That will give a sample with exactly the same distribution (exactly 50 that are Type 1 etc). If you want to randomly sample, then you also need to know whether you are sampling from a population of size 1000 (without replacement) or from an infinite population. Briefly, these could be achieved by: Population size=1000: assign a random number to each observation, sort and take the first 100. Population size = infinite: generate a set of 100 random numbers between 1 and 1000. Merge this (by a variable containing observation number) with your data set of 1000 keeping those that were in your random number list (may include duplicates, because it is sampling with replacement). ... View more

Here is a macro that I use that also puts everything you might need into macro variables. (I have just improved it a bit by stealing Tom's idea of using countw). %MACRO makelist(base,list); * create a set of macro variables named base1, base2 ... with values from list + list returned as <base>list; %PUT &base &list; %GLOBAL n&base &base.list; %LET &base.list =&list; %LET n&base=%sysfunc(countw(&list)); %DO i=1 %TO &&n&base; %GLOBAL &&base&&n&base; %LET &&base&&n&base=%SCAN(&list,&&n&base); %END ; ; %PUT n&base = &&n&base; %DO i=1 %TO &&n&base;  %PUT &base&i &&&base&i; %END; %MEND; %makelist(test,D1 D2 D3); Then you can reference them with a loop in a macro eg. ... PROC MEANS; VAR &testlist; * D1 D2 D3; OUTPUT OUT=testmeans MEAN=%DO I=1 %TO &ntest; &&test&i..m %END; ; The output dataset contains means in the variables D1m D2m and D3m. ... View more

Another way ... data have;    input ID$   Weight;    uniqid = SUBSTR(ID,1,4);    cards; A101W1    140 lb A101W2    142 lb A102W1    145 lb A102W2    144 lb A103W1    139 lb A103W2    140 lb A104W1    144 lb A104W2    145 lb ;;;;    run; PROC SORT; BY uniqid weight; DATA have; SET have; BY uniqid; IF LAST.uniqid; DROP uniqid; PROC PRINT; RUN; ... View more

Use delimiter='|'; instead of dlm=... Your other problem may be due to a missing &  in front of filrf in (filename(filrf,&dir)); The fileref in a filename statement should be no more than 8 characters. I don't think it is the length of the file name (in windows) that is the issue. Hope this helps. ... View more