C++ (Cpp) RieszRepPtr::getNorm Examples

Example #1

File: FiniteDifferenceUtilities.cpp Project: CamelliaDPG/Camellia

double FiniteDifferenceUtilities::finiteDifferenceGradient(MeshPtr mesh, RieszRepPtr residual, TSolutionPtr<double> backgroundSoln, int dofIndex)
{
  residual->computeRieszRep();
  double fx =  residual->getNorm();

  TSolutionPtr<double> solnPerturbation = TestingUtilities::makeNullSolution(mesh);

  // create perturbation in direction du
  solnPerturbation->clear(); // clear all solns
  TestingUtilities::initializeSolnCoeffs(solnPerturbation);
  TestingUtilities::setSolnCoeffForGlobalDofIndex(solnPerturbation,1.0,dofIndex);
  double h = 1e-7;
  backgroundSoln->addSolution(solnPerturbation,h);

  residual->computeRieszRep();
  double fxh = residual->getNorm();
  // get 1/2 squared norm (cost function) for each quantity
  double f = fx*fx*.5;
  double fh = fxh*fxh*.5;
  double fd_gradient = (fh-f)/h;

  // remove contribution
  backgroundSoln->addSolution(solnPerturbation,-h);

  return fd_gradient;
}