- data m1;
- set sample;
- a=compress(code,,"d");
- b=compress(code,,'a');
- c=cats(b,a);
- date1=input(date,mmddyy10.) ;
- date2=lag(date1);
- run;
- data m2;
- set m1 ;
- by c;
- if c ne lag(c) then date3=date2;
- date3+0;
- if date1<date3 then delete;
- drop a b c date1 date2 date3;
- run;