External calculation working on a backward looking sliding window

[Sivaji]

Hi,

 

I was working on an external calculation with a sliding window, however, as per the documentation, the window is forward-looking. I'm interested in a backward-looking window instead of a forward one, I tried to input '-' before the window size in the formula, but it threw an error message. This will help to calculate signal values up to the latest samples available.

 

Thanks,