search for: andvar3

...01/1999 2 c 1 2 10/02/2000 3 c 1 2 13/02/2000 4 n 2 1 11/02/2000 5 n 2 1 15/02/2000 6 n 2 1 23/02/2000 I want to select the observations whose difference of "var4" is less than 7 for the cases with the same values of var1,var2 andvar3. The obervations have the same var1, var2 and var3 are, part1 (obs2 and obs3) and part2 (obs4,obs5, and obs6). For obs2 and obs3, their date difference is less than 7, so we donot need to delete any of them. For obs4,obs5, and obs6,we can see that obs6 should be deleted becuase its date is ov...