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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,cc4f25d878383cc X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-12-03 04:44:36 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!newsfeed.direct.ca!look.ca!newsfeed1.earthlink.net!newsfeed.earthlink.net!newsmaster1.prod.itd.earthlink.net!newsread1.prod.itd.earthlink.net.POSTED!not-for-mail Message-ID: <3C0B65CB.8CDD7B31@earthlink.net> From: "Marc A. Criley" Organization: Quadrus Corporation X-Mailer: Mozilla 4.73 [en] (X11; U; Linux 2.2.14-5.0 i686) X-Accept-Language: en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Another Idea for Ada 20XX References: <3C0AACCE.329CFB60@worldnet.att.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Mon, 03 Dec 2001 12:44:31 GMT NNTP-Posting-Host: 158.252.122.213 X-Complaints-To: abuse@earthlink.net X-Trace: newsread1.prod.itd.earthlink.net 1007383471 158.252.122.213 (Mon, 03 Dec 2001 04:44:31 PST) NNTP-Posting-Date: Mon, 03 Dec 2001 04:44:31 PST X-Received-Date: Mon, 03 Dec 2001 04:44:34 PST (newsmaster1.prod.itd.earthlink.net) Xref: archiver1.google.com comp.lang.ada:17330 Date: 2001-12-03T12:44:31+00:00 List-Id: James Rogers wrote: > > Take the situation of the NASA Mars probe that crashed because > of an improper mixture of British and Metric distance units. > > If the programming language used had provided the ability to > perform unit analysis the mistake would have been caught by > the compiler. Actually, no it would not have been caught by the compiler. While working on an article several months ago I exchanged some emails with an individual at Malin Space Science Systems, who knew exactly what had happened there--which is why I'd contacted him. The problem was that one program wrote a file of floating point numbers representing values in British units, which was then read by a program that expected floating point numbers representing metric units. No unit information accompanied the values in the file, they were just numbers. Marc A. Criley Senior Staff Engineer Quadrus Corporation www.quadruscorp.com