Chart Error

[SymeBB]

Hi,

I have a strage problem.

If I load my indicator on chart when Market Replay is playing, my 8 Range Chart is gone and the indicator deactivated.

Here are some attachments (and the indicator):





aTrend2.zip

Is this a NT bug?

Can you help me with this problem?

Thank you.

[NinjaTrader_JoshP]

Please check your Log tab for runtime errors. This looks to be a case of erroneous indicator coding which ran into an issue and could not continue running.

[SymeBB]

This is the error:

Error on calling 'OnBarUpdate' method for indicator 'aTrendEnter' on bar 56: Object reference not set to an instance of an object.

I have another indicators with the same code (and no errors), but this one has the following condition:

if (Close[i] > Open[i-2] && High[i-2] < Close[i-8])

If this condition is part of any indicators I have, I get the same error.

What is wrong with this condition?

[NinjaTrader_JoshP]

It is not necessarily the condition at fault, but somewhere else in your code. Please use try-catch blocks throughout your code to isolate out where exactly in your code it is running into the issues on bar 56.

For more information on try-catch blocks please see here: http://www.ninjatrader.com/support/f...ead.php?t=9825

[SymeBB]

The same problem

Here is what I have in output window after try-catch:

3/23/2011 8:36:54 AM System.NullReferenceException: Object reference not set to an instance of an object.
at NinjaTrader.Data.MemBars.GetOpen(Int32 index)
at NinjaTrader.Data.Bars.GetOpen(Int32 index)
at NinjaTrader.Indicator.DataSeriesHelper.get_Item(In t32 barsAgo)
at NinjaTrader.Indicator.aTrend2.OnBarUpdate()

This is my try-catch code:

for (int i = 0, a = 1, b = 1, c = 2, d = 3; i < Period; i++, a++, b++, c++, d++)
				
				
				
        	{
				try {
					if (Close[i] > Open[i-2] && High[i-2] < Close[i-8])
						var2 = var2 + 1;
				}
				
				catch (Exception e)
						
			
			{
				/* With our caught exception we are able to generate log entries that go to the Control Center logs and also print more detailed information
				about the error to the Output Window. */
				
				// Submits an entry into the Control Center logs to inform the user of an error
				Log("SampleTryCatch Error: Please check your indicator for errors.", LogLevel.Error);
				
				// Prints the caught exception in the Output Window
				Print(Time[0] + " " + e.ToString());
			}
					
			
			}
			
			Short.Set(var2);

Is there something wrong with the code I wrote?

[SymeBB]

Debbuging in Visual Studio shows no error.

[NinjaTrader_JoshP]

SymeBB,

Please try-catch the whole code everywhere. Leave nothing in OnBarUpdate() outside of a try-catch block. Using different print statements from the try-catch block will allow you to identify which one exactly is printing.

But actually if the output you are saying is coming from the try-catch block you have already then that is fine. What you would need to do next is to isolate the individual component from within that block that is causing the issue with additional try-catchs.

[SymeBB]

But how can I go deeper in that code?

I have isolated this condition:

if (Close[i] > Open[i-2] && High[i-2] < Close[i-8])

Is there some way I can go deeper in?

[NinjaTrader_JoshP]

Break your if-statement into multiple parts and try-catch each section. Then debug it with Print() statements.

By looking at your code it is highly possible that you are just passing in invalid [] index values.

i=0 means you are trying to do Open[-2]. You cannot have negative index values.

[SymeBB]

That [i-2] is resolved as follows:

if(CurrentBar < Period + 9)
return;

It is not the case to have invalid index values.

[NinjaTrader_JoshP]

SymeBB,

Then all I can advise is to continue debugging and break down the bricks even further.