CurrentBar in a for loop

[Stanfillirenfro]

Hi!
I really do not understand what is happening with the for loop here in Ninjatrader.
I am writing the code in protected override void OnBarUpdate().
I have done the following:

int Period = 15;

if(CurrentBar < 0)
return;

for(int i = 0; i < 5; i++)
{  double l_high = MAX(High, Period)[i];
   double l_low = MIN(Low, Period)[i];
}

On the output window, I have the error message: "Error on calling 'OnBarUpdate' method on bar 0:"
I have repeated the same code by replacing 5 by Currentbar and this time I could have the values of l_high and l_low.
I have then replaced 5 by Period and the error message was on bar 15.

What is the problem when I have the number 5 or 15?
What is the secret here in Ninjatrader to overcome this problem? This problem is receurrent for me and I really do not know what to do.
I would really appreciate any help.

[s.kinra]

Hello Stanfillirenfro,
You need below to fix it:

if (CurrentBar < 4)
return;

In for loop you're using MAX()[4] so you must skip that many bars. You must have these bars on chart so it can be processed, 4 in your case.
Hope it helps!

[Stanfillirenfro]

Hello S. Kinra and many thanks for your reply. The problem here is that when I increase the number to 500 for example,, I must set the condition to

if(CurrentBar < 500)
return.

In this case the calculation is very slow and I do not have my indicator on the chart.
Also, if I have something such as:

for(j= i; j <= i + 3; j++)
{
       Code
}

It is impossible here to have bars at position i+3

Is there any idea to solve this problem?

[NinjaTrader_ChrisL]

Hi Stanfillirenfro, thanks for posting.

If the CurrentBar property is > i+3 then it will not throw an error because there are enough bars on the chart to process the requested index. e.g. i = 1, x = 1+3 = 4 if CurrentBar > 4 then you will have no problem accessing Close[x], High[x], Open[x], etc. Now, if you are using a function like MAX and MIN, CurrentBar must be > the Period value. You can use Visual Studio debugging to break at the specific line causing the problem, which can help to identify what bar index is invalid:
https://ninjatrader.com/support/help..._debugging.htm

Kind regards,
-ChrisL

[s.kinra]

Hello Stanfillirenfro,
I don't have a work around in that case, this is the only working way I could figure out as of now. Hope someone from NT could help further. BTW do you really need that many bars back, maybe there is some other better way.

[Stanfillirenfro]

Many thanks ChrisLfor the explanation and also thanks to S.Kinra.
ChrisL please could you provide me a link to downoading visual studio? I have tried do download a visual studio but it seemed to be very big with some features not very usefull for me and I cancelled the installation.

S.Kinra with 500 I was testing to see the behaviour of the code with the increase of the number of bars since with CurrentBar it seemed to work except that the caalculation was indefinitely.and I could not have any indicator on the chart.

Best Regards

[NinjaTrader_ChrisL]

Hi Stanfillirenfro, thanks for your reply.

When you pick features for visual studio, just select the .NET desktop development with C#.

https://visualstudio.microsoft.com/

Kind regards,
-ChrisL

[Stanfillirenfro]

Many thanks ChrisL!