I tried to code an extremely simple thing this afternoon. In TS it would take me about 2 minutes to write. After 30 minutes, I am nowhere.

The idea is simple and something I might put into the FibRatioBand indicator and also was going to offer to Cory to experiment with in Volume Stop, which is actually why I thought of it.

The idea: if the Donchian Range x period is less than the ATR (period) * Multiplier, then the current swing range is too narrow for a volume stop (or in FibBand case, for a band target to be triggered).

Now how simple is that?

I cannot get the code to work the way I want it. I had no problem at all to code in:

ATR value changing color if narrower or wider than Donchian range.

But when I tried to have 2 plots for the Donchian range line, one 1 color if the swing is up and a different color when down, using a simple condition (if the EMA(period)[0] > EMA(period)[1]), although it compiles fine, it gets an error and won't plot.

Err msg: Error on calling the onbar update method ....index was out of range, must be non-negative and less than the size of the parameter name: index. Have no idea what that means.

And no idea what is wrong with my code.

Would be grateful if anyone could explain what it is I am doing wrong here. After one year with Ninja I still find problems like this doing the most simple of things and still cannot figure out why.

+++++++++++++++++++++++

PS. I have worked around the problem by using Slope(...) instead, but I would still appreciate learning why the original won't work, simple as it is. Attached is picture. I think Cory might find this useful for filtering out some of the volume stops in the additional patterns that are being worked on somewhere on the forum. It's not meant so much as an 'indicator' as a condition. I made it first into an indicator to see it, that's all.

+++++++++++++++++++++++

#region Using declarations
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Xml.Serialization;
using NinjaTrader.Cbi;
using NinjaTrader.Data;
using NinjaTrader.Gui.Chart;
#endregion

// This namespace holds all indicators and is required. Do not change it.
namespace NinjaTrader.Indicator
{
/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
[Description("Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.")]
public class ATRDonchian : Indicator
{
#region Variables
// Wizard generated variables
private int drange = 5; // Default setting for Drange
private double aTRMult = 2; // Default setting for ATRMult
private int aTRPeriod = 37; // Default setting for ATRPeriod
private double atrv = 0; // ATR value
private double drangev = 0; // Donchian range value
// User defined variables (add any user defined variables below)
#endregion

/// <summary>
/// This method is used to configure the indicator and is called once before any bar data is loaded.
/// </summary>
protected override void Initialize()
{
if (CurrentBar < ATRPeriod *2) return;

Add(new Plot(Color.FromKnownColor(KnownColor.Fuchsia), PlotStyle.Bar, "ATRnarrow"));
Add(new Plot(Color.FromKnownColor(KnownColor.LimeGreen), PlotStyle.Bar, "ATRwide"));
Add(new Plot(Color.FromKnownColor(KnownColor.DarkTurquoise), PlotStyle.Line, "Ddown"));
Add(new Plot(Color.FromKnownColor(KnownColor.Goldenrod), PlotStyle.Line, "Dup"));
CalculateOnBarClose = false;
Overlay = false;
PriceTypeSupported = false;
}

/// <summary>
/// Called on each bar update event (incoming tick)
/// </summary>
protected override void OnBarUpdate()
{
atrv = ATR(ATRPeriod)[0]*ATRMult;
drangev = DonchianChannel(drange).Upper[0] - DonchianChannel(drange).Lower[0];

if ( drangev <= atrv)
{ATRnarrow.Set(atrv);}
else ATRwide.Set(atrv);

//if (EMA(drange)[0] < EMA(drange)[1])

Ddown.Set(drangev);
//else
//Dup.Set(drangev);
}

#region Properties
[Browsable(false)] // this line prevents the data series from being displayed in the indicator properties dialog, do not remove
[XmlIgnore()] // this line ensures that the indicator can be saved/recovered as part of a chart template, do not remove
public DataSeries ATRnarrow
{
get { return Values[0]; }
}

[Browsable(false)] // this line prevents the data series from being displayed in the indicator properties dialog, do not remove
[XmlIgnore()] // this line ensures that the indicator can be saved/recovered as part of a chart template, do not remove
public DataSeries ATRwide
{
get { return Values[1]; }
}

[Browsable(false)] // this line prevents the data series from being displayed in the indicator properties dialog, do not remove
[XmlIgnore()] // this line ensures that the indicator can be saved/recovered as part of a chart template, do not remove
public DataSeries Ddown
{
get { return Values[2]; }
}

[Browsable(false)] // this line prevents the data series from being displayed in the indicator properties dialog, do not remove
[XmlIgnore()] // this line ensures that the indicator can be saved/recovered as part of a chart template, do not remove
public DataSeries Dup
{
get { return Values[3]; }
}

[Description("Donchian Period")]
[Category("Parameters")]
public int Drange
{
get { return drange; }
set { drange = Math.Max(1, value); }
}

