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AW: Re: Integrate returns 0

• To: mathgroup at smc.vnet.net
• Subject: [mg23948] AW: [mg23935] Re: Integrate returns 0
• From: Klamser at t-online.de (Peter Klamser)
• Date: Sun, 18 Jun 2000 03:00:34 -0400 (EDT)
• Disposition-notification-to: "Peter Klamser" <klamser@t-online.de>
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

Jens-Peer Kuska [kuska at informatik.uni-leipzig.de] wrote on a similar
question:

Hi,

you *must* triangulate irregular data. If it is too slow you should
look on Tom Wickham-Jones packages -- there is a Delaunay triangulation
in a C program that much faster than the pure Mathematica version

http://www.mathsource.com/Content/Enhancements/Graphics/3D/0208-976


Regards, Peter Klamser

-----Ursprüngliche Nachricht-----
Von: Jens-Peer Kuska [mailto:kuska at informatik.uni-leipzig.de]
Gesendet: Freitag, 16. Juni 2000 06:57
An: mathgroup at smc.vnet.net
Betreff: [mg23935] Re: Integrate returns 0


Hi,

a bug the integral is never zero.

Regards
  Jens
"Felix E. Klee" wrote:
>
> Hi,
>
> when I define the function
>     f[x_,n_]:=D[Exp[-x^2],{x,n}]^2
> and execute
>     Integrate[f[x,n],{x,-Infinity,Infinity}]
> the result is
>     0
>
> However this is not correct for all parameters n since
>     Integrate[f[x,1],{x,-Infinity,Infinity}]
> returns
>     Sqrt[Pi/2]
>
> Is this a bug in Mathematica or am I doing something wrong?
>
> TIA,
>
> Felix