topic Combining multiple datasets using a loop in Statistical Procedures

Combining multiple datasets using a loop

ammarhm — Fri, 26 Jun 2015 01:15:28 GMT

A quick question.

I have several datasets (HR1, HR2, HR3,.....HR 20)

I need to combine a number of these tables using (data..set) according to certain criteria, since this is a repetitive task I chose to build a macro like this

%macro repeat_set(n=);

%do var=1 %to &n;

Data j;

if &var=1 then do;

set HR&var;

end;

else if &var gt 1 then do;

set j HR&var;

end;

run;

%end;

%mend;

The reason why I am doing this is that the new dataset 'J' dose not exist from the beginning, so while looping, the idea is when the code takes the first HR set (HR1) it will create 'j' using the following:

data j;

set HR1;

run;

and for the consequent sets, like HR2 , it will do

data j;

set j HR2;

run;

and so on

So when I do a

%repeat_set(n=1);

the code executes correctly

BUT, when I do anything larger than 1, ex

%repeat_set(n=5);

The code combines only tables HR2-HR5. It seems as if HR1 contribution to the new set 'j' is "deleted" during the process.

Any suggestions?

Best regards

Re: Combining multiple datasets using a loop

Tom — Fri, 26 Jun 2015 01:18:54 GMT

Why not just combine them all in one step?

data want ;

set hr1-hr20;

run;

Re: Combining multiple datasets using a loop

ammarhm — Fri, 26 Jun 2015 01:27:42 GMT

The reason is that it is a part of a larger code that I need to actively decide the number of tables to include, and I need to programatically be able to change one value in the code rather than changing it at several places

Anyhow, found the problem myself (missing %), but your code works too of course

Kind regards

Re: Combining multiple datasets using a loop

Tom — Fri, 26 Jun 2015 01:55:07 GMT

How are you "actively" deciding how many tables to include? Do you mean the parameter N to the macro?

%let n=5 ;

data J;

set hr1-hr&n;

run;