private DataRange CalculateRange(double value)
        {
            DataRange axisRange = new DataRange(this.ChartArea.AxisY.ActualMinValue, this.ChartArea.AxisY.ActualMaxValue);

            double    itemY           = axisRange.Normalize(value);
            double    zero            = axisRange.Normalize(0d);
            DataRange restrictedRange = new DataRange(DataRange.Unit.Restrict(zero), itemY);

            return(DataRange.Unit.Invert(restrictedRange));
        }