topic Re: how to use &&var&i in if condition in SAS Programming

how to use &&var&i in if condition

Chaichai — Wed, 30 May 2018 04:52:22 GMT

/* Create macro variables to store restrictions */

PROC SQL NOPRINT;

SELECT RESTRICTIONS

INTO :RESTRI1 - :RESTRI35 FROM SASDATA.restriction;

QUIT;

%PUT &RESTRI2;

/*the resolved value is: */

gender = 'M' and state = 'CA'

/*I want to create a data set sasdata.newlist&i when the ith restriction

is &&restri&i (eg: gender = 'M' and state = 'CA')*.

***While the sasdata.newlist2 contains all data in sasdata.oldlist, the if condition doesn't work. Anybody can help me to solve this problem?*/***

%Macro testing(I);

data sasdata.newlist&i;

set sasdata.oldlist;

%if &&restri&i %then; /*I only want the observations which meet the restriction &&restri&I* in this new created dataset/

run;

%mend testing;

%testing(2)

Re: how to use &&var&i in if condition

ChrisNZ — Wed, 30 May 2018 05:55:29 GMT

Like this?

%let restri2=sex='F';
%macro testing(I);
  data T;
    set SASHELP.CLASS;
    where &&restri&i ; 
  run;
%mend testing;
%testing(2)

NOTE: There were 9 observations read from the data set SASHELP.CLASS.
WHERE sex='F';

Re: how to use &&var&i in if condition

Kurt_Bremser — Wed, 30 May 2018 07:49:43 GMT

Or this:

%Macro testing(I);
     data sasdata.newlist&i;
     set sasdata.oldlist;
     if &&restri&i; /* simple subsetting if in data step, and condition replaced */
     run;
%mend testing;

Never try to handle actual data with macro statements (that's what you did with using the macro %if instead of the data step if).

The subsetting if may be needed in some instances; in this simple example, the where condition as suggested by @ChrisNZ will be sufficient and perform better.

Re: how to use &&var&i in if condition

Chaichai — Wed, 30 May 2018 22:27:27 GMT

Thanks, it works

Re: how to use &&var&i in if condition

Chaichai — Thu, 31 May 2018 03:49:44 GMT

While it's hard to tell when to use macro statement, when not.

for example: Do I need to put % in the if -then-else statement and do while statement? By the way, can I use "Do i = 1 to n while (condition)" statement here like this?

%MACRO FUNDSOURCE(I);
DATA SASDATA.STUDENT&I;
SET SASDATA.STUDENTLIST
DO M = 1 TO 310 WHILE(&&BUDG&I > 0); /*loop through all observations_ALL STUDENTS*/
IF &&BUDG&I LE 3000- FA_TOT1 THEN do;
DISBURSE = &&BUDG&I;
FA_TOT1+DISBURE;
&&BUDG&I - DISBURSE;
end;
ELSE IF &&BUDG&I GT (3000- FA_TOT1) THEN DO;
DISBURSE = 3000-FA_TOT1;
FA_TOT1+DISBURSE;
&&BUDG&I - DISBURSE;
END;
END;

IF _n_ > M THEN DELETE; /*if budget are all gone, delete other observations, keep observations only for the student who get funds*/
RUN;
%MEND FUNDSOURCE;