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From: cwk@ORCRIST.GANDALF.CS.CMU.EDU (Charles Krueger)
Newsgroups: comp.software-eng
Subject: Re: Tolerance
Summary: Simulation implies tolerance.
Message-ID: <11774@pt.cs.cmu.edu>
Date: 4 Feb 91 15:45:03 GMT
References: <1401@ucl-cs.uucp> <27A9B451.48BF@tct.uucp> <777@caslon.cs.arizona.edu>
Organization: Carnegie-Mellon University, CS/RI
Lines: 15

In article <777@caslon.cs.arizona.edu>, dave@cs.arizona.edu (Dave P. Schaumann) writes:

> I'd certainly be interested in hearing a discussion on this topic (tolerance
> implicit in software).
> 
> Numerical analysis aside, I can't imagine a single instance of "close is 
> good enough".

How about weather predictions?  In fact, any time software simulates an
external reality (this includes numerical analysis), the input and output
abstractions are probably approximations.  The designer, programmer, and
user should all understand that there are tolerances.  These tolerances
should be quantified.

What goes on inside the computer, however, is still as precise as ever.