How to produce a matrix with the following conditions?

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How to produce a matrix which size is 7*7 and contains all possible single locations of a certain value and the rest of the column's values are 1. For example : The value is 0.4 and I want to produce seven columns of different single locations of 0.4 and the other values are 1 such as: [0.4 1 1 1 1 1 1; 1 0.4 1 1 1 1 1; 1 1 0.4 1 1 1 1; 1 1 1 0.4 1 1 1; 1 1 1 1 0.4 1 1; 1 1 1 1 1 0.4 1; 1 1 1 1 1 1 0.4]

Accepted Answer

Sam Chak
Sam Chak on 13 Sep 2022
Hi @M
Maybe like this?
M = ones(7)
M = 7×7
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
I = eye(7)
I = 7×7
1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1
v = 0.4;
u = repelem(v, 7)
u = 1×7
0.4000 0.4000 0.4000 0.4000 0.4000 0.4000 0.4000
D = diag(u)
D = 7×7
0.4000 0 0 0 0 0 0 0 0.4000 0 0 0 0 0 0 0 0.4000 0 0 0 0 0 0 0 0.4000 0 0 0 0 0 0 0 0.4000 0 0 0 0 0 0 0 0.4000 0 0 0 0 0 0 0 0.4000
Solution = M - I + D
Solution = 7×7
0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000
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More Answers (1)

Walter Roberson
Walter Roberson on 15 Sep 2022
M = ones(7);
C = M;
C(logical(eye(7))) = 0.4
C = 7×7
0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000
%or
M = ones(7);
C = M;
C(1:size(C,1)+1:end) = 0.4
C = 7×7
0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000
%or
M = ones(7);
C = M - 0.6 * eye(size(M))
C = 7×7
0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 0.4000

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