Re: RE: Re: Re: Accuracy and Precision

*To*: mathgroup at smc.vnet.net*Subject*: [mg37117] Re: [mg37090] RE: [mg37076] Re: [mg37058] Re: Accuracy and Precision*From*: Selwyn Hollis <selwynh at earthlink.net>*Date*: Thu, 10 Oct 2002 03:20:56 -0400 (EDT)*References*: <200210090925.FAA17147@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

DrBob wrote: > Let's be realistic. If you want 60 digits of precision, too bad! -- in > the real world. There's nothing we can measure that closely. Drug > concentrations in clinical trials are generally measured within 15%, for > instance. Even machine precision is more than can be realistically > expected in any application I can think of. Even getting a satellite to > Jupiter probably involves more error in the final result than machine > precision. (If not, it's because we rely on ongoing corrections and > natural factors that put the satellite where it should be, such as > gravity drawing it toward each rendezvous -- not on that kind of > precision in propulsion or guidance.) > > So... unless all numerics in a problem have a theoretical origin, and > could be represented in Mathematica as Infinite precision expressions... > all this talk of higher-precision computation seems futile. ...Except in the very rare instance when one needs to do intermediate calculations with, e.g., 60 digits of precision in order to get only a few correct digits of the final answer. The length of this thread is surely proof of the need for a definitive reference on the topic. Has there been a Mathematica-centered numerical analysis book published since Skeel & Keiper? --- Selwyn Hollis

**References**:**RE: Re: Re: Accuracy and Precision***From:*"DrBob" <drbob@bigfoot.com>