| 51 | } |
| 52 | |
| 53 | double DCGCalculator::CalMaxDCGAtK(data_size_t k, const label_t* label, data_size_t num_data) { |
| 54 | double ret = 0.0f; |
| 55 | // counts for all labels |
| 56 | std::vector<data_size_t> label_cnt(label_gain_.size(), 0); |
| 57 | for (data_size_t i = 0; i < num_data; ++i) { |
| 58 | ++label_cnt[static_cast<int>(label[i])]; |
| 59 | } |
| 60 | int top_label = static_cast<int>(label_gain_.size()) - 1; |
| 61 | |
| 62 | if (k > num_data) { k = num_data; } |
| 63 | // start from top label, and accumulate DCG |
| 64 | for (data_size_t j = 0; j < k; ++j) { |
| 65 | while (top_label > 0 && label_cnt[top_label] <= 0) { |
| 66 | top_label -= 1; |
| 67 | } |
| 68 | if (top_label < 0) { |
| 69 | break; |
| 70 | } |
| 71 | ret += discount_[j] * label_gain_[top_label]; |
| 72 | label_cnt[top_label] -= 1; |
| 73 | } |
| 74 | return ret; |
| 75 | } |
| 76 | |
| 77 | void DCGCalculator::CalMaxDCG(const std::vector<data_size_t>& ks, |
| 78 | const label_t* label, |