Method GetTrace

fem/diffop.hpp:351–358

    virtual IntRange UsedDofs(const FiniteElement & fel) const override { return dim*diffop->UsedDofs(fel); }

    shared_ptr<DifferentialOperator> GetTrace() const override
    {
      if (auto diffoptrace = diffop->GetTrace())      
        return make_shared<BlockDifferentialOperatorTrans> (diffoptrace,
                                                            dim, comp);
      else
        return nullptr;
    }