Creating a sum of group variable that is same for all observ. in group

[Xamius32]

    Lets say I have a value of 1 for each item in a group. Sometimes it adds to 13, somtimes to 7, etc. and then I want a  sum, which is the final value of each group. I know I can use last.variable for each group and then output to new dataset and then combine in sql easy enoug, but I want to avoid the extra step.

Basically:

Game	Value	Cum. Sum
A	1	1
A	1	2
A	1	3
A	1	4
A	1	5

I want the last cum. sum statement to be the last for each game (Game A would have 5 for each). Again, easy enough to do with last. and a join, but any easy way to simply do it all in one datastep?

[Reeza · Accepted solution]

Even if you do it in one datastep you're making more than one pass through the data.

If the one step is important, then look into a DOW loop.