Class SVR_Q

ml/src/svm.cpp:1552–1635

};

class SVR_Q : public Kernel {

public:
  SVR_Q(const svm_problem& prob, const svm_parameter& param)
  : Kernel(prob.l, prob.x, param)
  {
    l = prob.l;
    cache = new Cache(l, static_cast<long int>(param.cache_size * (1 << 20)));
    QD = new double[2 * l];
    sign = new schar[2 * l];
    index = new int[2 * l];

    for (int k = 0; k < l; k++) {
      sign[k] = 1;
      sign[k + l] = -1;
      index[k] = k;
      index[k + l] = k;
      QD[k] = (this->*kernel_function)(k, k);
      QD[k + l] = QD[k];
    }

    buffer[0] = new Qfloat[2 * l];

    buffer[1] = new Qfloat[2 * l];
    next_buffer = 0;
  }

  void
  swap_index(int i, int j) const override
  {
    swap(sign[i], sign[j]);
    swap(index[i], index[j]);
    swap(QD[i], QD[j]);
  }

  Qfloat*
  get_Q(int i, int len) const override
  {
    Qfloat* data;
    int j, real_i = index[i];

    if (cache->get_data(real_i, &data, l) < l) {
      for (j = 0; j < l; j++)
        data[j] = static_cast<Qfloat>((this->*kernel_function)(real_i, j));
    }

    // reorder and copy
    Qfloat* buf = buffer[next_buffer];

    next_buffer = 1 - next_buffer;

    schar si = sign[i];

    for (j = 0; j < len; j++)
      buf[j] = static_cast<Qfloat>(si) * static_cast<Qfloat>(sign[j]) * data[index[j]];

    return buf;
  }