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: 109d8a,c7637cfdf68e766 X-Google-Attributes: gid109d8a,public X-Google-Thread: f43e6,c7637cfdf68e766 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,c7637cfdf68e766 X-Google-Attributes: gid103376,public X-Google-Thread: 107079,c7637cfdf68e766 X-Google-Attributes: gid107079,public X-Google-Thread: f8362,c7637cfdf68e766 X-Google-Attributes: gidf8362,public From: dewar@merv.cs.nyu.edu (Robert Dewar) Subject: Re: floating point comparison Date: 1997/09/07 Message-ID: #1/1 X-Deja-AN: 270495751 References: <5ud3mc$5d2$1@news.fsu.edu> <5uknb2$cnp$1@cnn.nas.nasa.gov> Distribution: inet Organization: New York University Newsgroups: comp.lang.ada,sci.math.num-analysis,comp.software-eng,comp.theory,sci.math Date: 1997-09-07T00:00:00+00:00 List-Id: << If you are doing matrix operations, then you can get good error estimates from commercial packages without doing much work. If your error margins are large, then you may need to find out the condition number of your matrix (or matrices), and see if you can reduce this. It may turn out that the nature of the problem you are trying to solve is fundamentally prone to error.>> This point cannot be overemphasized. Nearly all standard numerical calculations that most people typically need to perform have been programmed to death over the years by people who really understand this stuff (rounding errors, floating-point etc), and whereever possible, you should borrow this expertise, and use standard library routines, rather than rolling your own.