Changing matrix column order

An having difficulty expressing the result I would like, but it is shown in the example below. How can I change the order of matrix A's columns so that they are like matrix B, regardless of the data values.

A =

     1     2     3    11    22    33   111   222   333
     1     2     3    11    22    33   111   222   333
     1     2     3    11    22    33   111   222   333
     1     2     3    11    22    33   111   222   333

B =

     1    11   111     2    22   222     3    33   333
     1    11   111     2    22   222     3    33   333
     1    11   111     2    22   222     3    33   333

Answer 1

[Walter Roberson]

reshape(permute(reshape(A,size(A,1),3,[]),[1 3 2]),size(A,1),[])

[Penny Ibil]

Amazing. Thank you

[Penny Ibil]

Can you explain what the [1 3 2] as the dimorder means?

[Walter Roberson]

permute(X, [1 3 2]) means that dimension 1 should stay the same, and what was dimension 3 should become the new dimension 2, and that what was dimension 2 should become the new third dimension.

permute() is a generalization of transpose(). It moves elements around.

for I = 1 : size(A, 1)
    for J = 1 : size(A,2)
        for K = 1 : size(A,3);
            output(I, K, J) = A(I, J, K);
        end
    end
end

Answer 2

[Ameer Hamza]

For this particular example

A = ...
    [1     2     3    11    22    33   111   222   333
     1     2     3    11    22    33   111   222   333
     1     2     3    11    22    33   111   222   333
     1     2     3    11    22    33   111   222   333];

idx = [1 4 7 2 5 8 3 6 9];
B = A(:, idx);

Result

>> B
B =
     1    11   111     2    22   222     3    33   333
     1    11   111     2    22   222     3    33   333
     1    11   111     2    22   222     3    33   333
     1    11   111     2    22   222     3    33   333

Is there a general rule that can be expressed mathematically?

[Penny Ibil]

I want to say that it has something to do with getting the modulo, but I can't quite see it:

>> mod(1:length(A),3)

ans =

     1     2     0     1     2     0     1     2     0

[Ameer Hamza]

Do you want to move all columns start with 1 to the left in increasing order, then columns of 2, then 3, so on. Something like this?