topic Re: how to create and use macro variable within data step or any alternative? in SAS Programming

how to create and use macro variable within data step or any alternative?

Fri, 04 Oct 2013 18:44:16 GMT

Hello everyone,

I was wondering if there is a way to write dataset variable into a macro variable and use the macro variable within the same datastep.
I have tried different approaches to do the following; but have been running into call symput, excute so far. Thanks for any help that might help to solve the situation...

data atmp;
input anID surfix $;
datalines;
1 3_1
2 2_2
3 2_3
;
run;

data atmpdt;
input anID A_2_1 A_2_2 A_2_3 B_2_1 B_2_2 B_2_3;
datalines;
1 0.1 0.2 0.3 0.4 0.5 0.6
2 1.1 1.2 1.3 1.4 1.5 1.6
3 2.1 2.2 2.3 2.4 2.5 2.6
;
run;

%let prefixlist=A B;

data atmp2;
Merge atmp atmpdt; by anID;
/*Intention: read current row variable surfix into the macro variable asurfix*/
call symput('Asurfix',surfix);

nbvar = countw("&prefixlist"," ");
/*Intention: for each name in the macro variable "prefixlist"
create a dataset set variable initiliazed with the value in the var &aprefix._&Asurfix */
   do count = 1 to nbvar;
    call symput('aprefix',scan("&prefixlist",count," "));
&aprefix=&aprefix._&Asurfix;
   end;
run;

Re: how to create and use macro variable within data step or any alternative?

data_null__ — Fri, 04 Oct 2013 18:54:11 GMT

Why?

Look at SYMGET and RESOLVE functions.

Re: how to create and use macro variable within data step or any alternative?

PaigeMiller — Fri, 04 Oct 2013 18:58:00 GMT

To tell you the truth, I wouldn't do this with macros at all, I would use PROC TRANSPOSE.

proc transpose data=atmpdt out=a;
by anID;
run;

data aa;
merge a atmp;
by anID;
run;

Now you can assign A and B to the proper variables by matching text strings in data set AA, and throw out the observations in aa that don't match;

Re: how to create and use macro variable within data step or any alternative?

Patrick — Mon, 07 Oct 2013 01:52:08 GMT

SAS variables get created during the compilation phase of a data step. It is not possible to create additional SAS variables during execution phase.

SAS(R) 9.3 Language Reference: Concepts, Second Edition