topic Re: Trying to use SAS macro to create variable name in SAS Programming

Trying to use SAS macro to create variable name

carl01 — Sat, 29 Feb 2020 21:47:48 GMT

HI, I'm trying to use sas macro to create a dynamic variable name. Below is the snippet of my code:

%macro test123;
%do i= 0 %to 76;
if ((Fdevyr - Flye) * 4 + int((Fdevm - 1) / 3) - int((FM - 1) / 3)) = &i. then do;
if component = 'Counts' then Amount_0&i. = count;
end;
%end;
%mend test123;

this code creates a new Variable - Amount_00, Amount_01..upto Amount_76.and so on but instead I would like to create the variable names as Amount_01,Amount_02...Amount_77 using the above code.

I have tried using Amount_0&i+1 but I think that's not a valid way of using it.

I have tried %let j= &i.+1 inside my Do Loop but I think we cannot have another macro variable inside a macro.

I'm a beginner to SAS and any suggestions are much appreciated. Thank you

Re: Trying to use SAS macro to create variable name

novinosrin — Sat, 29 Feb 2020 22:24:32 GMT

I am failing to understand why you would want to loop from 0 to 76 when you apparently want var names suffixes from 1 to 77?

If I were to assume you want a leading zero for values that are single digit numbers, you could address that with a Z format to standardize that, i.e

/*First Check the values in the log to see if this is what you are after*/
%macro test123;
%do i= 1 %to 77;
%put %sysfunc(putn(&i,z2.));
%end;
%mend test123;

/*If the above is what are after then plug that*/

%macro test123;
%do i= 1 %to 77;
if ((Fdevyr - Flye) * 4 + int((Fdevm - 1) / 3) - int((FM - 1) / 3)) = &i. then do;
if component = 'Counts' then Amount_%sysfunc(putn(&i,z2.)) = count;
end;
%end;
%mend test123;

Re: Trying to use SAS macro to create variable name

Tom — Sat, 29 Feb 2020 22:11:46 GMT

How are you using that code that macro generates?

Why is the macro any better than just defining an ARRAY in the data step that is using that code?

Re: Trying to use SAS macro to create variable name

Patrick — Sat, 29 Feb 2020 22:12:35 GMT

Something like below should do what you want.

%macro test123;
  %do i= 1 %to 77;
    %if &i>1 %then else;
    if ((Fdevyr - Flye) * 4 + int((Fdevm - 1) / 3) - int((FM - 1) / 3)) = %eval(&i.-1) then
      do;
        if component = 'Counts' then
          Amount_0&i. = count;
      end;
  %end;
%mend test123;

Re: Trying to use SAS macro to create variable name

carl01 — Sat, 29 Feb 2020 22:20:52 GMT

Thanks Patrick

Re: Trying to use SAS macro to create variable name

Patrick — Sat, 29 Feb 2020 22:31:43 GMT

@carl01 wrote:

Thanks Patrick

ehhmm... .then may-be you should mark my answer as the solution....
From a coding perspective using a SAS datastep array instead of macro coding is "better".

Re: Trying to use SAS macro to create variable name

RichardDeVen — Thu, 05 Mar 2020 18:03:40 GMT

I'm a beginner to SAS

That is a good justification for not jumping into Macro. There is huge utility in the DATA Step language without a need for any macro.

Far less confusing would be to use a variable based array to create the variable names amount_00-amount_76. Your complex formula would compute the index for assignment.

data want;

  array amts amount00-amount76;

  index = ((Fdevyr - Flye) * 4 + int((Fdevm - 1) / 3) - int((FM - 1) / 3));
  if component = 'Counts' then amts(index) = count;

run;