How can I generate a random matrix with 0's and 1's?

Any help on generating a random matrix populated with zeros and ones, having exactly d =m/s ones per column, the locations of which are chosen uniformly from [m] without replacement. where m is the number of rows and s is from {1,...,m}. d must be an integer.

I have tried using randerr(m,n,d) but I can not get the desired output. Thanks

Answer 1

[Guillaume]

cell2mat(arrayfun(@(~) (randperm(m) <= d)', 1:n, 'UniformOutput', false))

would be one way.

[Fadugba Jeremiah]

Thanks this does what I needed but can you explain them a bit to me. Matlab documentation of cell2mat has only 1 parameter but here I'm seeing 4. thanks

[Guillaume]

cell2mat only has one argument: the output of arrayfun. arrayfun is used to create a cell array of n columns. Each column generated with (randperm(m) <= d)'. This randperm generates integers from 1 to m, shuffle them and change 1 to d to 1 and the others to 0. The whole thing is equivalent to:

output = zeros(m, n);
for column = 1:n
    output(:, column) = randperm(m) <= d;
end

If you prefer an explicit loop.

Answer 2

[Andrei Bobrov]

[~,ii] = sort(rand(m,n));
out = ii <= d;