Re: Question about vector analysis in Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg59915] Re: [mg59854] Question about vector analysis in Mathematica
- From: "benshimo at bgumail.bgu.ac.il" <bsyehuda at gmail.com>
- Date: Thu, 25 Aug 2005 06:34:05 -0400 (EDT)
- References: <200508241030.GAA11956@smc.vnet.net>
- Reply-to: benshimo at bgumail.bgu.ac.il
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
First, I'm sure you have a typo, since
CrossProduct[{1,0,0},{1,0,0}]
returns
{0,0,0}
as expected (cross prosuct between any two parallel vectors is 0, isn't
it?).
Second, you wanted to test
CrossProduct[{0,0,1},{1,0,0}, Cylindrical] (say a cross product between a
unit verctor in the z direction to a unit vector in the radial direction,
actually with angle 0, so it is a unit vector in the positive x direction).
So you shouldn;t be embarrased that Mathematica returns the correct result,
that is, a unit vector in the positive y direction (angle Pi/2 and a unit
magnitude).
remember, a unit vector in the angular dimension is not a really a vector.
good luck
yehuda
On 8/24/05, Steeve Brechmann (schumi) <steevebrechmann at yahoo.ca> wrote:
>
>
> Hi everyone,
>
> I have some weird problems in using Mathematica to do some vector
> analysis...perhaps its my lack of knowledge :) but i want to be sure.
>
> Needs["Calculus'VectorAnalysis' "]
> SetCoordinates[Cylindrical[r,phi,z]];
>
> I want to check that the cross product of the basis vector z and r give
> phi, i.e :
>
> CrossProduct[{1,0,0},{1,0,0}] = {1,Pi/2,0}
>
> Why this result ?
>
> Does a vector in cylindrical coordinates be {Ar, Aphi, Az} ?
>
> Thanks for your help.
>
>
> Steeve Brechmann von Brechenmacher,
> D=E9partement de physique, Universit=E9 Laval,
> Laboratoire de Physique Th=E9orique (LAPHYT),
> Centre d'Optique et Photonique Laser (COPL),
> Courriel : steevebrechmann at yahoo.ca
> Bureau : 656-2131 poste 4139
> Pagette : 890-7241
> T=E9l.: 527-7258
>
>
>
- References:
- Question about vector analysis in Mathematica
- From: "Steeve Brechmann \(schumi\)" <steevebrechmann@yahoo.ca>
- Question about vector analysis in Mathematica