How can I create a random matrix without repeating any value between column

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I get two columns with the same value when I generate the matrix. For example,
1 1 3 2 4
4 4 1 4 3
2 2 2 3 1
3 3 4 1 2
I want to get something like the 10 combinations from the 24 combinations(4 factorial).
1 1 3 2 4 1 2 4 3 2
2 4 1 4 3 3 3 1 2 1
3 2 2 3 1 4 1 3 4 3
4 3 4 1 2 2 4 2 1 4
I need the matrix to form the chromosomes for GA.
  3 Comments
Dyuman Joshi
Dyuman Joshi on 23 May 2023
As Steven mentions, it's not clear what is the pattern you are following to obtain the output.
From a cursory glance, it can be observed from the output that the 1st column is sorted and the 6th column corresponds to the indices of the sorted values of the 1st column. But the it's not clear what's the logic behind the columns 7-10.
Wan
Wan on 28 May 2023
Sorry for not making my question clear. There are no special rules to follow. So long as the matrix generates non-repeated combinations from the 24 combinations, then it is good enough. It does not need to be exactly like the second matrix. The second matrix is just an example.

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Accepted Answer

David Goodmanson
David Goodmanson on 24 May 2023
Edited: David Goodmanson on 24 May 2023
Hello Wan,
all columns contain 1 through 4, and all columns are different
a = perms(1:4) % all 24 permutations of 1:4
ind = randperm(24);
ind = ind(1:10) % an index of 10 random integers from 1 to 24, no repeats
b = a(ind,:)' % 10 random choices from the rows of a,
% then transpose to get 4x10 matrix

More Answers (1)

Sulaymon Eshkabilov
Sulaymon Eshkabilov on 23 May 2023
You can use reshape(), randperm(), numel(), size() fcns to create ramdom swaps of the already existing matrix elements:
A1 = [1 1 3 2 4;
4 4 1 4 3;
2 2 2 3 1;
3 3 4 1 2];
A_new = [reshape(A1(randperm(numel(A1))), size(A1)), reshape(A1(randperm(numel(A1))), size(A1))]
A_new = 4×10
3 4 4 3 2 2 2 3 4 2 1 3 4 2 1 1 1 2 1 4 3 4 4 1 2 1 4 4 3 3 1 3 2 1 2 3 3 4 1 2

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