From: <andreyk1_at_post.tau.ac.il>

Date: Fri, 25 Aug 2006 13:49:39 +0300

This message was sent using IMP, the Internet Messaging Program. Received on Fri Aug 25 2006 - 12:50:13 MEST

Date: Fri, 25 Aug 2006 13:49:39 +0300

Dear Lorenzo,

Thanks for solution, but this is not my case. The integral is too complicated to be done analitically. The only way is numerical calculation. Actually I can integrate between BesselJ zeroes and sum up these intervals, but it is not efficient.

Andrew.

Quoting Lorenzo Moneta <Lorenzo.Moneta_at_cern.ch>:

*> Hi Andrew,*

*>*

*> I don't know of a method for 2d with oscillatory function.*

*> Hower, you should be able for a Bessel of order 0 to solve the*

*> integral analytically,*

*> using the Bessel J0 definition*

*>*

*> see http://en.wikipedia.org/wiki/Bessel_function*

*>*

*> Cheers,*

*>*

*> Lorenzo*

*> On 24 Aug 2006, at 12:14, andreyk1_at_post.tau.ac.il wrote:*

*>*

*> >*

*> >*

*> > Dear rooters,*

*> >*

*> > I need to integrate over two dimensionl oscillating function*

*> > (TMath::BesselJ(0,x*y), 0<x<inf, 0<y<inf). I use TF1 with*

*> > IntegralMultiple, but*

*> > the answer is not stable, a change in max_points leads to a*

*> > different result. I*

*> > tried to increas the number of max_points to 1e+6 but the result is*

*> > still*

*> > unstable. Is there some method of integrating over oscillating*

*> > function with*

*> > arbitry dimensions? (in my case it is dim = 2).*

*> >*

*> >*

*> > Thanks a lot!*

*> >*

*> >*

*> > Andrew*

*> >*

*> > ----------------------------------------------------------------*

*> > This message was sent using IMP, the Internet Messaging Program.*

*> >*

*> >*

*>*

*>*

*> +++++++++++++++++++++++++++++++++++++++++++*

*> This Mail Was Scanned By Mail-seCure System*

*> at the Tel-Aviv University CC.*

*>*

This message was sent using IMP, the Internet Messaging Program. Received on Fri Aug 25 2006 - 12:50:13 MEST

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