Re: Off by 0.00000001, Why?
- To: mathgroup at smc.vnet.net
- Subject: [mg37386] Re: [mg37378] Off by 0.00000001, Why?
- From: Murray Eisenberg <murraye at attbi.com>
- Date: Sat, 26 Oct 2002 02:03:12 -0400 (EDT)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <200210250648.CAA18199@smc.vnet.net>
- Reply-to: murray at math.umass.edu
- Sender: owner-wri-mathgroup at wolfram.com
Under Mathematica 4.2, I obtain the same result as you -- off by 1 in
the last decimal place displayed from what is shown in Maeder's book.
That was on a Pentium 4 PC. Could it be that Maeder was using a
different hardware platform, and that that alone would account for the
difference? Actually, I'd be surprised if that were the reason, because
I applied NumberForm[%, 15] to the result and obtained:
0.00157908413803032
Steven T. Hatton wrote:
> I'm going through Dr. Maeder's book, _Compute Science with Mathematica_,
> entering the examples into Mathematica and evaluating them. Here is my
> current notebook:
> http://baldur.globalsymmetry.com/proprietary/com/wri/notebooks/csm-examples.nb
>
> I've Noticed that in a few instances my results differ slightly from his. I'm
> wondering why this is happeneing. One would expect that the same algorithm
> would produce identical results regardless of the system on which it was run.
> I'm running on 4.2, and it's certain Dr Mäder was using an earlier version.
> Could that be the cause of the descrepency?
>
> One example is the very last evaluation in section 1.1.6. His book shows
> 0.00157909, whereas I get 0.00157908. This may not seem like a big deal, but
> I heard of one company immediately losing a banking contract for accumulated
> errors of this magnitude in their software. It sounds like a good way to
> lose a space probe as well.
>
> Any thoughts on this?
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street
Amherst, MA 01375
- References:
- Off by 0.00000001, Why?
- From: "Steven T. Hatton" <hattons@globalsymmetry.com>
- Off by 0.00000001, Why?