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Matrix Manipulations - How to achieve these specific forms?

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Mathias Dirksmeier
Mathias Dirksmeier 2018-9-20
评论： Mathias Dirksmeier 2018-9-20
Dear Community,
I am struggling to achieve two distinct forms of matrices.
1) I want to build a matrix with the following form and dimensions of [8760 x 2*8760]
(1 1 0 0 0 0 ...
0 0 1 1 0 0 ...
0 0 0 0 1 1 ...
...)
2) I want to build a matrix with the following form and dimensions of [2*8760 x 2*8760]
(0 0 0 0 0 0 ...
5 8 0 0 0 0 ...
0 0 0 0 0 0 ...
5 8 5 8 0 0 ...
...)
I just can't make that work, also I am fairly new to Matlab. I really hope somebody can see a solution here.
Thanks a lot, Mathias

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采纳的回答

Jos (10584)
Jos (10584) 2018-9-20
Bruno's and KSSV's answers do not create the matrices you asked for, or am I mistaken? Anyways, here are my suggestions:
N = 4 ; % small example, rather than N=8760
M1 = kron(eye(N), [1 1])
% 1 1 0 0 0 0 ...
% 0 0 1 1 0 0 ...
% 0 0 0 0 1 1 ...
% ...
M2 = kron(tril(ones(N)), [0 0 ; 5 8])
% 0 0 0 0 0 ...
% 5 8 0 0 0 ...
% 0 0 0 0 0 ...
% 5 8 5 8 0 ...
% ...
  2 个评论
Bruno Luong
Bruno Luong 2018-9-20
I'm not 100% convinced since in the example of (2) given by OP we can't see a 2x2 block far below the diagonal, so there is still a confusion whereas the lower-diagonal or 2-diagonal by block is needed.
In anycase he/she gets the receipt to build the matrix.

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更多回答（2 个）

Bruno Luong
Bruno Luong 2018-9-20
>> A=diag(ones(1,5),0)+diag(ones(1,4),-1)
A =
1 0 0 0 0
1 1 0 0 0
0 1 1 0 0
0 0 1 1 0
0 0 0 1 1
>> kron(A,[2 3; 5 8])
ans =
2 3 0 0 0 0 0 0 0 0
5 8 0 0 0 0 0 0 0 0
2 3 2 3 0 0 0 0 0 0
5 8 5 8 0 0 0 0 0 0
0 0 2 3 2 3 0 0 0 0
0 0 5 8 5 8 0 0 0 0
0 0 0 0 2 3 2 3 0 0
0 0 0 0 5 8 5 8 0 0
0 0 0 0 0 0 2 3 2 3
0 0 0 0 0 0 5 8 5 8
>>
  4 个评论
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Bruno Luong
Bruno Luong 2018-9-20
编辑：Bruno Luong 2018-9-20
The first question is easily extrapolated (I did not give the answer for the first question)
FirstQuestionMat =diag(ones(1,5),0)+diag(ones(1,4),+1)
If you claim my solution for the second quetion is good, then Jos's answer is not, and vice-versa.
Look again the results, and be clear in you mind.
Better learn the technique rather than take the answer as it is.

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KSSV
KSSV 2018-9-20
Read about diag
N = 10 ;
A = diag(ones(N,1))+diag(ones(N-1,1),-1) ;

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