Bar index needs to be greater/equal 0

[arnonmoscona]

This is very odd.

I have a multi-instrument indicator, and at some point in the code I have a call that occurs when BarsInProgress==0

This code tries to look at the series of other instruments and is looking for a matching timestamp. Skipping some code, here's the context of the problem:

//...
ITimeSeries time = Times[instrumentIndex];
//...
for (int i = 0; i < time.Count; i++)
{

//...
Print("i=" + i+", time.Count = "+time.Count); // debugging
DateTime t = time[i];
Print(" time = " + t); // debugging
// do stuff with t....

}

This works for some bars, but at some point it throws an exception. The output window shows the following:

...
i=390, time.Count = 1556
time = 6/6/2012 6:32:00 AM
i=391, time.Count = 1556
time = 6/6/2012 6:31:00 AM
i=392, time.Count = 1556
Exception in MyGroupWatchListVsIndex.OnBarUpdate(): System.ArgumentException: Bar index needs to be greater/equal 0
at NinjaTrader.Data.Bars.GetTime(Int32 barIndex)
at NinjaTrader.Data.Bars.GetTimeEnd(Int32 barIndex)
at NinjaTrader.Indicator.TimeSeriesHelper.get_Item(In t32 barsAgo)
at NinjaTrader.Indicator.MyGroupWatchListVsIndex.Find OffsetByTimestamp(DateTime syncTimeStamp, Int32 instrumentIndex, Boolean roundToDate, Boolean useExactMatch, Int32 guess) in c:\Users\Admin\Documents\NinjaTrader 7\bin\Custom\Indicator\MyGroupWatchListVsIndex.cs: line 327
...

So it's trying to access Times[instrumentIndex][392] when the series has 1556 items. As i understand this, this should not blow up... Plus the index is clearly positive.

What gives?

[NinjaTrader_AdamP]

arnonmoscona,

Do you perhaps have a toy sample I could use for testing that exhibits this same behavior?

[arnonmoscona]

Not really... It'll take some work probably.
Have you seen before this situation where a positive index causes this exception?

[NinjaTrader_AdamP]

arnon,

I have not. I am wondering if the error is from somewhere else here and so I wanted to take a look through the code.

A try/catch can be used to identify the exact line this is coming from in your Tools > Output window.

http://www.ninjatrader.com/support/forum/showthread.php?t=9825

[arnonmoscona]

I did. Debug was turned on and the line number in the exception stack trace matched exactly where you see time[i]. No question about that part...

[NinjaTrader_AdamP]

arnon,

Without code here I wouldn't really be able to investigate further. I am not aware of any reason this would occur just with that code sample. I will discuss with our tech lead.

If you want, you can submit the code to support at ninjatrader dot com with a reference to this thread. That way your code won't be public as we keep all that confidential.

[NinjaTrader_Brett]

MaximumBarsLookBack Set?

Do you have the data series?

Finally:

ITimeSeries time = Times[instrumentIndex];

Do you have this synced to the correct series in MTF with this sample?

http://www.ninjatrader.com/support/forum/showthread.php?t=3572

Thanks.