-- Wolfram Research QA process defect: Bug in Mathematica 6 - Integrate - 102 (Sin, Sinh, invalid value, MULTIPLE regression bug) - BUG THE LONG LIVER: 1996-2008 (!)
Vladimir Bondarenko
If the same bugs exists through numerous software releases,
I think that is valuable public information.
It just should not happen.
-- Brad Cooper
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-- NOT FIXED BUGS ARE DANGEROUS: THEY TEND TO GET MORE SEVERE --
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Quality of CASs is our #1 care.
So our little demo continues.... Hello again from the VM machine
which hopefully soon will be used by CAS manufacturers to the
benefit of their customers.
This example demonstrates YET ANOTHER case of bad defects in the
Wolfram Research Quality Assurance process. Consider, it cannot
trap & fix efficiently MULTIPLE regression bugs the long livers.
This is also an example of a MULTIPLE regression bug when the
invalid answer is now here, now not depending on the concrete
version.
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N[ (Pi Coth[Pi] - 1)/2 ]
NIntegrate[Sin[z]^2/Sinh[z]^2, {z, 0, Infinity}]
1.07667
1.07667
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N[Integrate[Sin[z]^2/Sinh[z]^2, {z, 0, Infinity}]]
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VERSION OUTPUT RESOLUTION
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Mathematica 6.0 1.32667 <----------------------------- BUG #2
Mathematica 5.2 Correct answer (compact, 1.07667) OK
Mathematica 4.2 Unevaluated <------------------------- BUG #1
Mathematica 3.0 Correct answer (lengthy, 1.07667) OK
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Best wishes,
Vladimir Bondarenko
VM and GEMM architect
Co-founder, CEO, Mathematical Director
http://www.cybertester.com/ Cyber Tester, LLC
http://maple.bug-list.org/ Maple Bugs Encyclopaedia
http://www.CAS-testing.org/ CAS Testing
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"We must understand that technologies
like these are the way of the future."
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sashap
Want to point out that you have already informed about this
bug in 'Bug in Mathematica 6 - Integrate - 85' where t
he power was 4 instead of 2. The incorrect answer differs from
the correct one by a rational number, namely 1/4.
Oleksandr
>
> -----------------------------------------------------------------
> VERSION OUTPUT RESOLUTION
> -----------------------------------------------------------------
>
> Mathematica 6.0 1.32667 <----------------------------- BUG #2
>
> Mathematica 5.2 Correct answer (compact, 1.07667) OK
>
> Mathematica 4.2 Unevaluated <------------------------- BUG #1
>
> Mathematica 3.0 Correct answer (lengthy, 1.07667) OK
>
> -----------------------------------------------------------------
>
> Best wishes,
>
> Vladimir Bondarenko
>
> VM and GEMM architect
> Co-founder, CEO, Mathematical Director
>
> http://www.cybertester.com/ Cyber Tester, LLChttp://maple.bug-list.org/ Maple Bugs Encyclopaediahttp://www.CAS-testing.org/ CAS Testing
Vladimir Bondarenko
Much thanks for pointing out that a duplicate
http://groups.google.com/group/sci.math.symbolic/browse_thread/thread/b0fbbd1a11ad9261
is posted!
By the way, you also pointed out again a solid reason why we
the human beings should be, in the long run, expelled, once
and for all, out of software quality assurance process as the
weakest link. Our human short-term memory has a ridiculously
small size to support an efficient QA process.
Personally, I start feeling that I need to find some extra
resource to add automation/verification for posting. This way,
Cyber Tester could report up to several distinct CAS defects
daily :) Say, 10 distinct Maple 12 defects a day... during a
year.... Impressive, ah?
This my extra automation thought will be undoubtedly met with
some great joy (not to say a tumult of rejoicing) by many if
not almost all readers of the Google Groups, right?! :)))
So, back to Mathematica improvement, we replace this Sin/Sinh
integration defect with other Sin/Sinh integration defect...
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N[Pi/2 (BesselI[0, 1] - StruveL[0, 1])]
NIntegrate[Sin[Sinh[z]], {z, 0, 7}]
0.873084
0.873278
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Integrate[Sin[Sinh[z]], {z, 0, Infinity}]
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VERSION OUTPUT RESOLUTION
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Mathematica 6.0 Unevaluated <---------------------------- BUG
Mathematica 5.2 Unevaluated <---------------------------- BUG
Mathematica 4.2 Unevaluated <---------------------------- BUG
Mathematica 3.0 Unevaluated OK
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Explanation.
The same output ("Unevaluated") is interpreted as both normal and
defective in accordance with our extended point of view of bug we
had described, taking into account its economical aspect.
In 1996, none of computer algebra systems was able to calculate
the integral correctly; thus, there's no defect in Mathematica 3.
However, all Maple versions since 1997 to 2007 calculate this
integral correctly while none of the Mathematica version does it.
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Best wishes,
Vladimir
--
Vladimir Bondarenko
VM and GEMM architect
Co-founder, CEO, Mathematical Director
http://www.cybertester.com/ Cyber Tester, LLC
http://maple.bug-list.org/ Maple Bugs Encyclopaedia
http://www.CAS-testing.org/ CAS Testing
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"We must understand that technologies
like these are the way of the future."
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> >http://www.cybertester.com/Cyber Tester, LLChttp://maple.bug-list.org/ Maple Bugs Encyclopaediahttp://www.CAS-testing.org/CAS Testing
>
> > -----------------------------------------------------------------
>
> > "We must understand that technologies
> > like these are the way of the future."
>
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