Method Backward

src/model/layer/dropout.cc:47–58

}

const std::pair<Tensor, vector<Tensor>> Dropout::Backward(int flag,
                                                          const Tensor& grad) {
  vector<Tensor> param_grad;
  Tensor input_grad;
  if (flag & kTrain) {
    // note mask is already scaled by 1/(1-dropout_ratio_)
    input_grad = grad * mask_;
  } else {
    LOG(ERROR) << "Do not call backward for evaluation phase";
  }
  return std::make_pair(input_grad, param_grad);
}

void Dropout::ToDevice(std::shared_ptr<Device> device) {
  Layer::ToDevice(device);