From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f43e6,c7637cfdf68e766 X-Google-Attributes: gidf43e6,public X-Google-Thread: 107079,c7637cfdf68e766 X-Google-Attributes: gid107079,public X-Google-Thread: 103376,c7637cfdf68e766 X-Google-Attributes: gid103376,public X-Google-Thread: f8362,c7637cfdf68e766 X-Google-Attributes: gidf8362,public X-Google-Thread: 109d8a,c7637cfdf68e766 X-Google-Attributes: gid109d8a,public From: dewar@merv.cs.nyu.edu (Robert Dewar) Subject: Re: floating point comparison Date: 1997/08/02 Message-ID: #1/1 X-Deja-AN: 261692523 References: <33DF6F43.6EEA4806@digicomp.com> <5rqehs$g1r$1@odin.cc.pdx.edu> <33E11967.4A30@nr.net> <33E214C3.311C@pseserv3.fw.hac.com> Organization: New York University Newsgroups: comp.lang.ada,sci.math.num-analysis,comp.software-eng,comp.theory,sci.math Date: 1997-08-02T00:00:00+00:00 List-Id: Wes asks <> Of *course* it is appropriate for AQ&S to mandate this level of knowledge. I am dubious as to whether it is possible to produce a set of guidelines for fpt usage in Ada that are useful to knowlegdable professionals (the audience at which AQ&S is aimed), but for sure trying to tell people who know nothing about numerical analysis how to use fpt is a lost cause. Indeed, simple rules in this area are almost certain to be misleading and unhelpful, if not, as are several of the rules in AQ&S as it stands, downright incorrect. This is simply not an area where a simple set of rules is likely to be helpful. After all you do not look in AQ&S to learn how to program, it is expected that anyone reading this guide already knows how to program. Similarly, any style guide lines on fpt in AQ&S should reasonably be directed at those who understand floating-point and numerical analysis issues. For such an audience, the right level of discourse would probably be a rather deep discussion of how the Ada floating-point model should be used. But I doubt this audience is likely to look to AQ&S anyway. You could I suppose ask the numerics working group to redo this section, but I am dubious about whether it would be useful, and the idea that the AQ&S rules could substitute for basic knowledge is unreasonable. Of *course* the AQ&S can say "you need a level of knowledge at least equivalent to a basic course in numerical analysis" to read this section. In my view, no one who does NOT have this level of knowledge should ever use the keyword digits in Ada (unless associated with delta), or use the built in Float types! I know that may read as arrogant or dismissive, but I have seen so much chaos produced by programmers messing around with floating-point codes who have not the slighest idea what they are doing. I really think this viewpoint is no different than observing that people who have never done any programming should take a programming course before reading AQ&S.