How to retain sum of previous row to use in current row

[huffa9299]

Hello,

Is there a way to retain the sum of one row and use that sum as the starting point for a second row?

for example-

Have:

Month	Start	New	Cancelled	End
Jan	10	2	-1
Feb		1	-3
March		4	0

Want:

Month	Start	New	Cancelled	End
Jan	10	2	-1	11
Feb	11	1	-3	9
March	9	4	0	13

Thank you!

[novinosrin · Accepted solution]

data have;
infile cards truncover;
input Month $	Start	New	Cancelled	End;
cards;
Jan	10	2	-1	 
Feb	 .	1	-3	 
March	. 	4	0
;

data want(drop=_end);
set have;
retain _end;
if _n_=1 then do; _end=sum(of start--cancelled);end=_end;end;
else do; start=_end;_end=sum(of start--cancelled);end=_end;end;
run;

[huffa9299]

worked perfectly! thank you for your help