%IF Macro Not Working

[BrentonCSmith]

My %IF macro is not working.  .1 should be > 0 but in this macro it executes the %ELSE conditional.  If I Enter 1, the %IF condition is excuted.  The problem is that .1  is GT 0.  It if late, but the message "%IF condition .1 > 0 is FALSE" doesn't make sense to these tired eyes.

%macro ApplyTax(Tax,TRate,AnnualBenefit);

   %if .1    > 0 %then put "Is Greater";
                 %else put "is less than";
    ;             
   %if &TRate> 0 %then put "Is Greater";
                 %else put "is less than";
    ;

%mend;

Data DS;
  %ApplyTax(dsvar,.1,1000);
  run;

Here is the MPRINT;

151 Data DS;

152 %ApplyTax(dsvar,.1,1000);

MLOGIC(APPLYTAX): Beginning execution.

MLOGIC(APPLYTAX): Parameter TAX has value dsvar

MLOGIC(APPLYTAX): Parameter TRATE has value .1

MLOGIC(APPLYTAX): Parameter ANNUALBENEFIT has value 1000

MLOGIC(APPLYTAX): %IF condition .1 > 0 is FALSE

MPRINT(APPLYTAX): put "is less than" ;

SYMBOLGEN: Macro variable TRATE resolves to .1

MLOGIC(APPLYTAX): %IF condition &TRate> 0 is FALSE

MPRINT(APPLYTAX): put "is less than" ;

MLOGIC(APPLYTAX): Ending execution.

153 run;

[Tom · Accepted solution]

It is doing what you asked it to do. The ASCII code for a period is less than the code for the zero character.

2    data _null_;
3      a='.1';
4      b='0';
5      put (a b) (= $hex.);
6    run;

a=2E31 b=30

If you want to try to compare floating point values in macro code you need to use %SYSEVALF()

%if %sysevalf( .1 > 0) ...

[RW9]

"If you want to try to compare floating point values" - Or of course, do data processing in datastep where it belongs, where the data types are present for such data and where functions are there to perform such processing.

[BrentonCSmith]

thanks!

[Kurt_Bremser]

Automatic arithmetic evaluation in a %if condition will only be done when integers are used. In all other cases, you need to assist the macro compiler as @Tom suggested.

(this works as intended)

%if 23 > 3 %then %do; %put yes; %end;