Date:         Fri, 15 Jun 2007 11:32:21 -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:      Re: mistakes in SAS that don't generate errors
Comments: To: "ckxplus@yahoo.com" <ckxplus@YAHOO.COM>
In-Reply-To:  A<1181894449.459835.142190@c77g2000hse.googlegroups.com>
Content-Type: text/plain; charset="us-ascii"

This one is my favorite--I found something like this in a real program:

  data interesting_diagnoses ;
    set all_diagnoses ;
    if dx_code = '300.4' or '400.3' or '900' or '111' ;
  run ;

That if statement is totally ineffectual--the text literals there get
converted into numbers, which evaluate to a logical 'true', and so all
of all_diagnoses winds up in interesting_diagnoses b/c of the
(incorrectly expressed) logical condition there...

-Roy

-----Original Message-----
From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of
ckxplus@yahoo.com
Sent: Friday, June 15, 2007 1:01 AM
To: SAS-L@LISTSERV.UGA.EDU
Subject: mistakes in SAS that don't generate errors

I'm looking for ways to produce unexpected results in SAS that don't
generate an error or warning message. Your syntax is fine, it works as
SAS intended but not as you intended. Three examples:

* Inadvertantly respecify a user-defined format. (This does generate a
note to the log that an existing format has been overwritten but that's
easy to overlook).

* Using a "numbered range list" in a function, e.g. "sum(x1-x5)". This
will calculate the sum of x1 minus x5, "sum(of x1-x5)" caculates the sum
of x1 to x5.

* Forgetting that missing values are represented by minus infinity in
comparisons.

Are there other nice examples of SAS syntax that looks like it does what
you want it to at first glance or with insufficient coffee?

John Hendrickx