RE: Question about yet another bug in Sum
- To: mathgroup at smc.vnet.net
- Subject: [mg35224] RE: [mg35204] Question about yet another bug in Sum
- From: "DrBob" <majort at cox-internet.com>
- Date: Wed, 3 Jul 2002 05:13:23 -0400 (EDT)
- Reply-to: <drbob at bigfoot.com>
- Sender: owner-wri-mathgroup at wolfram.com
>>I observe that every time before it becomes stronger, Mathematica expeciences a collapse ;-) This isn't a new behavior in Version 4.2. It does the same thing in 4.1. Bobby Treat -----Original Message----- From: Vladimir Bondarenko [mailto:vvb at mail.strace.net] To: mathgroup at smc.vnet.net Subject: [mg35224] [mg35204] Question about yet another bug in Sum Hello. Mathematica is a great environment. I observe that every time before it becomes stronger, Mathematica expeciences a collapse ;-) Now we at this leg of its majestic trajectory... Here is another bug in Sum. $Version "4.2 for Microsoft Windows (February 28, 2002)" Sum[Exp[-I Pi n] n /(1 + n^2), {n, 0, Infinity}] ACTUAL: Sum::"div": "Sum does not converge." EXPECTED: -1/2*HypergeometricPFQ[{2, 1 + I, 1 - I}, {2 - I, 2 + I}, -1] CHECK-UP: N[%, 20]//Chop -0.26961050270800898180 NSum[Exp[-I Pi n] n/(1 + n^2), {n, 0, Infinity}, WorkingPrecision->20]//Chop -0.269610502708010 This bug is present in 4.1, 4.0, 3.0. Version 2.2 leaves the sum unevaluated. Can anyone explain the origin of the bug? Best, Vladimir Bondarenko