Method DiffJacobi

fem/coefficient.cpp:3564–3593

  }
  
  shared_ptr<CoefficientFunction> DiffJacobi (const CoefficientFunction * var, T_DJC & cache) const override
  {
    auto thisptr = const_pointer_cast<CoefficientFunction>(this->shared_from_this());
    if (cache.find(thisptr) != cache.end())
      return cache[thisptr];

    int h = Dimensions()[0];
    int dimvar = var->Dimension();

    if (this == var)
      return IdentityCF(h);

    Array<int> dimres{h};
    dimres += var->Dimensions();

    auto diffc1 = c1->DiffJacobi (var, cache);
    auto diffc2 = c2->DiffJacobi (var, cache);
    
    auto diffc1_trans = diffc1 -> TensorTranspose(0,1) -> Reshape(inner_dim, h*dimvar) -> Transpose();
    auto prod1 = (diffc1_trans * c2) -> Reshape(h,dimvar);
    auto prod1trans = prod1 -> Reshape(dimres);

    auto diffc2_trans = diffc2 -> Reshape(inner_dim, dimvar);
    auto prod2 = c1 * diffc2_trans;
    auto prod2trans = prod2 -> Reshape(dimres);

    auto res = prod1trans + prod2trans;
    cache[thisptr] = res;
    return res;
  }
  
};