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An event driven method which is called while the chart scale is being updated.  This method is used to determine the highest and lowest value that can be used for the chart scale and is only called when the chart object is set to IsAutoScale.


Note:  The indexer used to look up a Series<T> value through barsAgo is NOT guaranteed to be in sync when the OnCalculateMinMax() method is called.  You will need to use GetValueAt() to obtain a historical value at a specified absolute index.



Method Return Value

This method does not return a value.


You must override the method in your NinjaScript object with the following syntax:

public override void OnCalculateMinMax()


Method Parameters

This method does not accept any parameters.




protected override void OnStateChange()
  if (State == State.SetDefaults)
    Name       = "Example Indicator";
    IsOverlay   = true;
    // set this to true to ensure CalculateMinMix() is called
    IsAutoScale = true;
public override void OnCalculateMinMax()
  // make sure to always start fresh values to calculate new min/max values
  double tmpMin = double.MaxValue;
  double tmpMax = double.MinValue;
  // For performance optimization, only loop through what is viewable on the chart
  for (int index = ChartBars.FromIndex; index <= ChartBars.ToIndex; index++)
    // since using Close[0] is not guaranteed to be in sync
    // retrieve "Close" value at the current viewable range index
    double plotValue = Close.GetValueAt(index);
    // return min/max of close value
    tmpMin = Math.Min(tmpMin, plotValue);
    tmpMax = Math.Max(tmpMax, plotValue);
  // Finally, set the minimum and maximum Y-Axis values to +/- 50 ticks from the primary close value
  MinValue = tmpMin - 50 * TickSize;
  MaxValue = tmpMax + 50 * TickSize;