M = {[1,2,3], [4,5,6],[7,8,9];
[10,11],[12,13],[14,15];
[16,17,18,19,20],[21,22,23,24],[25,26,27,28]};
res = {allcomb(M{1,1:3}, M{2,1:3}, M{3,1:3})};
res = permute(reshape(res{:}',3,3,[]),[2 1 3]);
The order of the results is a bit different then you wanted, but always only one value is changed:
>> res(:,:,1:5)
ans(:,:,1) =
1 4 7
10 12 14
16 21 25
ans(:,:,2) =
1 4 7
10 12 14
16 21 26
ans(:,:,3) =
1 4 7
10 12 14
16 21 27
ans(:,:,4) =
1 4 7
10 12 14
16 21 28
ans(:,:,5) =
1 4 7
10 12 14
16 22 25
