1> [-3; 4; 2]/sqrt(29)
ans =

  -0.55709
   0.74278
   0.37139



2> help eig
`eig' is a function from the file C:\Programmi\3.2.4_gcc-4.4.0\libexec\octave\3.2.4\oct\i686-pc-mingw32\eig.oct

 -- Loadable Function: LAMBDA = eig (A)
 -- Loadable Function: LAMBDA = eig (A, B)
 -- Loadable Function: [V, LAMBDA] = eig (A)
 -- Loadable Function: [V, LAMBDA] = eig (A, B)
     The eigenvalues (and eigenvectors) of a matrix are computed in a
     several step process which begins with a Hessenberg decomposition,
     followed by a Schur decomposition, from which the eigenvalues are
     apparent.  The eigenvectors, when desired, are computed by further
     manipulations of the Schur decomposition.

     The eigenvalues returned by `eig' are not ordered.

     See also: eigs



Additional help for built-in functions and operators is
available in the on-line version of the manual.  Use the command
`doc <topic>' to search the manual index.

Help and information about Octave is also available on the WWW
at http://www.octave.org and via the help@octave.org
mailing list.


3> A=[0 2 -1; 2 -1 1; 2 -1 3]
A =

   0   2  -1
   2  -1   1
   2  -1   3



4> [V, lambda]=eig(A)
V =

  -0.55709 + 0.00000i   0.44721 - 0.00000i   0.44721 + 0.00000i
   0.74278 + 0.00000i   0.00000 - 0.00000i   0.00000 + 0.00000i
   0.37139 + 0.00000i  -0.89443 + 0.00000i  -0.89443 - 0.00000i

lambda =

Diagonal Matrix

  -2.0000 + 0.0000i                  0                  0
                  0   2.0000 + 0.0000i                  0
                  0                  0   2.0000 - 0.0000i



5> % le colonne di V sono gli autovettori, mentre sulla diagonale di lambda si trovano gli autovalori (ad ogni autovalore della colonna di Lambda corrisponde l'autovettore su V) 


5> quit