A=[34 44 23;8 34 23;34 55 2] A =
34 44 23 8 34 23 34 55 2
>> tril(A) ans =
34 0 8 34 34 55
>> triu(A)
ans =
34 44 0 34 0 0
>> diag(A)
ans =
34 34 2 norm(A) ans =
94.5106
>> rank(A) ans =
3
0 0 2 23 23 2 11
>> det(A)
ans =
-23462
>> trace(A)
ans = 70
>> null(A) ans =
Empty matrix: 3-by-0
>> eig(A) ans =
80.1587 12.7671 -22.9257
>> poly(A)
ans =
1.0e+004 *
0.0001 -0.0070 -0.1107 2.3462
>> logm(A)
Warning: Principal matrix logarithm is not defined for A with nonpositive real eigenvalues. A non-principal matrix logarithm is returned. > In funm at 153 In logm at 27
ans =
3.1909 + 0.1314i 1.2707 + 0.1437i 0.5011 - 0.2538i
12
0.4648 + 0.4974i 3.3955 + 0.5438i 0.1504 - 0.9608i 0.2935 - 1.2769i 0.8069 - 1.3960i 3.4768 + 2.4663i
>> fumn(A)
??? Undefined command/function 'fumn'.
>> inv(A)
ans =
0.0510 -0.0502 -0.0098 -0.0326 0.0304 0.0255 0.0305 0.0159 -0.0343
>> cond(A)
ans =
8.5072
>> chol(A)
??? Error using ==> chol
Matrix must be positive definite.
>> lu(A)
ans =
34.0000 44.0000 23.0000 0.2353 23.6471 17.5882 1.0000 0.4652 -29.1816
>> pinv(A) ans =
0.0510 -0.0502 -0.0098 -0.0326 0.0304 0.0255 0.0305 0.0159 -0.0343
>> svd(A)
ans =
13
94.5106 22.3456 11.1095
>> expm(A) ans =
1.0e+034 *
2.1897 4.3968 1.9382 1.3154 2.6412 1.1643 1.8782 3.7712 1.6625
>> sqrtm(A)
ans =
5.2379 + 0.2003i 3.4795 + 0.2190i 1.8946 - 0.3869i 0.5241 + 0.7581i 5.1429 + 0.8288i 2.0575 - 1.4644i 3.0084 - 1.9461i 4.7123 - 2.1276i 2.1454 + 3.7589i >>
016多项式的计算：
A=[34 44 23;8 34 23;34 55 2] A =
34 44 23 8 34 23 34 55 2
>> P=poly(A) P =
1.0e+004 *
0.0001 -0.0070 -0.1107 2.3462
14
>> PPA=poly2str(P,'X')
PPA =
X^3 - 70 X^2 - 1107 X + 23462
017多项式的运算： p=[2 6 8 3];w=[32 56 0 2]; >> m=conv(p,w) m =
64 304 592 548
>> [q,r]=deconv(w,p) q = 16 r =
0 -40 -128 -46
>> dp=polyder(w) dp =
96 112 0
>> [num,den]=polyder(w,p)
num =
80 512 724 312 den =
4 24 68 108
180 16 -16 100 48 6 9 15