-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Marat Khalili Sent: 08 July 2007 19:07 To: boost@lists.boost.org Subject: [boost] [rfc] Inexact quantities arithmetics
I'm developing a library for working with inexact quantities, like (0.3162 +- 0.0079), in other words, for auto-estimating the propagation of errors in calculations. I plan to release it under Boost license when ready. Any comments (including sensibility of the whole project) are welcome. <big snip>
This all looks most interesting, and would be a big step forward in handling uncertainty - but use of the word 'error' is now so-last-millenium ;-) Joking apart, this is a serious point http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=a7... http://www.teknologiportalen.dk/EN/Teknologi/Events/Workshop.htm The word error gives off some very wrong vibes, and I would strongly urge you to change to using uncertainty instead of error, despite the historial use of the word error. It *really, really* isn't an error - it is a interval of (un-)certainty. You should also see http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/29189/1/95-0368.pdf // Evan Manning (manning@alumni.caltech.edu) // Evan Marshal Manning, C/C++ Users Journal, March 1996 page 29 to 38. // original downloaded from ftp://beowulf.jpl.nasa.gov/pub/manning // This is a simple model of uncertainties, designed to // accompany an article published in C/C++ Users Journal March 1996. // A fuller collection of even fancier classes also given in UReal.h. You will see from the full code that he templates two versions, one (unusual) where the uncertainties are correlated (must add up to 100%) - as well as the normal uncorrelated situation. Both are needed I think. and FWIW some of my comments some years ago http://lists.boost.org/Archives/boost/2003/04/46828.php I built my attempt without using Boost interval library, but you might be able to use it. I also felt it was vital to store the degrees of freedom with the value and uncertainty, and I also added some other bits of information like quantization (from A/D conversion), exact values, where the uncertainty estimate came from ... Paul --- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB +44 1539561830 & SMS, Mobile +44 7714 330204 & SMS pbristow@hetp.u-net.com