How could I randomly split the columns of a matrix into 3 matrices with equal number of columns?

Hi everyone,

I would like to ask if there is a way to split a matrix A, with dimensions (100 x 12) into three sub-matrices with dimensions 100 x 4 each. The splitting should be random. For example, sub-matrix B = [A(:,1) A(:,5) A(:,6) A(:,11)], but the elements of the B cannot be included in any of the other sub-matrices. For instance, a potential outcome of sub-matrix C could be C=[A(:,3) A(:,8) A(:,10) A(:,12)] and D=[A(:,2) A(:,4) A(:,7) A(:,9)]. As an extension of the question, ideally, I would like to get different sub-matrices every time I iterate the experiment.

Answer 1

[Matt J]

Ar=A(:,randperm(12));

submatrix{1}=Ar(:,1:4);
submatrix{2}=Ar(:,5:8);
submatrix{3}=Ar(:,9:12);

[gsourop]

The submatrix should be submatrix{3}=Ar(:,9:12), right?

[Matt J]

Yes, you're right. I fixed it.