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Re: Vectors

  • To: mathgroup at smc.vnet.net
  • Subject: [mg13914] Re: Vectors
  • From: "Allan Hayes" <hay at haystack.demon.cc.uk>
  • Date: Mon, 7 Sep 1998 01:22:40 -0400
  • References: <6ssuku$m7j@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Olivier:

Do you mean

    A = {a,b,c};
?

This gives

    Cross [A,A]

    {0,0,0}

Allan
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Allan Hayes
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-------------------------------------------------------------------------

Olivier Georg wrote in message <6ssuku$m7j at smc.vnet.net>...
>Hi,
>
>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 ?
>
>Please e-mail also, thanks,
>
>Olivier
>--
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