Re: QUESTION (EigenVectors)

*To*: mathgroup at smc.vnet.net*Subject*: [mg19417] Re: QUESTION (EigenVectors)*From*: adam.smith at hillsdale.edu*Date*: Mon, 23 Aug 1999 13:57:24 -0400*Organization*: Deja.com - Share what you know. Learn what you don't.*References*: <7pl79i$ch0@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Mathematica has built-in routines for finding the eigenvalues and eigenvector of any n-by-n matrix. See the help under List and Matrices -> Matrix Operations -> EigenValues, EigenVectors and EigenSystem. EigenValues[matrix] gives you the roots of the n-degree polynomial. EigenVectors[matrix] gives the EigenVector. EigenSystem[matrix] gives both the eigenvalues and corresponding eigenvector in one command. Adam Smith In article <7pl79i$ch0 at smc.vnet.net>, clangis at chat.carleton.ca (Christian Langis) wrote: > Hi there. > > I am a a computer science student; and that is probably why > this question may seem deprived of any chalenge to you. But it > is quite challenging to me. > > The question is: how do you extract the 1st EigenVector from a > 3x3 matrix (and optionally 2nd and 3rd)? > > I read a solution which forces the person to extract the 3 > roots of a 3rd degree polynomial. And this has to be done by > hand of course. > > Hence, it is possible to compute that manually. But I am rather > looking for an algorithm do carry this task, a solution which > does not involve any manual evaluation (such as root extraction). > > Therefore do you know any algorithm/source code to do that (or > know where to find it)? > > thanks > > Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't.