Shuffle matrix elements

Hey guys, I want to shuffle a 3x3 matrix (which consist elements within 1:9 unrepeated). So that I have written a very strange code.

>>X=perms(1:9);

Execute above line once.

Then execute below line how many shuffled matrices you want.

>>SMx=reshape(X(randi(size(X,1)),:),3,3)

Is there any better way to do this?

Answer 1

[Jan]

SMx = reshape(randperm(9), 3, 3);

If you have Matlab 2011b, use "randperm(9, 9)" instead: It uses the Fisher-Yates-Shuffle, which is much faster. And if you struggle with large arrays, this is even faster: FEX: Shuffle.

Answer 2

[Fangjun Jiang]

I believe it means to be randperm(), not perms().

OrigData=magic(3);
X=randperm(numel(OrigData));

ShuffledData=reshape(OrigData(X),size(OrigData))

[Jan]

PERMS is correct: Raviteja produces *all* permutations at first and chooses a specific one afterwards. This needs a lot of memory...

Answer 3

[Amgad Mohsen]

A function file as I did with out randperm()

function W = randomize(A)
[m,n] = size(A);
E = A(:);
W(1) = E(1);
E(1) =[];
N = m*n;
while length(E) > 0
    K = length(W);
    RandInd = randi(length(E),1);
    for j = 1: K 
       P(j) =  E(RandInd) ~= W(j); 
    end
    if all(P) 
    W =[W,E(RandInd)];
    E(RandInd) =[];
    end
end  
W = reshape(W,m,n);