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Re: Dot product confusion

  • To: mathgroup at smc.vnet.net
  • Subject: [mg109942] Re: Dot product confusion
  • From: Alois Steindl <Alois.Steindl at tuwien.ac.at>
  • Date: Wed, 26 May 2010 07:07:03 -0400 (EDT)
  • References: <htg90l$k7h$1@smc.vnet.net>

Hello,
your assumptions seem to be wrong.
The dot product in Mathematica isn't just "the inner product, but the
matrix product, in your case
ptsa*v or v*ptsa.
In the first case v is considered as column vector, in the second one as
row vector.
Matrix products are rarely abelian.

Alois

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Inst. for Mechanics and Mechatronics     Fax.: +43 (1) 58801 / 32598
Vienna University of Technology,         A-1040 Wiedner Hauptstr. 8-10   


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