How to create MQL5 Keltner Channel programmatically

Question

I'm trying to create/use Keltner Channel indicator in my MQL5 Expert Advisor but for some reason it is not working. I know that at the moment MQL5 doesn't have a built-in indicator, so I am trying to manually create one using the following code, can anyone please assist in fixing the problem:

    In the OnInit() function:
    int bars = iBars(NULL, TimeFrame);
    ArrayResize(upperKeltner, bars);
    ArrayResize(lowerKeltner, bars);
    
    double atr = iATR(_Symbol, _Period, 14);
    for(int i = 0; i < count; i++)
    {
        double typical_price = (iOpen(_Symbol, _Period, i) + iHigh(_Symbol, _Period, i) + iLow(_Symbol, _Period, i)) / 3.0;
        upperKeltner[i] = typical_price + atr * 1.5;
        lowerKeltner[i] = typical_price - atr * 1.5;
    }
    
    In the OnTick() function:
    ArrayResize(upperKeltner, 1);
    ArrayResize(lowerKeltner, 1);
    CopyBuffer(handleKeltner, 0, 0, 1, upperKeltner);
    CopyBuffer(handleKeltner, 1, 0, 1, lowerKeltner);

Answer 1

To create a indicator, you has to place the code in the OnCalculate function.

What error is happening?

In the CodeBase already has the Indicator. https://www.mql5.com/pt/code/16740