Function assemble_vector0

cpp/demo/custom_kernel/main.cpp:103–117

/// @return l2 norm squared of the vector.
template <std::floating_point T>
double assemble_vector0(std::shared_ptr<const fem::FunctionSpace<T>> V,
                        auto kernel, const std::vector<std::int32_t>& cells)
{
  auto mesh = V->mesh();
  std::map integrals{
      std::pair{std::tuple{fem::IntegralType::cell, 0, 0},
                fem::integral_data<T>(kernel, cells, std::vector<int>{})}};
  fem::Form<T> L({V}, integrals, mesh, {}, {}, false, {});
  auto dofmap = V->dofmap();
  la::Vector<T> b(dofmap->index_map, 1);
  common::Timer timer("Assembler0 std::function (vector)");
  fem::assemble_vector(b.array(), L);
  b.scatter_rev(std::plus<T>());
  return la::squared_norm(b);
}

/// @brief Assemble a matrix operator using a lambda kernel function.
///