4/6/00
9
How many eigenvalues of a random matrix are real?
>> e=eig(randn(7))
e =
   1.9771         
   1.3442         
   0.6316         
  -1.1664 + 1.3504i
  -1.1664 - 1.3504i
  -2.1461 + 0.7288i
  -2.1461 - 0.7288i
>> e=eig(randn(7))
e =
  -2.0767 + 1.1992i
  -2.0767 - 1.1992i
   2.9437         
   0.0234 + 0.4845i
   0.0234 - 0.4845i
   1.1914 + 0.3629i
   1.1914 - 0.3629i
>> e=eig(randn(7))
e =
  -2.1633         
  -0.9264
  -0. 3283
   2.5242         
   1.6230 + 0.9011i
   1.6230 - 0.9011i
   0.5467
7x7 random Gaussian
3 real                            1 real                            5 real