-- Wolfram Research QA process defect: Bug in Mathematica 6 - Integrate - 85 (Sin, Sinh, invalid value, multiple regression bug) - BUG THE LONG LIVER: 1996-2008 (!)
Vladimir Bondarenko
- 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 and fix efficiently bugs the long livers.
The reported here defect persists in the Mathematica versions
since at least 1996 to 2008.
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[( 3 - 3 Pi Coth[Pi] + 5 Pi Tanh[Pi] ) / 12 ]
NIntegrate[Sin[z]^4/Sinh[z]^4, {z, 0, Infinity}]
0.76578
0.76578
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N[Integrate[Sin[z]^4/Sinh[z]^4, {z, 0, Infinity}]]
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VERSION OUTPUT RESOLUTION
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Mathematica 6.0 0.64078 <----------------------------- BUG #2
Mathematica 5.2 0.76578 (compact) OK
Mathematica 4.2 Unevaluated <------------------------- BUG #1
Mathematica 3.0 0.76578 (lengthy) OK
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N[Integrate[Sin[z]^6/Sinh[z]^6, {z, 0, Infinity}]]
NIntegrate[Sin[z]^6/Sinh[z]^6, {z, 0, Infinity}]
0.709368
0.626035
N[Integrate[Sin[z]^8/Sinh[z]^8, {z, 0, Infinity}]]
NIntegrate[Sin[z]^8/Sinh[z]^8, {z, 0, Infinity}]
0.479898
0.542398
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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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