Can't solve this error

[tjendra]

I am trying to print the highest ATR value over a certain period. But I get this Operator '*' cannot be applied to operands of type 'double' and 'NinjaTrader.NinjaScript.Indicators.ATR' error which I can't solve.


I add the following code to the indicator code generated by the wizard:

private double TS;

ATR_Period = 5;
HHV_Period = 10;
Multiplier = 2.5;

TS = MAX(High - Multiplier * ATR(ATR_Period),HHV_Period);

[iq200]

The reason is that ATR is returned as an array of atr values of the previous bars.. SO you need to do something like
ATR(ATR_Period)[0] to get the value of the current bar. Try:

TS = MAX(High - Multiplier * ATR(ATR_Period)[0],HHV_Period);

[tjendra]

Thanks iq200, but I still get Operator '-' cannot be applied to operands of type 'NinjaTrader.NinjaScript.ISeries<double>' and 'double' error.

I also tried TS = MAX(High[0] - Multiplier * ATR(ATR_Period)[0], HHV_Period); and TS = MAX(High[0] - Multiplier * ATR(ATR_Period)[0],HHV_Period)[0]; Both also doesn't work. I will get The best overloaded method match for 'NinjaTrader.NinjaScript.Indicators.Indicator.MAX( NinjaTrader.NinjaScript.ISeries<double>, int)' has some invalid arguments and Argument 1: cannot convert from 'double' to 'NinjaTrader.NinjaScript.ISeries<double>' errors.

[iq200]

Sorry my mistake. so MAX is an indicator/fn that takes in an array of values. I just realized MAX does a lookback.
So in your first instance you were trying to multiply a vector (which is what you need) by a scalar value. That was the reason for the error.

So what you will need to do is to create a Series array of High - Multiplier * ATR(ATR_Period) and pass this into MAX.

[iq200]

You will need to create an array such as:
private Series<double> myScaledATR;

Once you have instantiated the array using new, in your update fn, you need to do something like:

myScaledATR[0] = High[0] - Multiplier * ATR(ATR_Period)[0];

TS = MAX(myScaledATR, HHV_Period);

[tjendra]

Thanks iq200. I need to write TS = MAX(myScaledATR, HHV_Period)[0]; to compile correctly. But somehow the indicator doesn't load. I got Indicator 'ATRTrend': Error on calling 'OnBarUpdate' method on bar 30: Object reference not set to an instance of an object error. I tried putting if(CurrentBar<30) return; code in but it still didn't work. Attached the full code below.

[iq200]

Like I said, you need to instatiate your Series array:

protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
Description = @"ATR Trend";
Name = "ATRTrend";
Calculate = Calculate.OnBarClose;
IsOverlay = true;
DisplayInDataBox = true;
DrawOnPricePanel = true;
DrawHorizontalGridLines = true;
DrawVerticalGridLines = true;
PaintPriceMarkers = true;
ScaleJustification = NinjaTrader.Gui.Chart.ScaleJustification.Right;
//Disable this property if your indicator requires custom values that cumulate with each new market data event.
//See Help Guide for additional information.
IsSuspendedWhileInactive = true;
ATR_Period = 5;
HHV_Period = 10;
Multiplier = 2.5;
AddPlot(new Stroke(Brushes.SpringGreen, 2), PlotStyle.Dot, "Lower");

}
else if (State == State.Configure)
{
}
else if (State == State.DataLoaded)
{
Plotset = new Series<double>(this);
}
}

[NinjaTrader_Kate]

Hello tjendra,

Thank you for your post.

I apologize for my delayed reply as I got stuck on a call, but iq200 is doing a great job here. Do you still get an error after instantiating your plot as seen above?

Thanks in advance, I look forward to assisting you further.

[tjendra]

Hi Kate, everything is working now. Thanks iq200 for your help!