[Description("ATR Multiplier")]
[Category("Parameters")]
public double ATRMult
{
get { return aTRMult; }
set { aTRMult = Math.Max(.1, value); }
}

[Description("Default ATR Period")]
[Category("Parameters")]
public int ATRPeriod
{
get { return aTRPeriod; }
set { aTRPeriod = Math.Max(1, value); }
}
#endregion
}
}

#region NinjaScript generated code. Neither change nor remove.
// This namespace holds all indicators and is required. Do not change it.
namespace NinjaTrader.Indicator
{
public partial class Indicator : IndicatorBase
{
private ATRDonchian[] cacheATRDonchian = null;

private static ATRDonchian checkATRDonchian = new ATRDonchian();

/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
/// <returns></returns>
public ATRDonchian ATRDonchian(double aTRMult, int aTRPeriod, int drange)
{
return ATRDonchian(Input, aTRMult, aTRPeriod, drange);
}

/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
/// <returns></returns>
public ATRDonchian ATRDonchian(Data.IDataSeries input, double aTRMult, int aTRPeriod, int drange)
{
checkATRDonchian.ATRMult = aTRMult;
aTRMult = checkATRDonchian.ATRMult;
checkATRDonchian.ATRPeriod = aTRPeriod;
aTRPeriod = checkATRDonchian.ATRPeriod;
checkATRDonchian.Drange = drange;
drange = checkATRDonchian.Drange;

if (cacheATRDonchian != null)
for (int idx = 0; idx < cacheATRDonchian.Length; idx++)
if (Math.Abs(cacheATRDonchian[idx].ATRMult - aTRMult) <= double.Epsilon && cacheATRDonchian[idx].ATRPeriod == aTRPeriod && cacheATRDonchian[idx].Drange == drange && cacheATRDonchian[idx].EqualsInput(input))
return cacheATRDonchian[idx];

ATRDonchian indicator = new ATRDonchian();
indicator.BarsRequired = BarsRequired;
indicator.CalculateOnBarClose = CalculateOnBarClose;
indicator.Input = input;
indicator.ATRMult = aTRMult;
indicator.ATRPeriod = aTRPeriod;
indicator.Drange = drange;
indicator.SetUp();

ATRDonchian[] tmp = new ATRDonchian[cacheATRDonchian == null ? 1 : cacheATRDonchian.Length + 1];
if (cacheATRDonchian != null)
cacheATRDonchian.CopyTo(tmp, 0);
tmp[tmp.Length - 1] = indicator;
cacheATRDonchian = tmp;
Indicators.Add(indicator);

return indicator;
}

}
}

// This namespace holds all market analyzer column definitions and is required. Do not change it.
namespace NinjaTrader.MarketAnalyzer
{
public partial class Column : ColumnBase
{
/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
/// <returns></returns>
[Gui.Design.WizardCondition("Indicator")]
public Indicator.ATRDonchian ATRDonchian(double aTRMult, int aTRPeriod, int drange)
{
return _indicator.ATRDonchian(Input, aTRMult, aTRPeriod, drange);
}

/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
/// <returns></returns>
public Indicator.ATRDonchian ATRDonchian(Data.IDataSeries input, double aTRMult, int aTRPeriod, int drange)
{
return _indicator.ATRDonchian(input, aTRMult, aTRPeriod, drange);
}

}
}

// This namespace holds all strategies and is required. Do not change it.
namespace NinjaTrader.Strategy
{
public partial class Strategy : StrategyBase
{
/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
/// <returns></returns>
[Gui.Design.WizardCondition("Indicator")]
public Indicator.ATRDonchian ATRDonchian(double aTRMult, int aTRPeriod, int drange)
{
return _indicator.ATRDonchian(Input, aTRMult, aTRPeriod, drange);
}

/// <summary>
/// Showing both ATR*multiplier and Donchian H-L range to compare. Can be used as condition for triggers in other methods.
/// </summary>
/// <returns></returns>
public Indicator.ATRDonchian ATRDonchian(Data.IDataSeries input, double aTRMult, int aTRPeriod, int drange)
{
if (InInitialize && input == null)
throw new ArgumentException("You only can access an indicator with the default input/bar series from within the 'Initialize()' method");

return _indicator.ATRDonchian(input, aTRMult, aTRPeriod, drange);
}

}
}
#endregion

Try this one (bad idea in initialize ).
Bad:

 

Code

protected override void Initialize() {     if (CurrentBar < ATRPeriod *2) return;

Better:

 

Code

protected override void OnBarUpdate() { if (CurrentBar < ATRPeriod *2)      return;

Sam thanks. I figured that out this morning. Am in a Ninja script slump right now. Everything I try to do is bass ackwards. I think it's because I was working with a little TS script over the weekend. Scrambled me.