P1");
        form a(V, V, "grad_grad");