docs: public float rSum(float[] y, float[] w) {
      float tmp1 = (float) 0.0, tmp2 = (float) 0.0;
      for (int i = 0; i < y.length; i++) {
        tmp1 += y[i] * w[i];
        tmp2 += w[i];
      }
  
      return correctTo01(tmp1 / tmp2);
    }