MathGroup Archive 2003

[Date Index] [Thread Index] [Author Index]

Search the Archive

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


  • Prev by Date: mathematica fonts error
  • Next by Date: Re: Odd behavior (bug?) with Exp[-x^2} and Erf
  • Previous by thread: Numerical Divergence
  • Next by thread: Re: Margins in DensityGraphics[] et al.