inv_mass(3) invert of L2 scalar product


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


Assembly the invert of the matrix associated to the L2 scalar product of the finite element space V:

        m(u,v) = | u v dx
                 / Omega

The V space may be either a P0 or P1d discontinuous finite element spaces see form(2).


The following piece of code build the invert of the mass matrix associated to the P1d approximation:

        geo omega_h ("square");
        space Vh (omega_h , "P1d");
        form im (Vh, Vh, "inv_mass");