Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2006
*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 2006

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

Search the Archive

Can't multiply non-square matrices.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg64549] Can't multiply non-square matrices.
  • From: Chris Young <c1572young at earthlink.net>
  • Date: Wed, 22 Feb 2006 05:58:31 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Is there a way to multiply non-square matrices? E.g., a 3-row by 2-row 
matrix times a 2-row by 1-row matrix should yield a 3-row by 1-row 
matrix, if I remember my linear algebra correctly.

Instead when I do something like

   (a  b) (c)
          (d)

I get an error involving "Thread::tdlen":

Thread::tdlen: Objects of unequal length in {{a, b}}\{{c}, {d}} cannot be \
combined.

(The "(c)" and "(d)" above represent a 2-dimensional column vector, 
with one pair of parenthese around them.)

I entered the line
<< LinearAlgebra`MatrixManipulation`
but this doesn't seem to help.

Any help appreciated.

Chris Young


  • Prev by Date: Also force AxesOrigin to be in the lower right corner?
  • Next by Date: Re: SetOptions with Column
  • Previous by thread: Re: Also force AxesOrigin to be in the lower right corner?
  • Next by thread: Re: Can't multiply non-square matrices.