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Re: Re: Time for an integration

• To: mathgroup at smc.vnet.net
• Subject: [mg100960] Re: [mg100893] Re: Time for an integration
• From: DrMajorBob <btreat1 at austin.rr.com>
• Date: Thu, 18 Jun 2009 20:47:32 -0400 (EDT)
• References: <200906180848.EAA19672@smc.vnet.net>
• Reply-to: drmajorbob at bigfoot.com

More details. What does the matrix have to do with it?

Is this 4096 2-dimensional integrals, each with data points from the  
matrix? What?

Show us a tiny version of the problem. 8 times, with an 8x8 matrix, for  
instance, with all the data and code shown explicitly. Then we'd know what  
you're talking about.

Bobby

On Thu, 18 Jun 2009 03:48:34 -0500, Alexei Boulbitch  
<Alexei.Boulbitch at iee.lu> wrote:

> Hello !
>
> I have an integral to perform 4096 times: it is a 3dimensionnal integral  
> over a matrix of 4096.4096 points.
>
> It takes many hours and I still does not have the result. I made a loop  
> with NIntegrate.
>
> Is it possible that an integration loop in mathematica takes so long ?  
> Is there any ways to improve it ?
>
> Thank you
>
> Lena
>
> Hi, Lena,
> in general -yes. Think about replacing your loop by Table or Nest or  
> comparable (depending of what precisely you are doing).
> It would be helpful, if you show your code. But do not do it in its  
> original size, just do 10 times 10 by 10 or alike.
> Regards, Alexei
>



-- 
DrMajorBob at bigfoot.com

• References:
  • Re: Time for an integration
    • From: Alexei Boulbitch <Alexei.Boulbitch@iee.lu>