>> A=zeros(3,8)
A =
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
>> B=eye(size(A))
B =
1 0 0 0 0 0 0 0
0 1 0 0 0 0 0 0
0 0 1 0 0 0 0 0
>> n = 6; % 定义变量n并赋值为10
A = rand(n)% 生成一个n*n的随机矩阵
A =
0.3786 0.5502 0.2305 0.4357 0.9797 0.2622
0.8116 0.6225 0.8443 0.3111 0.4389 0.6028
0.5328 0.5870 0.1948 0.9234 0.1111 0.7112
0.3507 0.2077 0.2259 0.4302 0.2581 0.2217
0.9390 0.3012 0.1707 0.1848 0.4087 0.1174
0.8759 0.4709 0.2277 0.9049 0.5949 0.2967
>> C=[1,2,3];V=diag(C)
V =
1 0 0
0 2 0
0 0 3
>> V1=diag(V)
V1 =
1
2
3
>> %生成主对角线上第2条对角线为C的矩阵
>> V2=diag(C,2)
V2 =
0 0 1 0 0
0 0 0 2 0
0 0 0 0 3
0 0 0 0 0
0 0 0 0 0
>> V3=diag(C,-1)
V3 =
0 0 0 0
1 0 0 0
0 2 0 0
0 0 3 0 
>> H=hankel(C)%后面都为0
H =
1 2 3
2 3 0
3 0 0
范德蒙矩阵
>> P=[2 0 4 5 6]; A=compan(P)
A =
0 -2.0000 -2.5000 -3.0000
1.0000 0 0 0
0 1.0000 0 0
0 0 1.0000 0 
>> A=sym('a%d%d',4)
A =
[a11, a12, a13, a14]
[a21, a22, a23, a24]
[a31, a32, a33, a34]
[a41, a42, a43, a44]
>> B=sym('a%d%d',[4,2])
B =
[a11, a12]
[a21, a22]
[a31, a32]
[a41, a42]
>> C=sym('f%d%d',[4,4])
C =
[f11, f12, f13, f14]
[f21, f22, f23, f24]
[f31, f32, f33, f34]
[f41, f42, f43, f44] 
>> A=[16 2 3 13; 5 11 10 8; 9 7 6 12; 4 14 15 1]; det(A)%数值解，不一定精准
ans =
5.1337e-13
>> det(sym(A))%符号矩阵
ans =
0
>> A=sym('a%d%d',[4,4]),det(A)
A =
[a11, a12, a13, a14]
[a21, a22, a23, a24]
[a31, a32, a33, a34]
[a41, a42, a43, a44]
ans =
a11*a22*a33*a44 - a11*a22*a34*a43 - a11*a23*a32*a44 + a11*a23*a34*a42 + a11*a24*a32*a43 - a11*a24*a33*a42 - a12*a21*a33*a44 + a12*a21*a34*a43 + a12*a23*a31*a44 - a12*a23*a34*a41 - a12*a24*a31*a43 + a12*a24*a33*a41 + a13*a21*a32*a44 - a13*a21*a34*a42 - a13*a22*a31*a44 + a13*a22*a34*a41 + a13*a24*a31*a42 - a13*a24*a32*a41 - a14*a21*a32*a43 + a14*a21*a33*a42 + a14*a22*a31*a43 - a14*a22*a33*a41 - a14*a23*a31*a42 + a14*a23*a32*a41
>> i=2; j=3; B=A; B(i,:)=[]; B(:,j)=[]; A23=(-1)^(i+j)*det(B)
A23 =
a11*a34*a42 - a11*a32*a44 + a12*a31*a44 - a12*a34*a41 - a14*a31*a42 + a14*a32*a41删除B的第i行，删除B的第j列
>> syms a23;A23_1=simplify((det(A)-subs(det(A),a23,0))/a23)
A23_1 =
a11*a34*a42 - a11*a32*a44 + a12*a31*a44 - a12*a34*a41 - a14*a31*a42 + a14*a32*a41 
