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: 103376,369f8d7191bede27 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-02-20 02:27:20 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.freenet.de!news.tu-darmstadt.de!news.belwue.de!news.uni-stuttgart.de!not-for-mail From: Peter Hermann Newsgroups: comp.lang.ada Subject: Re: precision Date: Thu, 20 Feb 2003 10:27:19 +0000 (UTC) Organization: Comp.Center (RUS), U of Stuttgart, FRG Message-ID: References: NNTP-Posting-Host: iris16.csv.ica.uni-stuttgart.de X-Trace: news.uni-stuttgart.de 1045736839 8555 129.69.118.32 (20 Feb 2003 10:27:19 GMT) X-Complaints-To: news@news.uni-stuttgart.de NNTP-Posting-Date: Thu, 20 Feb 2003 10:27:19 +0000 (UTC) User-Agent: tin/pre-1.4-980117 (UNIX) (IRIX/6.5 (IP22)) Xref: archiver1.google.com comp.lang.ada:34267 Date: 2003-02-20T10:27:19+00:00 List-Id: >> What is precision of float means? >> My understanding is that if precision is 6 digits then 1.0 and >> 1.0000001 are same!!! Please let me know whether my understanding is 1 23456 = decimal position >> right.If not then what it means? > Approximately. For exact information, see RM 3.5.7. and more (-: The compiler is required to map the mantissa to AT LEAST 10 decimal digits, which means for binary representation a binary mantissa of at least 6/lg2 = 6/0.301... = 19.93... giving AT LEAST 20 binary digits. However the chosen mantissa length depends very much on the implementation. On 32bit floating point you may have a 23 or 24 bit mantissa where as on a 60 or 64 bit smallest floating point (e.g. CDC, Cray) your smallest mantissa has 48 bits. In this case 1.0 and 1.0000001 will be "different" :-) -- --Peter Hermann(49)0711-685-3611 fax3758 ica2ph@csv.ica.uni-stuttgart.de --Pfaffenwaldring 27 Raum 114, D-70569 Stuttgart Uni Computeranwendungen --http://www.csv.ica.uni-stuttgart.de/homes/ph/ --Team Ada: "C'mon people let the world begin" (Paul McCartney)