>> A = [0 0 1 0; 0 0 0 1; 2 1 1 1; -5 2 5 -1]

A =

     0     0     1     0
     0     0     0     1
     2     1     1     1
    -5     2     5    -1

>> eig(A)

ans =

   -3.0000
   -1.0000
    1.0000
    3.0000

>> [V,D]=eig(A)

V =

   -0.0620    0.1387    0.5000    0.2236
    0.3101    0.6934   -0.5000    0.2236
    0.1861   -0.1387    0.5000    0.6708
   -0.9303   -0.6934   -0.5000    0.6708


D =

   -3.0000         0         0         0
         0   -1.0000         0         0
         0         0    1.0000         0
         0         0         0    3.0000