how can i get all subsets from a matrix

i have a matrix for example x=

[1 2 3 6 7;4 5 6 8 9;8 7 6 3 1;5 6 7 9 1;6 4 2 9 6]

i want ta take first colomn with the scond and make it matrix from order 5×2 then col:1,3 and col:1,4, col:1,5 then 3 columns 1,2,3 and 1 2 4 and 1 2 4 etc.. these submatcese are 2^5= 32 matrix any help?

Answer 1

[Guillaume]

m = [1 2 3 6 7;4 5 6 8 9;8 7 6 3 1;5 6 7 9 1;6 4 2 9 6];
out = cell(2^size(m, 2), 1);
outrow = 1;
for numcols = 0:size(m, 2)
   colcombs = nchoosek(1:size(m, 2), numcols);
   for c = 1:size(colcombs, 1)
       out{outrow} = m(:, colcombs(c, :));
       outrow = outrow + 1;
   end
end

Or using cellfun / arrayfun:

m = [1 2 3 6 7;4 5 6 8 9;8 7 6 3 1;5 6 7 9 1;6 4 2 9 6];
out = arrayfun(@(numcols) cellfun(@(colcomb) m(:, colcomb), num2cell(nchoosek(1:size(m, 2), numcols), 2), 'UniformOutput', false), 0:size(m, 2), 'UniformOutput', false);
out = vertcat(out{:});