Resetting a summed array

AFL Programming
1

I have some variable for which I’m taking a running sum with Cum().

The sum starts from the first bar, but it needs to"reset" back to zero after certain events, like a Sell or Cover, and then start the sum again until the next event.

Is this possible to do? I’m on Amibroker 5.4

2

Version 5.40 is not supported.

Newest versions (6.06 or higher) have SumSince function that does what you need efficiently.