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Re: Almost symbolic computations (?)

  • To: mathgroup at smc.vnet.net
  • Subject: [mg90492] Re: Almost symbolic computations (?)
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Thu, 10 Jul 2008 07:32:05 -0400 (EDT)
  • Organization: Uni Leipzig
  • References: <g54oim$etu$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de

Hi,

and ax, ay and az should not be functions of
your space variables ? For constants the derivative
is always 0

Regards
   Jens

Barbara Da Vinci wrote:
> Dear MathGroup
> 
> This is an example of the problem
> I'm facing.
> 
> The code
> 
>    Needs["VectorAnalysis`"];
>    Head /@ {ax, ay, az}
>    A = {ax, ay, az};
>      Curl[A]
> 
> returns
> 
> {Symbol, Symbol, Symbol}
> {0, 0, 0}
> 
> Instead, I would get the
> well known symbolic form
> 
> d_y az - d_z ay
> ...
> 
> I have been trying, for
> a while, to perform string
> manipulations but that,
> of course, lays to ashes
> the possibility to recognize
> 
> d_y az + d_y az = 2 d_y az
> 
> and so on.
> 
> Any way to get out of it ?
> 
> Kind regards
> 
> 
> Barbara Da Vinci
> 


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