ph-math/src/main/java/com/helger/numbercruncher/mathutils/RegressionLine.java
public void addDataPoint (final DataPoint dataPoint)
  {
    m_dSumX += dataPoint.getX ();
    m_dSumY += dataPoint.getY ();
    m_dSumXX += dataPoint.getX () * dataPoint.getX ();
    m_dSumXY += dataPoint.getX () * dataPoint.getY ();

    ++m_nDataPoints;
    m_bCoefsValid = false;
  }
public void addDataPoint (final DataPoint dataPoint)
  {
    m_dSumX += dataPoint.getX ();
    m_dSumY += dataPoint.getY ();
    m_dSumXX += dataPoint.getX () * dataPoint.getX ();
    m_dSumXY += dataPoint.getX () * dataPoint.getY ();

    ++m_nDataPoints;
    m_bCoefsValid = false;
  }
Add a new data point: Update the sums.

@param dataPoint
the new data point