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Re: NIntegrate or For or Special Function?

• To: mathgroup at smc.vnet.net
• Subject: [mg47706] Re: NIntegrate or For or Special Function?
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Fri, 23 Apr 2004 02:30:35 -0400 (EDT)
• Organization: Universitaet Leipzig
• References: <c67qg0$h0a$1@smc.vnet.net>
• Reply-to: kuska at informatik.uni-leipzig.de
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

the most time in computational quantum mechanics has spend
to compute the matrix elements.

You can try to use existing symmetry relations (Hermitian)
and/or recursion relations for the integrals derived from the
Bessel, Hankel and Kelvin function recursions.

Regards
  Jens



Matt Swingle wrote:
> 
> I am constructing filling entries in a matrix using For loops.  The
> individual entries come from integrating Bessel, Hankel and Kelvin
> functions numerically with NIntegrate.  A 100x100 matrix takes a few hours
> to run?  Is my procedural way of doing things to blame?  Is it the
> specialty functions (Bessel etc)?  Is it simply NIntegrate?  Would anyone
> be willing to look at my awful code?
> 
> Any help would be greatly appreciated.
> 
> Matt Swingle
> mss4 at duke.edu