SYNOPSIS

form(const space& V, const space& V, "lumped_mass");
form(const space& M, const space& V, "lumped_mass");
form (const space& V, const space& V, "lumped_mass", const domain& gamma);
form_diag(const space& V, "mass");

---

EXAMPLE

The use of lumped mass form write:

        form m(V, "lumped_mass");

or (see also mass(3)):

        form_diag md(V, "mass");

The lumped procedure sums all extra-diagonal terms on the diagonal: let us denote M the original mass matrix, then, the lumped mass matrix is the diagonal matrix defined by:

                    n
                   ----
                           M1(i,i) =  /    M(i,j)
                   ----
                    j=1