Non-repeating selection from sets

A is 1 by a matrix, B 1 by b, and C 1 by c. D is supposed to be the set of all non-repeating selection of respectively A, B, and C columns. What would be the most economical code of triples extraction? Thanks.

Answer 1

[Dyuman Joshi]

%Random data
A = 1:3;
B = 1:4;
C = 1:5;

D = {A, B, C}

D = 1×3 cell array
    {[1 2 3]}    {[1 2 3 4]}    {[1 2 3 4 5]}

n = numel(D);

%Preallocate
out = cell(1, n);

%Reverse order to get the lexicographical order when concatenating
[out{end:-1:1}] = ndgrid(D{end:-1:1});

%Concatenate and reshape the data corresponding to number of vectors
out = reshape(cat(n,out{:}),[],n);
disp(out)

     1     1     1
     1     1     2
     1     1     3
     1     1     4
     1     1     5
     1     2     1
     1     2     2
     1     2     3
     1     2     4
     1     2     5
     1     3     1
     1     3     2
     1     3     3
     1     3     4
     1     3     5
     1     4     1
     1     4     2
     1     4     3
     1     4     4
     1     4     5
     2     1     1
     2     1     2
     2     1     3
     2     1     4
     2     1     5
     2     2     1
     2     2     2
     2     2     3
     2     2     4
     2     2     5
     2     3     1
     2     3     2
     2     3     3
     2     3     4
     2     3     5
     2     4     1
     2     4     2
     2     4     3
     2     4     4
     2     4     5
     3     1     1
     3     1     2
     3     1     3
     3     1     4
     3     1     5
     3     2     1
     3     2     2
     3     2     3
     3     2     4
     3     2     5
     3     3     1
     3     3     2
     3     3     3
     3     3     4
     3     3     5
     3     4     1
     3     4     2
     3     4     3
     3     4     4
     3     4     5

[Dyuman Joshi]

What is the expected output in this case?

Is the one given by this code not the one you want?

A = [2 3 4]; 
B = 5; 
C = [6 8];

D = {A, B, C}

D = 1×3 cell array
    {[2 3 4]}    {[5]}    {[6 8]}

n = numel(D);
%Preallocate
out = cell(1, n);

%Reverse order to get the lexicographical order when concatenating
[out{end:-1:1}] = ndgrid(D{end:-1:1});

%Concatenate and reshape the data corresponding to number of vectors
out = reshape(cat(n,out{:}),[],n);
disp(out)

     2     5     6
     2     5     8
     3     5     6
     3     5     8
     4     5     6
     4     5     8

[Dyuman Joshi]

Are using the same code as above?

Please share the full error message i.e. all of the red text.

[Amir Mahmoudi]

Your code is working precisely. I had made a minor mistake. Thanks.

[Amir Mahmoudi]

I deleted my previous comments.