random

I have a Matrix as follows

 x   = [1     2     3     4     5
         6     7     8     9    10
        11    12    13    14    15
        16    17    18    19    20];

I want to generate a matrix from it that will be for example 100 combination of each element but for example for the first iteration, from first colum only one of them select then from the second as well then from the third as well and untill the end

so I may have like this

x   = [ 6 2 18 4 20 
16 17 3 4 10 
and so on

Answer 1

[Andrei Bobrov]

x   = [1     2     3     4     5
6     7     8     9    10
11    12    13    14    15
16    17    18    19    20];

EDIT after Mohammad's coment

[m,n] = size(x);
df = bsxfun(@plus,fullfact(m*ones(1,n)),(0:n-1)*m);
k = randperm(size(df,1));
out = x(df(k(1:min(100,numel(k))),:));

OR

[m,n] = size(x);
xc = mat2cell(x,m,ones(n,1));
cc = cell(1,n);
[cc{:}] = ndgrid(xc{:});
k = randperm(numel(cc{1}));
out =  cell2mat(cellfun(@(x)x(k(1:min(100,numel(k)))'),cc,'un',0));

[Niki]

does not work,

try it on this

data =rand (4,2)

[Niki]

I want to have something lets say, number of permutation , can you also tell me what should I do with that?

for example I want to have only 100 generated row

more or less

[Andrei Bobrov]

full number of permutation for matricies with size m x n : N = m^n