message: Allows constant coefficient for dim == 2 && sdim == 3 case
diff: @@ -217,7 +217,9 @@ void VectorDiffusionIntegrator::AssemblePA(const FiniteElementSpace &fes)
  auto J = Reshape(j.Read(), NQ, SDIM, DIM, ne);
  auto D = Reshape(d.Write(), NQ, SDIM, ne);
  - auto C = Reshape(coeff.HostWrite(), NQ, ne);
  + const bool const_c = coeff.Size() == 1;
  + const auto C = const_c ? Reshape(coeff.Read(), 1,1) :
  + Reshape(coeff.Read(), NQ,ne);
  MFEM_FORALL(e, ne,
  {
  @@ -234,7 +236,8 @@ void VectorDiffusionIntegrator::AssemblePA(const FiniteElementSpace &fes)
  const double G = J12*J12 + J22*J22 + J32*J32;
  const double F = J11*J12 + J21*J22 + J31*J32;
  const double iw = 1.0 / sqrt(E*G - F*F);
  - const double alpha = wq * C(q, e) * iw;
  + const double C1 = const_c ? C(0,0) : C(q,e);
  + const double alpha = wq * C1 * iw;
  D(q,0,e) = alpha * G; // 1,1
  D(q,1,e) = -alpha * F; // 1,2
  D(q,2,e) = alpha * E; // 2,2
  