Re: Why Round[5/2]=2?
- To: mathgroup at smc.vnet.net
- Subject: [mg17487] Re: Why Round[5/2]=2?
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Mon, 10 May 1999 01:44:26 -0400
- References: <7h4j9n$ei9@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Xing Jing Li <xingjing at calvin.math.vt.edu> wrote in message news:7h4j9n$ei9 at smc.vnet.net... > While I am working on the exercises on the book _Power Programming > with Mathematica_ I noticed that Round[5/2] gave me 2. It is obviously > wrong. But how could this happen? I am using Mathematica 3.0.1 on a > Macintosh. I also tried the command"Round[5/2]" on other Macintoshes > and PCs and all them gave me 2. Is this some kind bug? Other numbers I > tried gave me the answers I expected. > > Can some one tell me what is going on? > > Thanks, > > Xing Jing Li > Xing Jing Li, The Help Browser tells us that: Round[x] gives the integer closest to x. Round rounds numbers of the form x.5 toward the nearest even integer This is consistent with what you found. But I seem to remember that some rounding rules use x.5 rounds up if x is even and down it x is odd (or vice versa). Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565