How to use loop with a macro in SAS

Question

I have a question about how to use loop in % macro. I've written a sas macro that looks like that:

%macro SortDaysRolling(outdat,var);
proc sort data =  &outdat. (keep=ACM_ACCT_NUM DIM_DATE_ID &var.); by ACM_ACCT_NUM DIM_DATE_ID; run;
%mend SortDaysRolling;

I need to apply this function to a number of files, ie:

%SortDaysRolling(days_rolling_1_1_1_4,count_times_days_1_4);
%SortDaysRolling(days_rolling_1_1_5_9,count_times_days_5_9);
%SortDaysRolling(days_rolling_1_1_10_14,count_times_days_10_14);
%SortDaysRolling(days_rolling_1_1_15_19,count_times_days_15_19);
%SortDaysRolling(days_rolling_1_1_20_24,count_times_days_20_24);
%SortDaysRolling(days_rolling_1_1_25_29,count_times_days_25_29);
%SortDaysRolling(days_rolling_1_1_30_44,count_times_days_30_44);
%SortDaysRolling(days_rolling_1_1_45_59,count_times_days_45_59);
%SortDaysRolling(days_rolling_1_1_60_89,count_times_days_60_89);
%SortDaysRolling(days_rolling_1_1_90,count_times_days_90);

and then

%SortDaysRolling(days_rolling_1_2_1_4,count_times_days_1_4);
%SortDaysRolling(days_rolling_1_2_5_9,count_times_days_5_9);
%SortDaysRolling(days_rolling_1_2_10_14,count_times_days_10_14);
%SortDaysRolling(days_rolling_1_2_15_19,count_times_days_15_19);
%SortDaysRolling(days_rolling_1_2_20_24,count_times_days_20_24);
%SortDaysRolling(days_rolling_1_2_25_29,count_times_days_25_29);
%SortDaysRolling(days_rolling_1_2_30_44,count_times_days_30_44);
%SortDaysRolling(days_rolling_1_2_45_59,count_times_days_45_59);
%SortDaysRolling(days_rolling_1_2_60_89,count_times_days_60_89);
%SortDaysRolling(days_rolling_1_2_90,count_times_days_90);

So the middle index changes. Since i = 1, ..., 35, I don't want to copy-paste all those lines 35 times. Is there any way to do the loop?

Thank you very much.

Answer 1

You need to determine your sequence abstraction. Then construct the sort macro invocations based on that.

%macro SortDaysRolling(out, var);
  %put NOTE: &SYSMACRONAME: &=out &=var;
%mend;

%macro sort_loop (I_FROM=1, I_TO=&I_FROM, J_FROM=1, J_TO=&J_FROM);

  %local I J;

  %do I = &I_FROM %to &I_TO;
  %do J = &J_FROM %to &J_TO;

    %SortDaysRolling(days_rolling_&I._&J._1_4,count_times_days_1_4);
    %SortDaysRolling(days_rolling_&I._&J._5_9,count_times_days_5_9);
    %SortDaysRolling(days_rolling_&I._&J._10_14,count_times_days_10_14);
    %SortDaysRolling(days_rolling_&I._&J._15_19,count_times_days_15_19);
    %SortDaysRolling(days_rolling_&I._&J._20_24,count_times_days_20_24);
    %SortDaysRolling(days_rolling_&I._&J._25_29,count_times_days_25_29);
    %SortDaysRolling(days_rolling_&I._&J._30_44,count_times_days_30_44);
    %SortDaysRolling(days_rolling_&I._&J._45_59,count_times_days_45_59);
    %SortDaysRolling(days_rolling_&I._&J._60_89,count_times_days_60_89);
    %SortDaysRolling(days_rolling_&I._&J._90,count_times_days_90);

  %end;
  %end;

%mend;

%sort_loop (J_TO=35);

The 10 count_times_days variables could also be abstracted, or constructed from generation rules.

Answer 2

Generating the numbers in-macro would shorten the code whilst making it a bit cryptic.

The below macro generates the table name and varname, and checks if the table exists before executing the %sortdaysrolling macro block.

%macro SortDaysRolling(outdat,var);
proc sort data =  &outdat. (keep=ACM_ACCT_NUM DIM_DATE_ID &var.); by ACM_ACCT_NUM DIM_DATE_ID; run;
%mend SortDaysRolling;

options mprint mlogic;

%macro sortvarloop;

%do i = 1 %to 2;

    %let j = 1;
    %do %until (&j = 90);

    %if &j = 1 %then %let k = 4;
    %else %let k = %sysevalf(&j + 4)

    %if &j = 90 %then %let tabsuff = %str( );
    %else %let tabsuff = _&k;

        %if %sysfunc(exist(days_rolling_1_&i._&j.&tabsuff.)) %then %do;
        %sortdaysrolling(days_rolling_1_&i._&j.&tabsuff.,count_times_days_&j.&tabsuff.);
        %end;

    %let j = %sysevalf(&j + 5);
    %end;

%end;

%mend sortvarloop; %sortvarloop;

But if you really want to use a macro block, you should think a little ahead and adopt some naming convention for easy and less-harsh-on-memory execution.