MathGroup Archive 2003

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

Search the Archive

RE: Matrix inverse not evaluating

  • To: mathgroup at smc.vnet.net
  • Subject: [mg41626] RE: [mg41593] Matrix inverse not evaluating
  • From: "David Park" <djmp at earthlink.net>
  • Date: Thu, 29 May 2003 08:13:51 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Gregory,

You are not giving us the full details. But I can guess.

The following works...

V = {{1, 2, 3}, {3, 2, 1}, {1, 0, 2}};

Inverse[V]
{{-(1/3), 1/3, 1/3}, {5/12, 1/12, -(2/3)}, 
  {1/6, -(1/6), 1/3}}

I think the following is what you probably did...

V = {{1, 2, 3}, {3, 2, 1}, {1, 0, 2}} // MatrixForm
matrix display

Inverse[V]
Inverse[matrix display]

Inverse does not evaluate when MatrixForm is wrapped around the matrix.

One solution is to write your initial definition this way...

(V = {{1, 2, 3}, {3, 2, 1}, {1, 0, 2}}) // MatrixForm
matrix display

Inverse[V]
{{-(1/3), 1/3, 1/3}, {5/12, 1/12, -(2/3)}, 
  {1/6, -(1/6), 1/3}}

The parentheses ensure that V is defined without the MatrixForm wrapper.

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/ 


From: Gregory Lypny [mailto:gregory.lypny at videotron.ca]
To: mathgroup at smc.vnet.net

Yet another newbie question: I have a 3x3 matrix called V, filled with
numbers, whose output displays correctly.  However, when I enter
Inverse[V] the output displayed is not the answer but the word Inverse
followed by the the argument matrix as Inverse[(elements of V)].  What
am I doing wrong?  Gregory


  • Prev by Date: RE: N[ ] function problem
  • Next by Date: Re: Distance between to points in r^3
  • Previous by thread: Re: Matrix inverse not evaluating
  • Next by thread: Keyboard Input