topic Re: Macro with a global variable in SAS Programming

Macro with a global variable

willow2010 — Tue, 13 Sep 2011 07:17:53 GMT

I have the following piece of code. It works.

DATA T_GROUP1

T_GROUP2

T_GROUP3

;

SET T_GROUP ;

IF GROUP_COUNT = 1 THEN DO ;

CURRENT = INT(TIME()*100);

RANDOM = INT(RANUNI(CURRENT)*100000);

OUTPUT T_GROUP1;

END ;

ELSE

IF GROUP_COUNT = 2 THEN DO ;

CURRENT = INT(TIME()*100);

RANDOM = INT(RANUNI(CURRENT)*100000);

OUTPUT T_GROUP2;

END ;

ELSE

IF GROUP_COUNT = 3 THEN DO ;

CURRENT = INT(TIME()*100);

RANDOM = INT(RANUNI(CURRENT)*100000);

OUTPUT T_GROUP3;

END ;

RETURN ;

PROC SORT DATA=T_GROUP1 ; BY RANDOM ;

PROC SORT DATA=T_GROUP2 ; BY RANDOM ;

PROC SORT DATA=T_GROUP3 ; BY RANDOM ;

T_GROUP has a variable called MAXNUM that captured the maximum number of GROUP_COUNT, in this case, MAXNUM=3.

Suppose I would like to make the above ‘repeatable’ code into a DO LOOP, I think I might need something like DO I = 1 TO 3 THEN DO;

Suppose my input data are not always the same, sometimes could have more and sometimes could have less number of GROUP_COUNT and I would like to maintain the above code structure to reflect that. Looks like I really would like to make MAXNUM into some kind of Global variables and as well a macro to call the whole thing. How can I do it??

Re: Macro with a global variable

dhana — Tue, 13 Sep 2011 11:37:09 GMT

Check this solution

%MACRO TGRUP;

DATA _NULL_;

SET T_GROUP;

CALL SYMPUT('MAXN', MAXNUM);

RUN;

%DO I=1 %TO &MAXN;

DATA T_GROUP&I;

SET T_GROUP;

IF GROUP_COUNT= &I THEN DO;

CURRENT = INT(TIME() *100);

RANDOM = INT(RANUNI(CURRENT)*100000);

OUTPUT T_GROUP&I;

END;

RUN;

PROC SORT DATA = T_GROUP&I; BY RANDOM;

%END;

%MEND TGRUP;

%TGRUP;

Hope this helps....!

Thanks

Dhanasekaran R

Re: Macro with a global variable

BobD — Tue, 13 Sep 2011 15:05:41 GMT

Here's a slight improvement to the previous (and well done) solution. It's more efficient to read the starting table once to create all the requested datasets.

%MACRO TGRUP;

DATA _NULL_;
     SET T_GROUP;
     CALL SYMPUT('MAXN', MAXNUM);
     STOP;
RUN;

DATA

%DO I=1 %TO &MAXN;
T_GROUP&I
%end;

;
SET T_GROUP;

%DO I=1 %TO &MAXN;
   IF GROUP_COUNT= &I THEN DO;
      CURRENT = INT(TIME() *100);
      RANDOM = INT(RANUNI(CURRENT)*100000);
      OUTPUT T_GROUP&I;
      END;
%end;

RUN;

%DO I=1 %TO &MAXN;
PROC SORT DATA = T_GROUP&I; BY RANDOM;
RUN;
%end;

%MEND TGRUP;

%TGRUP;

Re: Macro with a global variable

willow2010 — Wed, 14 Sep 2011 02:59:15 GMT

Thank you Dhanasekaran R and BobD very much!

Your thoughtful hard work and expertise are deeply appreciated!

Now not only this piece of code works, I managed to ‘mimic’ this Macro methodology / syntax to apply it to other part of my code before I set up some more SQL... Now I basically have attained the kind of result I expected to see; probably I would still like to do a bit more of testing before I really say ‘it’s finished!’

Thanks, buddy!