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Re: Re: Simple question or how Mathematica getting on my nerves.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg45937] Re: [mg45894] Re: Simple question or how Mathematica getting on my nerves.
  • From: Cheng Liu <cliu at lanl.gov>
  • Date: Fri, 30 Jan 2004 04:16:08 -0500 (EST)
  • References: <butdvt$9se$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Hi, Vladimir,

         Use NIntegrate rather than Integrate, I got the same result as 
those unnamed applications.  I saw the words eval and APPROX in the 
applications, so NIntegrate makes more sense to me.

Cheng

At 03:34 AM 1/29/2004, Vladimir Bondarenko wrote:
>gtsavdar at auth.gr (George) wrote in message news:<butdvt$9se$1 at smc.vnet.net>...
> > Although the 2 results must be the same they aren't. WHY???????
> > And not only this, but they differ by 10^21!!!!!! WHY????????
>
>
>Hello,
>
>I have a remark to the answers given by Msr Hanlon, Rowe, Noffke,
>Kozlowski and Treat whose many comment I agree with, and two
>questions about the Mathematica overall design.
>
>There are at least 2 commercial applications where the things go
>smoothly in the case at hand. I respect the request of our
>moderator Steven Christensen and not name those applications
>but the fact remains:
>
> > evalf(int(2687176093959399272413585923303421161600*(1-f)^67*f^61, f = 
> .6214 .. .5242));
> > evalf(int(2687176093959399272413585923303421161600*(1-f)^67*f^61, f = 
> 6214/10000 .. 5242/10000));
>
>-.1398383104
>-.1398383104
>
>APPROX(INT(2687176093959399272413585923303421161600*(1-f)^67*f^61, f,
>6214/10000,5242/10000))
>APPROX(INT(2687176093959399272413585923303421161600*(1-f)^67*f^61, f,
>0.6214, 0.5242))
>
>-0.1398383104
>-0.1398383104
>
>
>while for Mathematica we see
>
>
>Integrate[2687176093959399272413585923303421161600*(1 - f)^67*f^61,
>{f, 0.6214, 0.5242}]
>
>-9.37972 10^21 (* Mathematica 5.0 *)
>-9.2522 10^21  (* Mathematica 4.2.1 *)
>-7.82732 10^21 (* Mathematica 3.0 *)
>1.03892 10^23  (* Mathematica 2.2 *)
>
>I believe all of you would agree that treating the above results
>yielded by those application as pure coincidence would set before
>us a formidable challenge as the chances such random behavior
>would be some 1/10^20; thus, it's not by chance.
>
>My questions are,
>
>1) Why exactly none Mathematica version can operate in a similar way?
>
>2) Suppose, the above behavior is a feature. Had Mathematica been
>    designed in a way supporting the behavior of those two
>    systems, what would be the headaches inferred from such
>    hypothetical design?
>
>
>Best wishes,
>
>Vladimir Bondarenko
>
>GEMM architect
>Co-founder, CEO, Mathematical Director
>Cyber Tester, LLC
>
>http://www.cybertester.com/
>http://www.CAS-testing.org/
>
>.......................................................................

===================================
Cheng Liu, Ph.D.
MST-8, MS-G755
Los Alamos National Laboratory
Los Alamos, NM 87545

email: cliu at lanl.gov
Phone: (505)665-6892 (office)
        (505)667-9950 (lab)
Fax:   (505)667-8021
===================================


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