例6- 41  求矩陣的特征值分解。
解：在命令窗口中輸入如下命令，并按Enter鍵確認。
>> A=magic(4)
A =
    16     2     3    13
     5    11    10     8
     9     7     6    12
     4    14    15     1
>> [V,D]=eig(A)
V =
   -0.5000   -0.8236    0.3764   -0.2236
   -0.5000    0.4236    0.0236   -0.6708
   -0.5000    0.0236    0.4236    0.6708
   -0.5000    0.3764   -0.8236    0.2236
D =
   34.0000         0         0         0
         0    8.9443         0         0
         0         0   -8.9443         0
         0         0         0    0.0000
>> Z=A*V-V*D
Z =
  1.0e-013 *
   -0.1066    0.0711   -0.0222   -0.0154
   -0.1776    0.0577   -0.0105   -0.0264
   -0.1066    0.0247   -0.0178   -0.0380
    0.0711    0.0799        0   -0.0154
>> B=[17 3 4 2;3 1 12 6;4 12 8 7;1 2 3 4]
B =
    17     3     4     2
     3     1    12     6
     4    12     8     7
     1     2     3     4
>> [V,D]=eig(A,B)
V =
   -0.0517    0.8287    1.0000   -0.3333
   -0.3590    0.2175    0.2859   -1.0000
   -0.4474    0.0914   -0.5660    1.0000
    1.0000    1.0000   -0.7016    0.3333
D =
   -5.7955         0         0         0
         0    1.5765         0         0
         0         0    0.4054         0
         0         0         0   -0.0000
>> Z=A*V-B*V*D
Z =
  1.0e-013 *
   -0.1776    0.1066   -0.0799    0.0372
    0.1177    0.0355    0.1243   -0.0228
   -0.0089    0.0711    0.1232   -0.1031
    0.0888    0.1243    0.0600    0.0047
>>