Macro variable creation based on date value in SAS

Question

I have a list of company IDs and Dates and I want to run a macro on this list in such a way that for each date all the company IDs need to be considered as my macro filter.

For example, my list is -

 DATA comp_date_list;
   INPUT compno sdate;
   DATALINES;
    12490 20090120
    87432 20090120
    24643 20090120
    87432 20090119
    12490 20090105
    24643 20090105
    ;
    proc print data=comp_date_list;
    run;

Now, I have a macro that is as follows -

%macro1(compno=,sdate=,threshold=,fdate=,edate=)

Now The macro has to run for every comp-date combination in my list. But since this is to run on a very large dataset, running it n times will take a long time. So to reduce the runtime, I plan to make a list of compnos for a given date and alter my macro to produce the results for a date.

Now my question is how to create a macro variable that has all the compnos for a given date and which alters as date changes? am new to macro writing and SAS. So please excuse my ignorance. Thanks!

Answer 1

A call execute statement in a datastep can run selective code (in this case, your macro) after the datastep in which it was called. For example, the following should work for you:-

proc sort data = comp_date_list;
  by sdate compno;
data _null_;
  set comp_date_list;
  by sdate;

  attrib all_comps_on_date length=$1000 label="All_comps_on_date: '|' separated company numbers for date";
  retain all_comps_on_date "";

  if first.sdate then all_comps_on_date = '';
  all_comps_on_date = catx('|', all_comps_on_date, compno);
  if last.sdate then call execute('%macro1(compno='||strip(all_comps_on_date)||',sdate=,threshold=,fdate=,edate=)');
run;

A note of caution though; call execute can play havoc with macros that themselves create macro variables (especially if they are using call execute statements!)

I can only echo @ChrisJ and add that while SAS macros can be useful, maintaining and debugging them is a pain and I only use them as a last resort. Not much help of course with legacy code!