Growing Diagonal Matrix Problem

I am trying to create a diagonal matrix that can grow a # of rows and # of collumns. These collumns can be from a range of 10 to 100000 to infinite but must maintain a pattern.
For simplicity I am using a 9x9 Matrix. It seems like it is repeating 3 matrics over and over.
1 - Diagonal
1 - Ones Diagonal
1 - Zeros
A B 0 1 0 0 0 0 0
B A B 0 1 0 0 0 0
0 B A 0 0 1 0 0 0
1 0 0 A B 0 1 0 0
0 1 0 B A B 0 1 0
0 0 1 0 B A 0 0 1
0 0 0 1 0 0 A B 0
0 0 0 0 1 0 B A B
0 0 0 0 0 1 0 B A
I am having a hard time trying to seeing how to write this.

回答(1 个)

A=3; B=4;
M=[A B 0; B A B; 0 B A];
n=3;
e = ones(n,1);
Q = spdiags([e 0*e e],-1:1,n,n);
%Q=toeplitz(sparse([0,1,zeros(1,n-2)]));
result =kron(speye(n),M)+kron(Q,eye(3));
full(result)
ans = 9×9
3 4 0 1 0 0 0 0 0 4 3 4 0 1 0 0 0 0 0 4 3 0 0 1 0 0 0 1 0 0 3 4 0 1 0 0 0 1 0 4 3 4 0 1 0 0 0 1 0 4 3 0 0 1 0 0 0 1 0 0 3 4 0 0 0 0 0 1 0 4 3 4 0 0 0 0 0 1 0 4 3

4 个评论

I need the big matix to be changable, like if the 9x9 can be change to a 100x100. The 9x9 is just an example.
I know it's just an example. So is the value of n=3 in my code.
Here is my next problem, what is it need to be changed to 8x8? But keep everything the same except the last row and collumn?
If you mean you want to remove the last row and column, then,
result(:,end)=[]; %remove last column
result(end,:)=[]; %remove last row

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提问:

2021-3-23

编辑:

2021-3-24

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