CODEWITHSUNDEEP
sassas-macrodo-loops
S420L
S420L

Reputation: 117

How to use call symput on a specific observation in SAS

I'm trying to convert a SAS dataset column to a list of macro variables but am unsure of how indexing works in this language. 

    DATA _Null_;
       do I = 1 to &num_or;
       set CondensedOverrides4 nobs = num_or;
       call symputx("Item" !! left(put(I,8.))
       ,"Rule", "G");
    end;
    run;

Right now this code creates a list of macro variables Item1,Item2,..ItemN etc. and assigns the entire column called "Rule" to each new variable. My goal is to put the first observation of "Rule" in Item1, the second observation in that column in Item2, etc.

I'm pretty new to SAS and understand you can't brute force logic in the same way as other languages but if there's a way to do this I would appreciate the guidance.

Upvotes: 1

Views: 2252

Answers (2)

Tom
Tom

Reputation: 51566

Much easier to create a series of macro variables using PROC SQL's INTO clause. You can save the number of items into a macro variable.

proc sql noprint;
  select rule into :Item1- 
  from CondensedOverrides4
  ;
%let num_or=&sqlobs;
quit;

If you want to use a data step there is no need for a DO loop. The data step iterates over the inputs automatically. Put the code to save the number of observations into a macro variable BEFORE the set statement in case the input dataset is empty.

data _null_;
  if eof then call symputx('num_or',_n_-1);
  set CondensedOverrides4 end=eof ;
  call symputx(cats('Item',_n_),rule,'g');
run;

Upvotes: 1

Reeza
Reeza

Reputation: 21264

SAS does not need loops to access each row, it does it automatically. So your code is really close. Instead of I, use the automatic variable _n_ which can function as a row counter though it's actually a step counter. 

DATA _Null_;
   set CondensedOverrides4;
   call symputx("Item" || put(_n_,8. -l) , Rule, "G");
run;

To be honest though, if you're new to SAS using macro variables to start isn't recommended, there are usually multiple ways to avoid it anyways and I only use it if there's no other choice. It's incredibly powerful, but easy to get wrong and harder to debug.

EDIT: I modified the code to remove the LEFT() function since you can use the -l option on the PUT statement to left align the results directly.

EDIT2: Removing the quotes around RULE since I suspect it's a variable you want to store the value of, not the text string 'RULE'. If you want the macro variables to resolve to a string you would add back the quotes but that seems incorrect based on your question.

Upvotes: 0

Related Questions