Integrator for laplacian plus constant

[nilsfriess]

Hi, I'm currently playing around with mfem and right now I'm trying to setup a simple FE discretisation for the differential operator -Delta u + k^2 I, where I is the identity. What would be the best approach to create a mfem::BilinearForm for this operator?

[tzanio]

   double k = 4.0;

   ConstantCoefficient one(1.0);
   ConstantCoefficient kappa2(k*k);

   a.AddDomainIntegrator(new DiffusionIntegrator(one));
   a.AddDomainIntegrator(new MassIntegrator(kappa2));

[nilsfriess]

Thanks.