error when using swing indicator in a strategy

[Playdc]

Here is the code that is used in the strategy

int BarsAgo = Swing(SwingStrength).SwingHighBar(0, 1, Bars.BarsSinceNewTradingDay);
if(BarsAgo < 0 || CurrentBar <= BarsAgo) return;
double swingHigh = Swing(SwingStrength).SwingHigh[BarsAgo];

The strategy works properly for some date ranges. For some date ranges, It would pop up an error as follows

2024/10/24 15:16:26,Default,Strategy 'SwingTest': Error on calling 'OnBarUpdate' method on bar 34790: 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.,

My question is how to trap this error so the strategy could continue to run.

[NinjaTrader_ChelseaB]

Hello Playdc,

Any index used must be less than the size of the collection. For Series objects, the barsAgo index must be less than or equal to CurrentBar (and equal to or greater than 0).

https://ninjatrader.com/support/forum/forum/ninjatrader-8/indicator-development/1046200-indicator-that-calculate-in-different-chartime?p=1048513#post1048513

Your current code requires BarsAgo to be equal or greater than CurrentBar not less than CurrentBar.

if(BarsAgo < 0 || CurrentBar <= BarsAgo) return;

This states to return if CurrentBar is less than or equal to BarsAgo. However, CurrentBar must be greater or equal to the BarsAgo index.

[Playdc]

Hi Chelsea,

Sorry, I am a little bit confused. I think the statement in my code as follows to catch the cases when BarAgos>=CurrentBar then it would just return and don't do any calculations.

if (BarsAgo < 0 || CurrentBar <= BarsAgo) return;

[NinjaTrader_ChelseaB]

Hello Playdc,

My apologies, I think you've got that correct and I was not reading that correctly.

Add prints to see what is causing the issue.

int BarsAgo = Swing(SwingStrength).SwingHighBar(0, 1, Bars.BarsSinceNewTradingDay);
if(BarsAgo < 0 || CurrentBar <= BarsAgo) return;
Print(string.Format("{0} | CurrentBar: {1}, BarsAgo: {2}", Time[0], CurrentBar, BarsAgo));
double swingHigh = Swing(SwingStrength).SwingHigh[BarsAgo];

[Playdc]

Hi, I followed your instructions to add the print statements for debugging. However, I didn't get any output from ninjascript output windows. What I got is still the error message in log tab as follows
2024/11/12 15:16:26,Default,Strategy 'SwingTest': Error on calling 'OnBarUpdate' method on bar 34790: 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_ChelseaB]

Hello Playdc,

Does the print output show in the output window before the error appears?

If not, move the print higher in the code.