On Windows NT, 8.2 I could replicate the results found by John.

This is a typical case of the floating point representation error. To see it more clearly, consider:

177 data _null_ ; 178 x = 2.775558E-17 ; 179 put x = : 32. ; 180 run ;

x=0

Venky

On Tue, 2 Nov 2004 10:03:24 -0600, Dunn, Toby <Toby.Dunn@TEA.STATE.TX.US> wrote:

>John, > >It seems to be working for me, no sure whats going on with yoru system. > >Windows xp sas v9.1.2 > >Toby Dunn > >-----Original Message----- >From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of >Bonett, John >Sent: Tuesday, November 02, 2004 9:41 AM >To: SAS-L@LISTSERV.UGA.EDU >Subject: Expecting 0 after calculation... > > >Hello all, > >Can anyone tell me why the following code does not result in theta_min=0 >when theta_midpt=.1 or theta_max=0 when theta_midpt=-.1? I'm guessing >it is in the way var i is incremented in the do loop? >Note: if I increment from -.1 to .1 by .2 I get the results I expect. > > >%LET intv=.2; >%macro test; >Data test; >do i=-.3 to .3 by .2; >theta_midpt=i; theta_min=i-(&intv./2); theta_max=i+(&intv./2); drop i; >output; end; Run; %mend test; %test; > >Thanks in advance! >John > > > >************************************************************************ >** >This e-mail and any files transmitted with it may contain privileged or >confidential information. It is solely for use by the individual for >whom it is intended, even if addressed incorrectly. If you received this >e-mail in error, please notify the sender; do not disclose, copy, >distribute, or take any action in reliance on the contents of this >information; and delete it from your system. Any other use of this >e-mail is prohibited. Thank you for your compliance.