[rules-users] fusion aggregate functions

Hi guys, I have found in the documentation examples in sliding windows part, the average aggregate , I need other aggregates like max. min , standard deviation ... is there any of those already buitin ? I have searching the docus. , but havn't found much dealing with the built in aggregate functions. Also if I want to implement one of them using normal rules , Is it true that it will not be as sufficient ? Thanks, k-