Public List<double>

[KDTrade]

Hello, I'm trying to make a list of historical swing highs available for use in other indicators using List<double>, however I'm getting serious problems with my code returning an empty List, any idea what's wrong with my code, the current code returns no errors.

For reference, 'HighLow.prevHighs' is an example of the List that contains all previous swing highs (which works, I checked) and I want to copy it to the new List<double> 'highs' to easily reference it.

namespace NinjaTrader.NinjaScript.Indicators
{
public class ASR2 : Indicator
{
private HighLow highlow;
List<double> highs = new List<double>();
List<double> lows = new List<double>();


private double avgRes;
private double avgSupp;

protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
Description = @"";
Name = "ASR2";
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;
Swing = 5;
SwingsToStore = 5;
AddPlot(Brushes.Green, "Resistance");
AddPlot(Brushes.Red, "Support");
}
else if (State == State.Configure)
{
}
else if (State == State.DataLoaded)
{
highlow = HighLow(Swing, SwingsToStore);
highs = HighLow(Swing, SwingsToStore).prevHighs;
lows = HighLow(Swing, SwingsToStore).prevLows;
}
}

protected override void OnBarUpdate()
{
Resistance[0] = (highlow.CurrentHigh[0] + highs[0]) / (2);
//Support[0] = (highlow.CurrentLow[0] + highlow.prevLows.Sum()) / (SwingsToStore + 1);
}

region Properties
[NinjaScriptProperty]
[Range(1, int.MaxValue)]
[Display(Name="Swing", Order=1, GroupName="Parameters")]
public int Swing
{ get; set; }

[NinjaScriptProperty]
[Range(1, int.MaxValue)]
[Display(Name="Swings To Store", Order=2, GroupName="Parameters")]
public int SwingsToStore
{ get; set; }

[Browsable(false)]
[XmlIgnore]
public Series<double> Resistance
{
get { return Values[0]; }
}

[Browsable(false)]
[XmlIgnore]
public Series<double> Support
{
get { return Values[1]; }
}
#endregion

}
}

[NinjaTrader_ChelseaB]

Hello KDTrade,

You are assigning

highs = HighLow(Swing, SwingsToStore).prevHighs;

When the script starts.

This is not a reference to the object in the indicator this is a copy of the object. You have copied an empty list from the indicator which has not processed any data yet, to 'highs'. 'highs' now has an empty list. It will not be updated when the original list is updated as they are separate objects.

That said, why not just use the original list? Copying this to another variable is redundant when the original list can already be accessed by a variable from the indicator.

I would assign HighLow to a variable.

In the scope of the class:

private HighLow myHighLow;

In State.DataLoaded:

myHighLow = HighLow(Swing, SwingsToStore);

In OnBarUpdate() where you need to access the values from the list:

for (int index = 0; index < myHighLow.prevHighs; index++)
{
Print(string.Format("myHighLow.prevHigh[{1}]: {2}", index, myHighLow.prevHigh[index]));
}

[KDTrade]

Hi Chelsea,

Here's a sample of the updated code

Resistance[0] = (highlow.CurrentHigh[0] + highlow.prevHighs[0]) / (2);

This code returns nothing on my chart despite there being no errors, any ideas are welcome.

Thanks,
KD

[KDTrade]

Never mind, I found the error in the code, it was an index out of range error.

[grimmer01]

Hi All, KDTrade, I came across the same type of error, "index out of range", how did you fix that? Thanks!

[NinjaTrader_ChelseaB]

Hello grimmer01,

Below is a link to a forum post on indexing errors.

https://ninjatrader.com/support/forum/forum/ninjatrader-8/indicator-development/1046200-indicator-that-calculate-in-different-chartime?p=1048513#post1048513