Run time error with an intraday streaming strategy

Author: ss161

Creation Date: 12/4/2009 2:27 PM

Wealth Lab » Wealth-Lab Developer/Pro » Run time error with an intraday streaming strategy

ss161

12/4/2009 2:27 PM

I intermittently get the following error with an intraday streaming script:

I think this happens if / when my wireless internet briefly goes down and then immediately comes back up. Does that make sense? even so, any ideas why the internet going down would create that runtime error.

Thanks

Eugene

12/4/2009 2:49 PM

Here's what our Wiki knows about this error: (scroll down to) Object reference not set to an instance of an object. Something becomes null during this net hiccup...

ss161

12/5/2009 7:03 AM

Yes, i understand that part, and in general, can quickly debug those errors when they are caused by my code. In this case, the error seems to be generated somewhere in the code of SetBackgroundColor.

I use SetBackgroundColor in the script twice and in both instances call it with Bar (not Bar+1).

Eugene

12/5/2009 8:40 AM

Does it happen for this single strategy only? Could you also specify the symbol and time frame?

ss161

12/5/2009 8:59 AM

Hi, yes, for this strategy only. Symbol = FAZ, timeframe = 1 minute bars.

this is the only strategy that i am running with streaming mode on any intraday time frame. for most of my stratgies, I'm creating "ghost bars" outside of wealth-lab to run them in real-time. so while the answer above is yes for this strategy only. this is the only strategy that is running on a streaming basis.

Here is a code fragment:

CODE:
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Size:

Color:

Hi, yes, for this strategy only.  Symbol = FAZ, timeframe = 1 minute bars.

this is the only strategy that i am running with streaming mode on any intraday time frame.  for most of my stratgies, I'm creating "ghost bars" outside of wealth-lab to run them in real-time.  so while the answer above is yes for this strategy only.  this is the only strategy that is running on a streaming basis.

Here is a code fragment:
[CODE]
					for ( int Bar = StartBar; Bar < Bars.Count; Bar++ ) {
						if ( GetTime( Bar ) >= EOD ) {
							Signal = "E";
							if ( IsLastPositionActive ) {
								ExitAtMarket( Bar +1, Position.AllPositions, Signal);
							}
						} else {
							double stop =  ...;
							double pt = ...;
							if ( IsLastPositionActive ) {
								if ( Bar < Bars.Count -1 )
									DrawCircle( pane, 1, Bar+1, stop, Color.Red, Color.Red, WealthLab.LineStyle.Solid, 1, false );
								Signal = "Stopped";
								if ( !SellAtStop( Bar +1, Position.AllPositions, stop, Signal ) ) {
									if ( Bar < Bars.Count -1 )
										DrawCircle( pane, 1, Bar+1, pt, Color.Red, Color.Red, WealthLab.LineStyle.Solid, 1, false );									
									Signal = "ProfitTarget";
									SellAtLimit( Bar +1, Position.AllPositions, pt, Signal );
								}
							} 
							if ( ... )  ) {
  
								if ( IsLastPositionActive ) {

if ( Bar < Bars.Count -1 )
										DrawCircle( SPane, 8, Bar+1, Open[Bar+1], Color.Red, Color.Red, LineStyle.Solid, 2, true ); 
									ExitAtMarket( Bar +1, Position.AllPositions, Signal);
								} // then buy a new position
								Signal = "S";
								BuyAtMarket( Bar +1, Signal );
								LastPosition.Tag = Bars.Symbol;
								SetBackgroundColor( Bar, Color.LightGreen );
							}
							if ( ... )  ) { 
								Signal = "S";
								if ( IsLastPositionActive ) {
									ExitAtMarket( Bar +1, Position.AllPositions, Signal);
								}
								BuyAtMarket( Bar +1, Signal );
								SetBackgroundColor( Bar, Color.Salmon );
								if ( Bar < Bars.Count -1 )
									DrawCircle( SPane, 8, Bar+1, Open[Bar+1], Color.Green, Color.Green, LineStyle.Solid, 2, true );
							}
						}
					}[/CODE]

Cone

12/5/2009 5:13 PM

Try troubleshooting more by just removing the SetBackgroundColor statements for a day or two, or maybe better, just catch the error. If I remember to do it, I'll try running a simple script with SetBackgroundColor throughout the next trading day to see if that alone is the problem.

ss161

12/5/2009 11:05 PM

Sure, I can do that. Normally when I trap for an error, it is something I'm expecting so I just ignore it and continue executing my code (such as data not present for a symbol, so i skip the symbol). Is there generic code available that will dump the error once trapped via PrintDebug statements?