Set analysis operations

[Franco2]

Hi!

I have a dataset that looks like this:

Sale	Month	Cost	Benefit
1	201901	10	10
2	201901	20	20
3	201901	10	10
4	201901	20	40
5	201901	30	20
6	201902	40	20
7	201902	10	10
8	201903	20	30
9	201903	50	40
10	201903	10	10

And what I'm trying to get is a chart where I can see the evolution of the Benefit in a Month minus the cost of the previous month.

What I'm looking for is in this table:

Month	Cost	Benefit	Gain
201901	90	100	100
201902	50	30	-60
201903	60	80	30

If anyone knows how to put in a chart the Gain per month I'll be really healpful.

[stevejoyce · Accepted solution]

sum(Cost)

sum(Benefit)

sum(Benefit) - alt(above(sum(Cost)),0)

[Franco2]

Thank you soo much. It helped me. 

Only one thing. If I'd like to discount the cost not from the previous month but from two months ago, how would it be?

sum(Benefit) - alt(above(sum(Cost)),1) 

something like that