Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Date: Thu, 30 Jun 2005 09:47:40 -0700 From: Yitzchak Scott-Thoennes To: cygwin@cygwin.com Subject: Re: Bug in printf ? Message-ID: <20050630164740.GA3104@efn.org> References: <20050630.202057.83613389.haro@kgt.co.jp> <20050630.202554.129758646.haro@kgt.co.jp> <8864897.1120133151080.JavaMail.adm-moff@moffice2.nsc.no> <20050630.214457.02636322.haro@kgt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050630.214457.02636322.haro@kgt.co.jp> User-Agent: Mutt/1.4.2.1i X-IsSubscribed: yes On Thu, Jun 30, 2005 at 09:44:57PM +0900, haro@kgt.co.jp wrote: > ::Dealing with integers illustrates the matter more clearly. When > ::the decimal value is exactly 0.5, then printf should round to the > ::nearest *even* integer, as far as I know, so you should get > > Hi Peter, > > Thank you for your explanation. I didn't know, until now, that > rounding should be done to the "nearest *even* integer". > Need to learn every day. ;-) This is done to prevent systemic bias. However, note that http://www.opengroup.org/onlinepubs/009695399/functions/printf.html says: "The low-order digit shall be rounded in an implementation-defined manner." so while people have come to expect unbiased rounding, it isn't actually mandatory AIUI under vanilla SUSv3. Also see "What Every Computer Scientist Should Know About Floating-Point Arithmetic" at (among other places) http://docs.sun.com/source/806-3568/ncg_goldberg.html. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/