Re: How can I get this spiked Integral evaluated???
- To: mathgroup at smc.vnet.net
- Subject: [mg72003] Re: How can I get this spiked Integral evaluated???
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 7 Dec 2006 06:26:23 -0500 (EST)
- Organization: Uni Leipzig
- References: <el687j$2pv$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi,
try
Integrate[Exp[-x^2], {x, -900, 1000}]
witout the N* and finaly, when you have got the anlytical result
use N[]
Regards
Jens
Zeno wrote:
> This is an integral with a spike that is not in the middle of the
> integral range. Here is the integral...
>
> NIntegrate[Exp[-x^2], {x, -900, 1000}]
>
> Mathemtaica 5.2.2 gives this error message....
>
> "Numerical \integration stopping due to loss of precision. Achieved
> neither the requested \PrecisionGoal nor AccuracyGoal; suspect one of
> the following: highly \oscillatory integrand or the true value of the
> integral is 0. If your \integrand is oscillatory on a (semi-)infinite
> interval try using the option \Method->Oscillatory in NIntegrate.
> More?
>
> However, to use the option "Method->Oscillatory" one of the bounds of
> the integral must be infinity, so that would not work here. How do I
> get it to to the integral in the range -900 to 1000??
> The correct answer is 1.77245.
>