Method Initialize

src/data/array_interface.h:406–446

* \brief Initialize the object, by extracting shape, stride and type. * * The function also perform some basic validation for input array. Lastly it will * also remove trivial dimensions like converting a matrix with shape (n_samples, 1) * to a vector of size n_samples. For for inputs like weights, this should be a 1 * dimension column vector even though user might provide

   *   dimension column vector even though user might provide a matrix.
   */
  void Initialize(Object::Map const &array) {
    ArrayInterfaceHandler::Validate(array);

    auto typestr = get<String const>(array.at("typestr"));
    this->AssignType(StringView{typestr});
    ArrayInterfaceHandler::ExtractShape(array, shape);
    std::size_t itemsize = typestr[2] - '0';
    is_contiguous = ArrayInterfaceHandler::ExtractStride(array, itemsize, shape, strides);
    n = linalg::detail::CalcSize(shape);

    data = ArrayInterfaceHandler::ExtractData(array, n);
    static_assert(allow_mask ? D == 1 : D >= 1, "Masked ndarray is not supported.");

    auto alignment = this->ElementAlignment();
    auto ptr = reinterpret_cast<uintptr_t>(this->data);
    if (!std::all_of(this->shape, this->shape + D, [](auto v) { return v == 0; })) {
      CHECK_EQ(ptr % alignment, 0) << "Input pointer misalignment.";
    }

    if (allow_mask) {
      common::Span<RBitField8::value_type> s_mask;
      size_t n_bits = ArrayInterfaceHandler::ExtractMask(array, &s_mask);

      valid = RBitField8(s_mask);

      if (s_mask.data()) {
        CHECK_EQ(n_bits, n) << "Shape of bit mask doesn't match data shape. "
                            << "XGBoost doesn't support internal broadcasting.";
      }
    } else {
      auto mask_it = array.find("mask");
      CHECK(mask_it == array.cend() || IsA<Null>(mask_it->second))
          << "Masked array is not yet supported.";
    }

    auto stream_it = array.find("stream");
    if (stream_it != array.cend() && !IsA<Null>(stream_it->second)) {
      int64_t stream = get<Integer const>(stream_it->second);
      ArrayInterfaceHandler::SyncCudaStream(stream);
    }
  }

 public:
  ArrayInterface() = default;