Re: Numerical Divergence
- To: mathgroup at smc.vnet.net
- Subject: [mg42940] Re: Numerical Divergence
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Tue, 5 Aug 2003 02:04:54 -0400 (EDT)
- References: <paul-40549A.21133703082003@news.uwa.edu.au>
- Sender: owner-wri-mathgroup at wolfram.com
>I've made a couple of attempts at writing a function
>
>NDiv[f_List, x:{_Symbol..}, h_Real][p:{_?NumericQ..}]
>
>that computes a numerical approximation of div(f) at p, using central
>differences with stepsize h. My (successful) attempts have used (1) Tr
>and (2) MapIndexed, and neither is very fast.
Can't you use NDSolve`FiniteDifferenceDerivative? Have a look at the
advanced documentation for NDSolve in 5.0.
Cheers,
Paul