topic Re: How to resolve a macro variable to a range or list of values in SAS Programming

How to resolve a macro variable to a range or list of values

moreka — Fri, 19 Oct 2018 14:06:49 GMT

I'm not sure if I've worded the question correctly, but what I'm trying to do is use the in() operator to compare the var_dt to the birth_dt or the day after. I think it's mainly a problem with not using actual values with the in() operator, but I'm not sure how to get the birth_dt and birth_dt+1 to be resolved/evaluated as their internal values.

I'm guessing there needs to be something added to or changed regarding the %let statement, but any suggestions would be appreciated!

Thanks!

options minoperator mindelimiter=',';
data tt; set t;
%macro inf;
%let birthrange = (birth_dt, birth_dt+1);
%let i=1;
if (var=1 and var_dt in(&birthrange) then do; infect&i.=101; i=%eval(&i.+1); end;
if (vax=1 and vax_dt in(&birthrange) then do; infect&i.=102; i=%eval(&i.+1); end;
%mend;
%inf;
run;

Using SAS 9.4.

Re: How to resolve a macro variable to a range or list of values

RW9 — Fri, 19 Oct 2018 14:31:47 GMT

What is it your actually trying to achieve. test data, required output etc. The code you present is not a good method of working. Never create macros within other stesp for instance, its just very messy. Define macro variables at the top of a program outside the other code for readability.

You also cannot mix datastep and macro language like that. Macro is nothing more than a find replace text mechanism which generates code, it cannot interact with the compiled datastep language as it does not exist at that point. So where is birthdt coming from, the dataset. Then use datastep language:

data tt; 
  set t;
  array infect{2} 8.;
  do i=birth_dt to birth_dt+1;
    if var=1 and var_dt in (i) then infect{i}=101; 
    if vax=1 and vax_dt in(i) then infect{i}=102;
  end;
run;

Do note, its far simpler for you to post working test data, then show what you want than for us to try to guess.

Re: How to resolve a macro variable to a range or list of values

Astounding — Fri, 19 Oct 2018 14:35:02 GMT

You have several issues here. For starters, you have an extra set of parentheses ... one on the definition of &BIRTHRANGE, and another following the IN operator. Regardless, IN does not work on a set of expressions, only on a list of hard-coded values. And %EVAL does not execute in the middle of a DATA step. It only executes ahead of time on the original value of &I to determine what statements belong in the DATA step.

Luckily, you can avoid all of these issues by avoiding macro language entirely. Here is the approach:

data tt;

set t;

i=1;

array infect {2};

array dates {2} var_dt vax_dt;

if var=1 then do k=1 to dim(dates);

if (birth_dt <= dates{k} <= birth_dt + 1) then infect{k}=1;

end;

drop k;

run;

It's easily expandable if you are actually dealing with more variables.

Re: How to resolve a macro variable to a range or list of values

ballardw — Fri, 19 Oct 2018 14:42:49 GMT

@moreka wrote:

I'm not sure if I've worded the question correctly, but what I'm trying to do is use the in() operator to compare the var_dt to the birth_dt or the day after. I think it's mainly a problem with not using actual values with the in() operator, but I'm not sure how to get the birth_dt and birth_dt+1 to be resolved/evaluated as their internal values.

I'm guessing there needs to be something added to or changed regarding the %let statement, but any suggestions would be appreciated!

Thanks!
options minoperator mindelimiter=',';
data tt; set t;
%macro inf;
%let birthrange = (birth_dt, birth_dt+1);
%let i=1;
if (var=1 and var_dt in(&birthrange) then do; infect&i.=101; i=%eval(&i.+1); end;
if (vax=1 and vax_dt in(&birthrange) then do; infect&i.=102; i=%eval(&i.+1); end;
%mend;
%inf;
run; 
Using SAS 9.4.

Assuming that birth_dt is an actual date value and in the data set then the comparison :

if (var=1 and (birth_dt le var_dt le (birth_dt + 1))   ) then ...

should work