清空筛选条件
清空筛选条件

Calculating a matrix from other matrices

1 次查看（过去 30 天）
Saleh Msaddi
Saleh Msaddi 2021-2-15
编辑： Matt J 2021-2-15
How can I write the following matrix?
M = [C*B;
C*A*B + C*B;
C*A^2*B + C*A*B + C*B;
.
.
.
C*A^(N-1)*B + C*A^(N-2)*B + ... + C*B];
A, B, and C are 2D arrays with size(A)=(n,n), size(B)=(n,p), and size(C)=(q,n). N is a positive integer.
  1 个评论
Walter Roberson
Walter Roberson 2021-2-15
I posted code for the 2D version of this a couple of years ago, where the values were being copied down the diagonals.
Unfortunately it has been far too long for me to recall the key words that would needed to find it within my other posts :(

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

Matt J
Matt J 2021-2-15
Q=eye(n);
Mcell=cell(n,1);
for i=1:N
Mcell{i}=C*Q*B;
Q=A*Q+Q;
end
M=cell2mat(Mcell);
  2 个评论
Saleh Msaddi
Saleh Msaddi 2021-2-15
Thanks @Matt J for your answer. However, I tried to execute the code and compre the results but they are not the same (only the first 2 rows are the same)
N = 4;
A = rand(4);
B = rand(4,1);
C = rand(1,4);
[n,p] = size(B);
R = [C*B;
C*A*B + C*B;
C*A^2*B + C*A*B + C*B;
C*A^3*B + C*A^2*B + C*A*B + C*B];
Q=eye(n);
Mcell=cell(n,1);
for i=1:N
Mcell{i}=C*Q*B;
Q=A*Q+Q;
end
M=cell2mat(Mcell);
R == M
Matt J
Matt J 2021-2-15
编辑：Matt J 2021-2-15
Ran in:
Sorry, it should be
N = 4;
A = rand(4);
B = rand(4,1);
C = rand(1,4);
[n,p] = size(B);
R = [C*B;
C*A*B + C*B;
C*A^2*B + C*A*B + C*B;
C*A^3*B + C*A^2*B + C*A*B + C*B];
[Q,Q0]=deal(eye(n));
Mcell=cell(n,1);
for i=1:N
Mcell{i}=C*Q*B;
Q=A*Q+Q0;
end
M=cell2mat(Mcell);
difference=norm(R-M)
difference = 1.8310e-15

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Matrices and Arrays 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by