private int convertToPanelX(double xval){
  double temp=(xval - m_minX) / m_rangeX;
  temp=temp * m_panelWidth;
  return (int)temp;
}

private int convertToPanelX ( double xval ) { double temp = ( xval - m_minX ) / m_rangeX ; temp = temp * m_panelWidth ; return ( int ) temp ; }
convert an x coordinate from the instance space to the panel space .
