Horizontal Line not updating

[TheTradingMantis]

I have a very simple indicator that draws a horizontal line at the current price.

public class PriceLine : Indicator
{
	protected override void OnStateChange()
	{
		if (State == State.SetDefaults)
		{
			Description = @"Plots a horizontal line at current price.";
			Name = "PriceLine";
			Calculate	= Calculate.OnEachTick;
			IsOverlay	= true;
			DisplayInDataBox = false;
			DrawOnPricePanel	= true;
			DrawHorizontalGridLines = false;
			DrawVerticalGridLines = false;
			PaintPriceMarkers = false;
			ScaleJustification = NinjaTrader.Gui.Chart.ScaleJustification.Right;
			IsSuspendedWhileInactive = false;
		}
	}
	protected override void OnBarUpdate()
	{
			Draw.HorizontalLine(this,"CurrentPrice", true, Close[0], Brushes.DarkGray, DashStyleHelper.DashDotDot, 1);
	}
}

I have a chart with 3 data series in 3 different panels. I add the indicator 3 times, once for each data series

After a while, one or more horizontal lines stop updating (see the dotted line in the middle panel on the first image).

When I open the indicators panel, it appears the horizontal line that is not updating is not longer connected to a data series (see second image).

If I reload Ninjascript, everything is fine again.

Any idea what the problem is?

[NinjaTrader_AlanP]

Hello gregschr,

I am unable to reproduce with the information you provided.

Are you minimizing the chart at any point?

What session template do you have applied to your GC?

Are you changing the primary instrument at any point?

Are you changing time intervals?

I look forward to your reply.

[TheTradingMantis]

Hi Alan,

The problem is rather random, so I am not surprised you have not been able to reproduce it. I also observed this on the ES data series after I submitted the post. I do not recall if I have ever seen this on the primary series.

In answer to your questions:
1) I have not minimized the chart at any time.
2) All three data series are set to "Use instrument settings"
3) I have not changed the primary series.
4) I have not changed any intervals.

I've attached a screen shot of the GC data series properties.

Thanks,
Greg

[TheTradingMantis]

I was doing some testing using Playback Connection and found another way to reproduce this error easily.

Whenever I use GoTo to jump ahead to a later date/time, the PriceLine indicator almost always disconnects from the Data Series.

Also, if you run the connection at 10X during a period of higher liquidity (e.g. US morning), it generally does not take long for the PriceLine to disconnect from the Data Series.

[TheTradingMantis]

Not sure why I did not check the log earlier, but here is the error that is generated when the data series disconnects from the indicator.

Indicator 'PriceLine': Error on calling 'OnBarUpdate' method on bar 6185: You are accessing an index with a value that is invalid since it is out-of-range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart.

[NinjaTrader_AlanP]

Hello gregschr,

I was able to replicate on replay and have submitted a bug report.

Thank you for your report.

[NinjaTrader_AlanP]

Hello gregschr,

I wanted to update you that it looks like the issue with the horizontal line detaching is slated to be resolved in the next issue of NinjaTrader, V8R9 which you can confirm upon its release by searching 11918 in the release notes. This of course could change but as of now that is what it looks like.

Thank you.

[TheTradingMantis]

Thanks for the update Alan.

A workaround until the next release is to wrap the Draw.HorizontalLine statement in a Try/Catch block. This seems to address the issue as I have not had any problems since doing so.