Function MakeSubTensorCoefficientFunction

fem/coefficient.cpp:4829–4851

};

shared_ptr<CoefficientFunction>
MakeSubTensorCoefficientFunction (shared_ptr<CoefficientFunction> c1, int first, Array<int> num, Array<int> dist)
{
  //further optimization possible by checking if only subtensor of c1 is zero..
  if (c1->IsZeroCF())
    return ZeroCF(num);

  // trivial sub-tensor ?
  const auto dims = c1->Dimensions();
  bool trivial = (first == 0) && (num.Size() == dims.Size()) && (num == dims);
  for (int i = 0; i+1 < dist.Size(); i++)
    if (dist[i] != num[i]*dist[i+1]) trivial = false;
  if (dist.Size() >= 1)
    if (dist.Last() != 1) trivial = false;

  if (trivial)
    {
      cout << IM(5) << "optimizing out trivial sub-tensor" << endl;
      return c1;
    }
  
  return make_shared<SubTensorCoefficientFunction> (c1, first, std::move(num), std::move(dist));
}


shared_ptr<CoefficientFunction>