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Re: Mathematica 8 Integration Bug

• To: mathgroup at smc.vnet.net
• Subject: [mg116068] Re: Mathematica 8 Integration Bug
• From: Chiara Boldrini <c.boldrini at gmail.com>
• Date: Tue, 1 Feb 2011 06:51:12 -0500 (EST)

Thanks,

Chiara

On Fri, Jan 28, 2011 at 10:19 PM, Daniel Lichtblau <danl at wolfram.com> wrote:

> ChiaraB wrote:
>
>> Hello,
>>
>> I needed to manipulate some probability distributions, so I ran the
>> following code:
>>
>> ccdfPL[x_, alpha_, xmin_] = (xmin/(xmin + x))^(alpha)
>>
>> Assuming[alpha \[Element] Reals && alpha > 0 &&
>>  xmin \[Element] Reals && xmin > 0, \!\(
>> \*SubsuperscriptBox[\(\[Integral]\), \(0\), \(+\[Infinity]\)]\(D[
>>    1 - ccdfPL[x, alpha, xmin], x] \[DifferentialD]x\)\)]
>>
>> According to Mathematica 8, this integral does not converge on [0,+\
>> [Infinity]), while it does converge using Mathematica 6 and
>> Mathematica 7 (it converges using paper and pencil as well :) ). Any
>> idea on how this is possible?
>>
>> Thanks,
>>
>> Chiara
>>
>
> Naughty integration code? (Wouldn't be the first time we needed to put it
> in the time out room.)
>
> I filed a bug report for this. Will investigate further.
>
> Daniel Lichtblau
> Wolfram Research
>
>
>