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Topic: The year of Cyber Tester
Replies: 123   Last Post: Jul 1, 2011 4:00 AM

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Axel Vogt

Posts: 1,039
Registered: 5/5/07
Re: odd simplify in Maple [was: Re: The year of Cyber Tester]
Posted: Oct 12, 2008 3:34 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Robert Israel wrote:
> Axel Vogt <&noreply@axelvogt.de> writes:
>

>> Walter Roberson wrote:
>> ...

>> > The above are simple cases of obvious defects, unless you are
>> willing to
>> > define away a complete session crash as not being a "defect".
>> Vladimir's
>> > tools are more refined, finding situations where products produce
>> > dubious or decidedly incorrect answers. I don't think it would have

>> taken
>> > very long to find such a case in Matlab 2008b: all one would have to do
>> > is pull out some of the cases one had recorded against Maple, transpose
>> > them into Matlab notation, and watch as the Maple-based Matlab

>> Symbolic
>> > Toolbox
>> > reproduced the existing Maple bug. For example, Maple 12:
>> >

>> >> log(exp(RootOf(_Z*exp(_Z)))); simplify(%);
>> > Error, (in ln) numeric exception: division by zero
>> >
>> > but evalf(RootOf(_Z*exp(_Z))) is 0, and log(exp(0)) is 0 so there

>> should
>> > be no division by zero.
>> ...
>>
>> This Maple bug steps in before log, already at
>> 'simplify( exp(RootOf(exp(_Z))) )'.

>
> That is a different bug, I think. Zeros of exp(_Z) do not exist, but Maple
> does not know that, so it essentially applies the simplification rule
> f(RootOf(f(_Z))) = 0.
>
> I think what you mean is
>
> simplify(exp(RootOf(_Z*exp(_Z))));
>
> or more generally
>
> simplify(f(RootOf(f(_Z)*g(_Z))));
>
> 0
>
> If w is a zero of f(_Z)*g(_Z), we must have f(w) = 0 or g(w) = 0. I don't
> know why Maple jumps to the conclusion that f(w) = 0 here.


Thx, f(RootOf(f(_Z))) = 0 sounds like a reason to me.

I have the errors for 'exp(RootOf(exp(f(T)))); simplify(%);' as well
and dito with a factor exp(RootOf(f*exp(_Z))) or for f a function


Date Subject Author
1/15/08
Read Re: The year of Cyber Tester
D Herring
3/10/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
3/10/08
Read Re: The year of Cyber Tester
Dave
3/11/08
Read Re: The year of Cyber Tester
nano bagonghi
3/11/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/29/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
5/26/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/20/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/13/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/22/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/22/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/24/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/26/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/29/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/5/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/5/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/6/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/8/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/23/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/23/08
Read Re: The year of Cyber Tester
Nasser Abbasi
9/7/08
Read Re: The year of Cyber Tester
Peter Pein
9/8/08
Read Re: The year of Cyber Tester
Axel Vogt
11/5/08
Read Re: The year of Cyber Tester
abc
11/10/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/23/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/24/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/25/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/26/08
Read Re: The year of Cyber Tester
clicliclic@freenet.de
8/29/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/30/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/30/08
Read Re: The year of Cyber Tester
clicliclic@freenet.de
8/30/08
Read Re: The year of Cyber Tester
clicliclic@freenet.de
8/31/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/31/08
Read Re: The year of Cyber Tester
clicliclic@freenet.de
8/31/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/31/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
9/9/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
9/9/08
Read Re: The year of Cyber Tester
clicliclic@freenet.de
10/9/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/10/08
Read Re: The year of Cyber Tester
Pfenniger Daniel
10/9/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/11/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/12/08
Read Re: The year of Cyber Tester
Walter Roberson
10/12/08
Read odd simplify in Maple [was: Re: The year of Cyber Tester]
Axel Vogt
10/12/08
Read Re: odd simplify in Maple [was: Re: The year of Cyber Tester]
Robert Israel
10/12/08
Read Re: odd simplify in Maple [was: Re: The year of Cyber Tester]
Axel Vogt
10/18/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/22/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/22/08
Read Re: The year of Cyber Tester
clicliclic@freenet.de
10/22/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
11/11/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/8/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/8/08
Read Re: The year of Cyber Tester
Any one
12/8/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/11/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/18/08
Read Re: The year of Cyber Tester
Vladimir Bondarenko
1/16/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
1/17/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
2/16/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
3/22/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/25/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/29/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/29/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/30/09
Read Re: The year of Cyber Tester
Chip Eastham
4/30/09
Read Re: The year of Cyber Tester
clicliclic@freenet.de
5/15/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/15/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/22/09
Read Re: The year of Cyber Tester
Dave
6/16/09
Read Re: The year of Cyber Tester
MeAmI.org
7/19/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/24/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/24/09
Read Re: The year of Cyber Tester
Richard Fateman
8/26/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
9/27/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/20/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
11/23/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/20/09
Read Re: The year of Cyber Tester
Vladimir Bondarenko
1/24/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
2/24/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
3/22/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/20/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
4/20/10
Read Re: The year of Cyber Tester
Guest
4/26/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
5/23/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/23/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
7/21/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/21/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
8/21/10
Read Re: The year of Cyber Tester
Peter Luschny
8/22/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
9/20/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/22/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/22/10
Read Re: The year of Cyber Tester
clicliclic@freenet.de
10/23/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
10/24/10
Read Re: The year of Cyber Tester
Albert D. Rich
10/25/10
Read Re: The year of Cyber Tester
clicliclic@freenet.de
10/26/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/1/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/23/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
12/25/10
Read Re: The year of Cyber Tester
Chip Eastham
12/25/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko
1/20/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
2/20/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
2/21/11
Read Re: The year of Cyber Tester
Richard Fateman
3/27/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
3/28/11
Read Re: The year of Cyber Tester
Richard Fateman
4/4/11
Read Re: The year of Cyber Tester
Chip Eastham
4/26/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
5/25/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/28/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/29/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/29/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/29/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/29/11
Read Re: The year of Cyber Tester
Axel Vogt
7/1/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/29/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/29/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/30/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
6/30/11
Read Re: The year of Cyber Tester
clicliclic@freenet.de
3/7/11
Read Re: The year of Cyber Tester
David Kirkby
3/22/11
Read Re: The year of Cyber Tester
Vladimir Bondarenko
9/20/10
Read Re: The year of Cyber Tester
Vladimir Bondarenko

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