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MathGroup Archive 2007

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RE: Re: Quick integral.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg73506] RE: [mg73491] Re: Quick integral.
  • From: "Jouvenot, Fabrice" <F.Jouvenot at liverpool.ac.uk>
  • Date: Wed, 21 Feb 2007 01:33:42 -0500 (EST)
  • References: <erc23r$mv4$1@smc.vnet.net> <200702201115.GAA07658@smc.vnet.net>

Thanks for your answer.

I tried to test the different proposition that have been made, but you
are right there is a problem with my notebook. I cannot use it anymore...

Does anyone have any idea why ?

Thanks,

Fabrice.


-----Original Message-----
From: dontdont at gmail.com [mailto:dontdont at gmail.com]
Sent: 20 February 2007 11:15
To: mathgroup at smc.vnet.net
Subject: [mg73506] [mg73491] Re: Quick integral.

On Feb 19, 3:36=C2=A0am, "Jouvenot, Fabrice"
<F.Jouve... at liverpool.ac.uk>
wrote:
> Thanks for your answers.
>
> As some of you asked for the notebook here is it
> :http://www.onyrium.net/=
Mathematica/CoordScat.nb
>
> At the end there is an integral named toto[], we launch it and have an

> evaluation time of how this implementation in a large notebook will
> affect time.
>
> We want to minimize a really lot this time. We try to make more
> physics approximations, but there is certainly mathematica things we
> can do to quicker everythings.
>
> One more things to know : we do not need a large accuracy on the
> results, large errors are ok.
>
> Thanks for your help.
>
> Fabrice.

The integrand to NIntegrate seems far more complicated than the amount
of accuracy that you are asking for.  This is probably why it is so slow
to integrate.

There seem to be problems with the notebook you posted that make it
unreliable to try to evaluate.
<< Graphics`Graphics`
seems to need a semicolon at the end and there seem to be other things
that make it evaluate and produce no output, for example if it is
evaluated, changed in any tiny way, saved, and then tried to evauate
again.

toto[l_] := Sum[dNd=CF=95[l, angle=CF=95[=CE=A8, thc, 
=CE=B8source],
thc]*
   AcceptancePMT[angleLightOM[vOM,
   vlight[thc, =CE=A8, =CE=B8source, l]]], {=CE=A8,
=CF=80/2,2=CF=80,=CF=80= }];

is only slightly faster, because of the very complicated expression to
be evaluated, but produces approximately the same result as NIntegrate
evaluating across the entire interval.

dontdont at gmail.com




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