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>