topic Re: error in Macro with condition in SAS Programming

error in Macro with condition

Ronein — Tue, 24 Dec 2019 06:53:55 GMT

Hello

I am using macro with condition.

In second run of the macro I get an error

31 Run=2);
ERROR: Required operator not found in expression: &condition ^=
ERROR: The macro mmacro will stop executing.

May anyone help please to solve it and understand the error

%macro mmacro(Field,factor,condition,Run);
data RawData&Run.(where=(hativa_char   ne 'Other' 
                                      and CC>5000));
set tbl1;
Simulation=max(min(&Field.*&factor.,CC),5000);
%if &condition ^= %then &condition;
Run;
%mend mmacro;

/*Run1-Have no error*/
%mmacro(Field=niz_crd_max,
factor=1.2,
condition=,
Run=1);

/*Run2-Have error*/
%mmacro(Field=niz_crd_max,
factor=1.2,
condition=%str(IF Simulation>50000 
			   AND abs(Simulation-CC)/CC>0.5
			   then Simulation=0.5*CC;),
Run=2);

Re: error in Macro with condition

Patrick — Tue, 24 Dec 2019 07:07:18 GMT

Please try to always provide sample data so we can actually run your code. Providing sample data also allows to post desired results.

I believe some quoting around macro variable &condition will resolve the issue.

data tbl1;
  cc=6000;
  hativa_char=' ';
  niz_crd_max=1;
  output;
  niz_crd_max=2;
  output;
  stop;
run;

%macro mmacro(Field,factor,condition,Run);

  data RawData&Run.;
    set tbl1;
    if hativa_char = 'Other' or CC>5000 then delete;
    Simulation=max(min(&Field.*&factor.,CC),5000);
    %if %nrbquote(&condition) ne %nrbquote() %then
      &condition;
  Run;

%mend mmacro;

options mprint;
/*Run1-Have no error*/
%mmacro(Field=niz_crd_max,
  factor=1.2,
  condition=,
  Run=1);

/*Run2-Have error*/
%mmacro(Field=niz_crd_max,
  factor=1.2,
  condition=%str(IF Simulation>50000 
  AND abs(Simulation-CC)/CC>0.5
  then Simulation=0.5*CC;),
  Run=2);

Please note that in your condition in case CC is <=0.5 you'll end up with a division by zero - which will result in SAS throwing an error.

-> if condition CC>0.5 is False then the returned value is 0

Eventually consider using the DIVIDE() function documented here.

Re: error in Macro with condition

Astounding — Tue, 24 Dec 2019 09:17:11 GMT

There are several ways to check for a null value in a macro variable. There is an entire paper on the subject (Chung & King, I believe). This is my preference:

%if %length(&condition) %then &condition;