Need Help in vectors combinations

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I have 2 variables (A,B) .. The first variable (A) consists of 3 vectors of size (1,9):
A(:,:,1) = [1 2 3 4 5 6 7 8 9]
A(:,:,2) = [1 4 7 2 5 8 3 6 9]
A(:,:,3) = [3 6 9 2 5 8 1 4 7]
The second variable (B) consists of 2 vectors of size (1,9):
B(:,:,1) = [11 12 13 14 15 16 17 18 19]
B(:,:,2) = [11 14 17 12 15 18 13 16 19]
How can I obtain all combinations of matrix (C) with size of (2,9) that conisits of A,B vectors for example: I want to obtain:
C(:,:,1) = [A(:,:,1) ; B(:,:,1)]
C(:,:,2) = [A(:,:,1) ; B(:,:,2)]
C(:,:,3) = [A(:,:,2) ; B(:,:,1)]
C(:,:,4) = [A(:,:,2) ; B(:,:,2)]
C(:,:,5) = [A(:,:,3) ; B(:,:,1)]
C(:,:,6) = [A(:,:,3) ; B(:,:,2)]

Accepted Answer

Stephen23
Stephen23 on 6 Jun 2017
Edited: Stephen23 on 6 Jun 2017
Use meshgrid and vertcat:
>> [Xa,Xb] = meshgrid(1:size(A,3),1:size(B,3));
>> C = vertcat(A(:,:,Xa(:)),B(:,:,Xb(:)))
C(:,:,1) =
1 2 3 4 5 6 7 8 9
11 12 13 14 15 16 17 18 19
C(:,:,2) =
1 2 3 4 5 6 7 8 9
11 14 17 12 15 18 13 16 19
C(:,:,3) =
1 4 7 2 5 8 3 6 9
11 12 13 14 15 16 17 18 19
C(:,:,4) =
1 4 7 2 5 8 3 6 9
11 14 17 12 15 18 13 16 19
C(:,:,5) =
3 6 9 2 5 8 1 4 7
11 12 13 14 15 16 17 18 19
C(:,:,6) =
3 6 9 2 5 8 1 4 7
11 14 17 12 15 18 13 16 19
  2 Comments
Mahmoud Ahmed
Mahmoud Ahmed on 7 Jun 2017
Edited: Mahmoud Ahmed on 7 Jun 2017
Actually, I have 10 variables .. One of them consists of 83 vectors .. I replace meshgrid with ndgrid .. but when I use it, MATLAB gives me error and said:
Error using ones
Maximum variable size allowed by the program is exceeded.
Error in ndgrid (line 69)
x = reshape(x(:,ones(1,prod(s))),[length(x) s]); % Expand x
What can I do ?
Walter Roberson
Walter Roberson on 7 Jun 2017
What you can do is change how you are solving your problem. You are trying to produce about 2^49 different combinations, which cannot possibly fit in memory as no released x64 architecture CPU supports more than 48 address lines.

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