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Re: Troubles with Integrating certain functions in 5.0
*To*: mathgroup at smc.vnet.net
*Subject*: [mg49136] Re: Troubles with Integrating certain functions in 5.0
*From*: Paul Abbott <paul at physics.uwa.edu.au>
*Date*: Fri, 2 Jul 2004 02:01:53 -0400 (EDT)
*Organization*: The University of Western Australia
*References*: <cc0n0q$kvs$1@smc.vnet.net>
*Sender*: owner-wri-mathgroup at wolfram.com
In article <cc0n0q$kvs$1 at smc.vnet.net>,
mdh at media.mit.edu (Matt Hancher) wrote:
> I'm running 5.0.0.0 on OS X, and Integrate is misbehaving. Below I show
> the results of performing the same definite integral two times. The only
> difference is that I pulled out the constant factor Sqrt[E] in the second
> case. Only the second case is correct; the Struve function shouldn't be
> there in the first case.
>
> I'm pretty sure I'm not just being dumb. Anybody have any thoughts?
> I'd be curious to know how this plays out with other versions and on
> other platforms....
I recently encountered the same bug and reported it to WRI. You get the
same error with
Integrate[Exp[a Cos[t]], {t,0,Pi}]/Pi
(the Struve function should not be there) and also with
Table[Integrate[Exp[a Cos[t]] Cos[n t],{t,0,Pi}]/Pi, {n,3}]
where, in addition, the 0's are clearly incorrect.
Cheers,
Paul
>
> In: Integrate[Exp[-Sin[x]^2]*Sqrt[E], {x, 0, Pi}]
> Out: Pi ( BesselI[0, 1/2] - StruveL[0, 1/2] )
>
> Versus:
>
> In: Integrate[Exp[-Sin[x]^2], {x, 0, Pi}]*Sqrt[E]
> Out: Pi BesselI[0,1/2]
>
> Thanks for any thoughts,
> Matt
>
> Matt Hancher
> NASA Ames Research Center
> Official: mdh at email.arc.nasa.gov
> Personal: mdh at media.mit.edu
>
--
Paul Abbott Phone: +61 8 9380 2734
School of Physics, M013 Fax: +61 8 9380 1014
The University of Western Australia (CRICOS Provider No 00126G)
35 Stirling Highway
Crawley WA 6009 mailto:paul at physics.uwa.edu.au
AUSTRALIA http://physics.uwa.edu.au/~paul
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