- From: Kirkham, Pete (UK) <pete.kirkham@baesystems.com>
- Date: Thu, 13 Jan 2005 12:35:20 +0000
- To: www-rdf-interest@w3.org
- Cc: Jeremy Carroll <jjc@hplb.hpl.hp.com>, Geoff Chappell <geoff@sover.net>
With reference to http://www.w3.org/2001/sw/BestPractices/XSCH/xsch-sw-20041216/ 3.2.2 Conventionally in engineering the value '4.0' without any further error information denotes the interval [3.95, 4.05), whereas "4.0"^^ieee:float denotes [4 * (1 - 2^-25), 4 * (1 + 2^-25)) or so, so the float usually implies the decimal but not the other way round. The interval for a double is always a sub-interval of a float, so "4.0"^^ieee:float may be inferred from "4.0"^^ieee:double, but not the other way round. This is a reverse of xsd:decimal, which is taken as exact, so is suitable for accountancy. There is a trend in technical computing towards use of interval arithmetic for calculations to allow the effects of these approximations to be correctly propagated to the results. Does anyone know of a datatype for engineering values (either real intervals, or quantities with both a real interval and a units of measure facet)? Pete ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ********************************************************************
Received on Thursday, 13 January 2005 12:35:34 UTC