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Re: Some bugs in Mathematica

  • To: mathgroup at smc.vnet.net
  • Subject: [mg59322] Re: Some bugs in Mathematica
  • From: akhmel at hotmail.com
  • Date: Fri, 5 Aug 2005 01:22:55 -0400 (EDT)
  • References: <dcn6ho$kbr$1@smc.vnet.net><200508030520.BAA06414@smc.vnet.net> <dcscbv$q1f$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Andrzej Kozlowski wrote:
> 1. This is obviously false. Take n=1. Than your sum is
>
> Sum[(Gamma[1/2 - k ]*Gamma[k + 1/2])/
>     (Gamma[ - k ]*Gamma[k + 1]), {k, 0, 0}]
>
> which is simply Gamma[1/2]*Gamma[1/2]/(Gamma[0]*Gamma[1])
>
> The issue is what is Gamma[0]? The Gamma function has a simple pole
> at 0, so Mathematica correctly gives
>
>
> Gamma[0]
>
>
> ComplexInfinity
>
> That forces the answer to be 0, thus contradicting your claim that
> the sum is always 1.
>
> 2. This group is not a place for reporting Mathematica bugs. If you
> wan to report a bug you shoudl report it directly to WRI's technical
> support.
> This is a Mathematica discussion group. No employees of Wolfram are
> obliged to read any posting to this group or reply to them. Those who
> choose to do so, do so voluntarily because they want to help
> Mathematica users. Referring to them by name in your postings  is not
> going to make them reply  and I would guess that if you make yourself
> sound as if you were demanding rather than asking for an answer they
> are more likely to ignore you. Which they are fully entitled to do.
>
> Andrzej Kozlowski

You are right in one aspect; I made two misprints when typing formula.
Instead of Gamma[n-k-1], it should be \Pi Gamma[n-k]. I apologize for
the
confusion. Nevertheless, my claim still stands: the corrected sum is
equal
to 1, while Mathematica gives 0.

I do not accept your remark that your newsgroup is not the right place
to
expose Mathematica bugs. It looks like you're being paid by Mathematica
and
are trying to shut up any criticism. It just doesn't look good.
Mathematica
definitely needs improvement and their staff should be grateful to
people
like myself, who points out their mistakes.

Thanks,

Alex


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