Variable

[honeyblue]

I have 25 observations i want to assign 1 to a variable for 1 - 12 observations and assign 2 to the same variable for 13-25 observations

[ballardw · Accepted solution]

by order or randomly?

If you mean by order, the first 12 records are to be one then:

data want;
   set have;
   if _n_ le 12 then variable=1;
   else variable=2;
run;

_n_ is a SAS automatic variable that counts iterations of a data step. In a simple use like this it is basically the row number.