%例10-15  while循環的使用。  

 >> A=rand(3)
A =
    0.9501    0.4860    0.4565
    0.2311    0.8913    0.0185
    0.6068    0.7621    0.8214
>> E = 0*A; 
F = E + eye(size(E)); N = 1;
            while norm(E+F-E,1) > 0,
               E = E + F;
               F = A*F/N;
               N = N + 1;
            end
>> F
F =
  1.0e-016 *
    0.1658    0.2159    0.1001
    0.0574    0.0747    0.0346
    0.1813    0.2361    0.1094
>> E
E =
    3.1250    1.7453    1.1993
    0.6360    2.6358    0.1796
    1.8010    2.2981    2.6663
>> N
N =
    23
>>