Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1998
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1998

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

Search the Archive

Re: Vectors

  • To: mathgroup at smc.vnet.net
  • Subject: [mg13921] Re: [mg13894] Vectors
  • From: BobHanlon at aol.com
  • Date: Mon, 7 Sep 1998 01:22:47 -0400
  • Sender: owner-wri-mathgroup at wolfram.com

Olivier,

Check your input.

Bob Hanlon
_______________

A = {a1, a2, a3}; B = {b1, b2, b3};

Cross[A, B]

{a2 b3-a3 b2,a3 b1-a1 b3,a1 b2-a2 b1}

Cross[A, B] == -Cross[B, A]

True

Cross[A, A]

{0,0,0}

In a message dated 9/6/98 6:59:57 AM, ogeorg at imtsg12.epfl.ch wrote:

>I want to do symbolic calculation with vectors, in particular, I want to
>do a vector product.  But if I declare:
>
>   A = (a b c)
>
>and do
>
>   A x A
>
>(which should give zero), but instead I get:
>
>   Cross::"nonn1": "Not all of the arguments are vectors 
>   of required length
>
>since there's no way for mathematica to know that a, b and c represent
>numerical value and not functions or lists. Is there a way around to
>perform this kind of calculation ?


  • Prev by Date: Fourier transform
  • Next by Date: Re: Assigning a list to coefficients
  • Previous by thread: Re: Vectors
  • Next by thread: Re: Vectors