From: "trans.  (T. Onoma)" <transami@...>
Date: 2004-10-16T09:58:57+09:00
Subject: Re: Rounding to X digits

On Friday 15 October 2004 07:23 pm, markus@reality.com wrote:
| >     puts 0.5.round             #=> 1
| >     puts sprintf("%.0f", 0.5)  #=> 0
|
|      Both are (IIRC) ISO 31-0 conformant, but one uses ISO 31-0 B.3 rule A
| and the other uses ISO 31-0 B.3 rule B.
|
|      That said, one of the rules (the one sprintf uses, to round down
| following even digits is an abomination and should be eliminated from the
| face of the earth.  nnn.nn5 should ALWAYS round up and rounded values
| should not be re-rounded (which is what the contrary rule assumes is
| happening).

Apparently the idea of even vs. odd rounding was to help prevent "inflational" 
rounding --successive rounding pushing values upward. I think K&R actually 
supported the idea. I'm not sure how I feel about it.

T.