message: Update ex9pa.
diff: @@ -18,7 +18,7 @@ void AddDGIntegrators(BilinearForm &k, VectorCoefficient &velocity)
  double alpha = 1.0;
  double beta = -0.5;
  k.AddDomainIntegrator(new ConvectionIntegrator(velocity, -alpha));
  - // k.AddDomainIntegrator(new MassIntegrator);
  + k.AddDomainIntegrator(new MassIntegrator);
  k.AddInteriorFaceIntegrator(
  new TransposeIntegrator(new DGTraceIntegrator(velocity, alpha, beta)));
  k.AddBdrFaceIntegrator(
  @@ -515,12 +515,21 @@ int main(int argc, char *argv[])
  AddDGIntegrators(k_test, velocity);
  AddDGIntegrators(k_ref, velocity);
  + tic_toc.Clear();
  + tic_toc.Start();
  k_test.Assemble();
  k_test.Finalize();
  + tic_toc.Stop();
  + cout << "test assembly time: " << tic_toc.RealTime() << " sec." << endl;
  + tic_toc.Clear();
  + tic_toc.Start();
  k_ref.Assemble();
  + k_ref.Finalize();
  + tic_toc.Stop();
  + cout << "ref assembly time: " << tic_toc.RealTime() << " sec." << endl;
  - std::cout << "FA matrix:" << std::endl;
  - std::cout << k_ref.SpMat() << std::endl;
  + // std::cout << "FA matrix:" << std::endl;
  + // std::cout << k_ref.SpMat() << std::endl;
  GridFunction u(&fes), r_test(&fes), r_ref(&fes), diff(&fes);
  //u.ProjectCoefficient(u0);
  