Date:         Fri, 4 May 2007 12:03:51 -0700
Reply-To:     "Pardee, Roy" <pardee.r@GHC.ORG>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Pardee, Roy" <pardee.r@GHC.ORG>
Subject:      Macro arithmetic problem with %eval() & %sysevalf()
Content-Type: text/plain; charset="us-ascii"

Hey All,

I've got a program in which I want to programmatically set the number of
OUTOBS in proc sql, based on two macro variables.  But I'm getting
unexpected errors--in particular on the code below I get the message
"ERROR: A character operand was found in the %EVAL function or %IF
condition where a numeric operand is required. The condition was: 10 +
2.5".

Here's a little sample that demonstrates the problem:

* =========================== ;
%macro test(NumNetwork = 10) ;
   %let dead_margin = .25 ;
   proc sql ;
      reset outobs = %eval(&NumNetwork + %sysevalf(&NumNetwork *
&dead_margin)) nowarn ;
   quit ;
%mend ;

options mprint ;

%test ;
* =========================== ;

I've tried every combination of %eval() & %sysevalf() in there, but have
not been able to get this to work.  Do I really have to go through a
datastep to do this calculation?  I don't understand that error message
in particular.

Many thanks in advance!

-Roy

Roy Pardee
Research Analyst/Programmer
Group Health Center For Health Studies (Cancer Research Network)
(206) 287-2078
Google Talk: rpardee