void feature_pooling()

in caffe/tools/feature_pooling.cpp [240:310]
59 lines of code
17 McCabe index (conditional complexity)

void feature_pooling(vector<float>& features_pool, vector<data_item>& datas_pool,
    const vector<float>& features,	const vector<data_item>& datas) {
  int num = datas.size();
  int dim = features.size() / num;

  // pooling - label
  int N = num / FLAGS_number;
  datas_pool.resize(N);
  for (int i = 0; i < N; ++i) {
    datas_pool[i] = datas[i * FLAGS_number];
    datas_pool[i].id_ = i;
    for (int j = 1; j < FLAGS_number; ++j) {
      CHECK_EQ(datas_pool[i].label_, datas[i * FLAGS_number + j].label_)
          << "Label inconsistent";
    }
  }

  // pooling - feature
  features_pool.resize(N * dim);
  if (FLAGS_pooling == "max") {
    for (int i = 0; i < N; ++i) {
      for (int d = 0; d < dim; ++d) {
        features_pool[i * dim + d] = -1.0e20;
      }

      for (int j = 0; j < FLAGS_number; ++j) {
        int id = datas[i * FLAGS_number + j].id_;
        for (int d = 0; d < dim; ++d) {
          if (features[id * dim + d] > features_pool[i * dim + d])
            features_pool[i * dim + d] = features[id * dim + d];
        }
      }
    }
  } else if (FLAGS_pooling == "avg") {
    for (int i = 0; i < N; ++i) {
      for (int d = 0; d < dim; ++d) {
        features_pool[i * dim + d] = 0;
      }

      for (int j = 0; j < FLAGS_number; ++j) {
        int id = datas[i * FLAGS_number + j].id_;
        for (int d = 0; d < dim; ++d) {
          features_pool[i * dim + d] += features[id * dim + d];
        }
      }

      for (int d = 0; d < dim; ++d) {
        features_pool[i * dim + d] /= (float)FLAGS_number;
      }
    }
  } else {
    LOG(ERROR) << "Only support {max, avg} pooling : " << FLAGS_pooling;
  }

  if (!FLAGS_poolrst.empty()) {
    // dump the list files
    ofstream outfile;
    outfile.open(FLAGS_poolrst + "_datalist_" + FLAGS_pooling + "_pool.txt");
    for (int i = 0; i < N; ++i)
      outfile << datas_pool[i].name_ << " " << datas_pool[i].label_ << "\n";
    outfile.close();

    // dump the feature result
    outfile.open(FLAGS_poolrst + "_feature_" + FLAGS_pooling + "_pool.dat", ios::binary);
    outfile.write((const char*)(&N), sizeof(int));
    outfile.write((const char*)(&dim), sizeof(int));
    outfile.write((const char*)features_pool.data(), sizeof(float)*N * dim);

    outfile.close();
  }
}