查看完整版本 : maxima在线性代数中的应用


study
2006-08-12 23:10

定义矩阵,向量:

(%i1)A:matrix([1,2,3],[-2,8,3],[1,4,9]);

(%o1)[1 2 3]

         [-2 8 3]

         [1 4 9]

(%i2)v:[2,3,5];

(%o2)[2 3 5]

把行向量变为列向量:

(%i3)v:transpose([2,3,5]);

(%o3)[2]

         [3]

         [5]

(%i4)v:matrix([2],[3],[5]);

(%o4)[2]

         [3]

         [5]




此帖由 study 在 2006-08-13 18:53 进行编辑...

study
2006-08-13 18:51

矩陣的表示和截取:

定义符号矩阵:

(%i1)A:matrix([a[1,1],a[1,2]],[a[2,1],a[2,2]]);

(%o1)[a1,1   a1,2]

         [a2,1   a2,2]

C为常数:

(%i2)C*A;

(%o2)[a1,1C   a1,2C]

         [a2,1C   a2,2C]

定义常数矩阵:

(%i3)B:matrix([1,2,3],[-2,8,3],[1,4,9]);

(%o3)[1 2 3]

         [-2 8 3]

         [1 4 9]

提取矩阵B中1行元素:

(%i4)row(B,1);

(%o4)[1 2 3]

提取矩阵B中2列元素:

(%i5)col(B,2);

(%o5)[2]

         [8]

         [4]

提取矩阵B中2行3列元素:

(%i6)B[2,3];

(%o6)3


study
2006-08-16 23:04
矩阵的四则运算:
(%i1)A:matrix([9,4,2],[2,9,3],[0,1,4]);

(%o1)[9 4 2]

[2 9 3]
[0 1 4]
(%i2)B:matrix([2,8,1],[8,3,4],[6,4,0]);
(%o2)[2 8 1]

[8 3 4]
[6 4 0]
(%i3)5*A;
(%o3)[45 20 10]

[10 45 15]
[0 5 20]
(%i4)A+B;
(%o4)[11 12 3]

[10 12 7]
[6 5 4]
(%i5)A-B;
(%o5)[7 -4 1]

[-6 6 -1]
[-6 -3 4]
(%i6)A.B; 矩阵的乘
(%o6)[62 92 25]

[94 55 38]
[32 19 4 ]
(%i7)A*B; 对应元素相乘
(%o7)[18 32 2 ]

[16 27 12]
[0 4 0 ]




















此帖由 study 在 2006-08-18 23:38 进行编辑...

study
2006-08-18 23:13
矩阵相关函数:
(%i1)A:matrix([1,2,3],[-2,8,3],[1,4,9]);

(%o1) [ 1 2 3]

[-2 8 3]
[ 1 4 9]
(%i2)transpose(A); 矩阵转置
(%o2)[1 -2 1]

[2 8 4]
[3 3 9]
(%i3)determinant(A); 矩阵行列式
(%o3)54
(%i4)adjoint(A); 伴随矩阵

(%o4)[60 -6 -18]

[21 6 -9 ]
[-16 -2 12]
(%i5)invert(A); 反矩阵
(%o5)[10/9 -1/9 -1/3 ]

[7/18 1/9 -1/6 ]
[-8/27 -1/27 2/9]
(%i6)echelon(A); 梯形矩阵
(%o6)[1 2 3 ]

[0 1 3/4]
[0 0 1 ]
(%i7)diagmatrix(4,5);4*4阶对角矩阵,对角元素为5
(%o7)[5 0 0 0]
[0 5 0 0]
[0 0 5 0]
[0 0 0 5]
(%i8)m:[2*x+y+z=7,x-4*y+3*z=2,3*x+2*y+2*z=13]$
(%i9)augcoefmatrix(m,[x,y,z]);线性方程组系数矩阵
(%o9)[2 1 1 -7 ]
[1 -4 3 -2 ]
[3 2 2 -13]
(%i10)B:matrix([4,0,1],[2,3,2],[1,0,4]);
(%o10)[4 0 1]
[2 3 2]
[1 0 4]
(%i11)load("nchrpl")$加载相关软件包,调用函数mattrace()
(%i12)mattrace(B);求矩阵B的对角元素之和
(%o12)11
(%i13)eigenvalues(B);矩阵B的特征值为[5,3]
(%o13)[[5,3],[1,2]]
(%i14)eigenvectors(B);
矩阵B的特征向量,5对应[1,2,1],3对应[1,0,-1],[0,1,0]
(%o14)[[[5,3],[1,2]],[1,2,1],[1,0,-1],[0,1,0]]
(%i15)determinant(B-digamatrix(length(B),x));
求矩阵B特征多项式
(%o15)x+(3-x)(4-x)2-3
(%i16)expand(%o15); 展开
(%o16)-x3+11x2-39x+45

(%i17)eq1:x+2*y+3*z=6$
(%i18)eq2:2*x-3*y+2*z=14$
(%i19)eq3:3*x+y-z=-2$
(%i20)solve([eq1,eq2,eq3],[x,y,z]);解线性方程组
(%o20)[[x=1,y=-2,z=3]]












































































































































此帖由 study 在 2006-09-27 23:03 进行编辑...

study
2006-08-27 23:51
矩阵定义:
(%i1) n: 3$
(%i2) m: entermatrix (n, n)$

Is the matrix 1. Diagonal 2. Symmetric 3. Antisymmetric 4. General
Answer 1, 2, 3 or 4 : 1
选择1对角矩阵;2符号矩阵;3反符号矩阵;4一般矩阵
Row 1 Column 1: (a+b)^n$
Row 2 Column 2: (a+b)^(n+1)$
Row 3 Column 3: (a+b)^(n+2)$

Matrix entered.
(%i3) m;
(%o3)
[ (b + a)^3 0 0 ]
[ 0 (b + a)^4 0 ]
[ 0 0 (b + a)^5 ]
(%i4)F[i,j]:=1/(i+j-1)$
(%i5)genmatrix(F,3,3);
由函数产生矩阵
(%o5)[1 1/2 1/3]
[1/2 1/3 1/4]
[1/3 1/4 1/5]































此帖由 study 在 2006-08-28 00:27 进行编辑...