Accessing plots

[andersonbd]

Hi folks-

I have an indicator that plots the percent change in price from current day open on three instruments -- found the code on YouTube and modified it for my purposes. These instruments are each added to the indicator via a one tick series. The calculated values plot as desired, as well as a summation of the calculated plots.

However, when I try to access these plots through another indicator (like trying to take an HMA of the one of the plots), either through an indicator or a strategy, I get the following errors:

• Indicator 'PCsum2' (the name of the custom indicator): Error on calling 'OnBar'Update' method on bar 20: Index was outside the bounds of the array.
• Indicator 'HMA' (trying to take an HMA of one of the plots): Error on calling 'OnBar'Update' method on bar 1: You are accessing an index with a value that is invalid since it is out-of-range.
• Indicator 'WMA' (not sure why this shows up, I'm using an HMA...): Error on calling 'OnBar'Update' method on bar 0: You are accessing an index with a value that is invalid since it is out-of-range.

When I try to do this inside a strategy, I get similar error messages but sometimes with really high bar numbers in the thousands.

Attached is the indicator code. Can anyone point me in the right direction?

Many thanks!

[NinjaTrader_BrandonH]

Hello andersonbd,

Thanks for your post.

These error messages indicate that you are trying to access a BarsAgo value that is not valid. A more simple example using one series would be on bar 5 you check for 6 BarsAgo. There are not yet 6 bars so the CurrentBar minus 6 would be a negative number or a non-existent bar.

A CurrentBars check could be used in your indicator's logic to ensure that a certain number of bars have processed before the indicator begins calculation.

In the script you shared I see you have a CurrentBars check for the added series but not for the primary series the script is running on. A CurrentBars check would need to be added to the script to check if the primary series has enough bars.

See the help guide documentation below for more information.

CurrentBar - https://ninjatrader.com/support/help...currentbar.htm
CurrentBars - https://ninjatrader.com/support/help...urrentbars.htm
Make sure you have enough bars - https://ninjatrader.com/support/help...nough_bars.htm

Indexing errors can also occur when using an invalid index with arrays or collections. Below is a forum thread with a publicly available link to 3rd party educational site on arrays and index out of range errors.

https://forum.ninjatrader.com/forum/...1050092

[andersonbd]

Got it, thanks Brandon!