public DoubleAxesGroup CreateAbsoluteGroup(DoubleAxisParameter parameter)
 {
     // relative?
     _isRelative = false;
     _parameter = parameter;
     return DoCreateAbsoluteGroup();
 }
 public DoubleAxesGroup CreateRelativeGroup(AxisFormat axisFormat)
 {
     _isRelative = true;
     _parameter = new DoubleAxisParameter("%", 0, 100, axisFormat);
     return DoCreateAbsoluteGroup();
 }