https://communities.sas.com/t5/SAS-Programming/Sum-in-between-every-second/m-p/486915#M287241 <P>Couple of ways of doing it, you could assign a group (rather than 1-sec mark, increase it to 1 se, 2 sec etc.) then means by the group variable.&nbsp; Or you could have a retained value in a datastep, e.g. (not tested, post test data in the form of a datastep in future):</P> <PRE>data want (drop=tot_trade); set have; by group; retain tot_trade; if first.group then tot_trade=0; if type="Trade" then tot_trade=sum(tot_trade,volume); if type="1-sec mark" and not first.group then do; volume=tot_trade; tot_trade=0; end; run;</PRE> Wed, 15 Aug 2018 07:47:51 GMT RW9 2018-08-15T07:47:51Z https://communities.sas.com/t5/SAS-Programming/Sum-in-between-every-second/m-p/486914#M287240 Thu, 04 Jun 2020 00:53:14 GMT https://communities.sas.com/t5/SAS-Programming/Sum-in-between-every-second/m-p/486914#M287240 trungcva112 2020-06-04T00:53:14Z https://communities.sas.com/t5/SAS-Programming/Sum-in-between-every-second/m-p/486915#M287241 <P>Couple of ways of doing it, you could assign a group (rather than 1-sec mark, increase it to 1 se, 2 sec etc.) then means by the group variable.&nbsp; Or you could have a retained value in a datastep, e.g. (not tested, post test data in the form of a datastep in future):</P> <PRE>data want (drop=tot_trade); set have; by group; retain tot_trade; if first.group then tot_trade=0; if type="Trade" then tot_trade=sum(tot_trade,volume); if type="1-sec mark" and not first.group then do; volume=tot_trade; tot_trade=0; end; run;</PRE> Wed, 15 Aug 2018 07:47:51 GMT https://communities.sas.com/t5/SAS-Programming/Sum-in-between-every-second/m-p/486915#M287241 RW9 2018-08-15T07:47:51Z