13   void add(
const double& x, 
const double& y) 
 
   52 add(
const double& x, 
const double& y)
 
   74   return m_data->m_x.numElements();
 
   80   return m_data->m_x.getAverage();
 
   86   return m_data->m_y.getAverage();
 
   92   return m_data->m_x2.getAverage();
 
   98   return m_data->m_y2.getAverage();
 
  104   return m_data->m_xy.getAverage();
 
  110   return averageX2() - 2*averageXY() + averageY2();
 
  116   return averageX2() - averageX()*averageX()
 
  117     -2*(averageXY() - averageX()*averageY())
 
  118     + averageY2() - averageY()*averageY();
 
  124   return (averageXY() - averageX()*averageY())
 
  125     / sqrt((averageX2() - averageX()*averageX())
 
  126            * (averageY2() - averageY()*averageY()));
 
  130 fitting(
double &a, 
double &b, 
double &residual)
 const 
  132   double d = averageX2() - averageX()*averageX();
 
  133   double n = averageXY() - averageX()*averageY();
 
  134   if (std::abs(d) < 1e-8) {
 
  137     residual = averageY2() - averageY()*averageY();
 
  141   b = (averageX2()*averageY() - averageXY()*averageX()) / d;
 
  142   residual = averageY2()-averageY()*averageY()