How to create an array of matrices?

Question

Goncalo Costa 2022-1-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1634550-how-to-create-an-array-of-matrices

回答： Thomas 2023-6-22

If I have 3 matrices:

A = [1 2 ; 3 4]
B = [5 6 ; 7 8]
C = [9 10 ; 11 12]

And I want to create a greater matrix with these inside like D = [A ; B ; C], that would result in something like:

D = [1 2 ; 5 6 ; 9 10

3 4 ; 7 8 ; 11 12 ]

I have tried writing something as simple as

D = [A , B , C]

But this solely puts all these matrices side by side into a single matrix, whilst I intend to keep them all separately in an array, to create a "row" of matrices...

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

the cyclist 2022-1-23

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1634550-how-to-create-an-array-of-matrices#answer_880270

编辑：the cyclist 2022-1-23

在 MATLAB Online 中打开

You could use a cell array:

A = [1 2 ; 3 4];
B = [5 6 ; 7 8];
C = [9 10 ; 11 12];
D = {A, B, C}
D = 1×3 cell array
    {2×2 double}    {2×2 double}    {2×2 double}

I think the best answer will depend on what you are planning on doing with the result afterward.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Goncalo Costa 2022-1-23

I am trying to go through each matrix in a for loop. But when I tried writing it that way, I thought that the answer you showed below meant it hadn't worked, and that therefore I couldn't use this for a for loop.

Thank you so much for your help.

请先登录，再进行评论。

Answer 2

the cyclist 2022-1-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1634550-how-to-create-an-array-of-matrices#answer_880285

在 MATLAB Online 中打开

Given your comment on my other answer, another possible solution is to stack the matrices as slices in a 3rd dimension:

A = [1 2 ; 3 4];
B = [5 6 ; 7 8];
C = [9 10 ; 11 12];
D = cat(3,A,B,C);
for ii = 1:3
    D(:,:,ii)
end
ans = 2×2
     1     2
     3     4
ans = 2×2
     5     6
     7     8
ans = 2×2
     9    10
    11    12