topic Re: Macro if then do question in SAS Programming

Macro if then do question

IgawaKei29 — Mon, 23 Mar 2020 14:06:06 GMT

So macro programming has always been a weakness for me, but I am trying to do something fairly simple to give it a go for date automation.

So what I want to happen is based on the run date, it will create the Quartercal for me based on my logic below. So I am missing something when running this macro but I am not sure what it is. I haven't done many of these if, then, do, else if, types before.

Thank you!

%macro Quarter_SAS(Quartercal);
%let Today_SAS  = %sysfunc(date(),Date9.);
%LET Run_Date   = %SYSFUNC(INPUTN(&Today_SAS., Date9.));
%LET Quarter_SAS  = %SYSFUNC(INTNX(MONTH, &Run_Date., 0., B), Date9.);
   %if &Quarter_SAS = ('01MAR2020') %then
      %do;
      %let Quartercal=('Q12020');
      %end;
   %else %if &Quarter_SAS = ('01AUG2020') %then
      %do;
      %let Quartercal=('Q22020');
   %end;
   %else %if &Quarter_SAS = ('01DEC2020') %then
      %do;
      %let Quartercal=('Q32020');
   %end;
   %else %if &Quarter_SAS = ('01JAN2021') %then
      %do;
      %let Quartercal=('Q42020');
   %end;
%mend Quarter_SAS;
%put &Quarter_SAS;

Re: Macro if then do question

Tom — Mon, 23 Mar 2020 14:12:19 GMT

Using the DATE9 format with the output of the %SYSFUNC() is going to generate a string that looks like:

01MAR2020

That is NEVER going to match a string that has quotes and parentheses in it like

('01MAR2020')

Re: Macro if then do question

PaigeMiller — Mon, 23 Mar 2020 14:15:06 GMT

I'm not going to re-write your entire macro code, but let me give you some general principles.

Macro variables should not be formatted (except for display in titles or labels or report). So

%let Today_SAS  = %sysfunc(date(),Date9.);

really ought to be

%let Today_SAS  = %sysfunc(date());

for any logical or arithmetical use, which is what you appear to be doing.

Next, macro variable values almost never need quotes around them, or parentheses around them. You spend a lot of time formatting and unformatting and adding quotes and then removing them. This is all unnecessary.

The exception is when you need to hard-code a specific date, such as you have 01MAR2020. Then you can use

 %if &Quarter_SAS = %sysevalf('01MAR2020'd) %then %do;

Really, start from scratch, re-write your code without formatting and without quotes and parentheses, following the above principles, and it will work a lot better with a lot less effort.

Re: Macro if then do question

Astounding — Mon, 23 Mar 2020 14:31:51 GMT

To add some detail to @Tom 's comment, this syntax is inaccurate:

   %if &Quarter_SAS = ('01MAR2020') %then
      %do;
      %let Quartercal=('Q12020');
      %end;

Macro language automatically treats characters as if they are characters. So this would be better:

   %if &Quarter_SAS = 01MAR2020 %then
      %do;
      %let Quartercal=Q12020;
      %end;

Re: Macro if then do question

IgawaKei29 — Mon, 23 Mar 2020 14:40:12 GMT

Thank you @Astounding, @PaigeMiller and @Tom. This macro logic is really interesting to me and I can see where formatting and characters can get in the way when trying to code the solution. Using a lot of these %put statements seem to help so I can see the output in my log to help formulate what I need.

Appreciate the help again! Thanks 😄

Re: Macro if then do question

PaigeMiller — Mon, 23 Mar 2020 14:42:53 GMT

Adding to my above example

%let Today_SAS  = %sysfunc(date());

If you want to see that this is correctly computing the date (and of course you can use this in more complicated date examples, such as with %sysfunc(intnx()) as well)

%put &=today_sas %sysfunc(putn(&today_sas,date7.));

Re: Macro if then do question

ballardw — Mon, 23 Mar 2020 18:56:33 GMT

Another question that may be worth considering is does this need be all macro code?

The comparisons and calculations may be easier in a DATA _NULL_ step that creates the needed macro values with call symputx.