# all possible combinations of three vectors

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Rogier Busscher on 24 May 2017
Commented: Bruno Luong on 22 Apr 2021
I am trying to find all possible combinations of three vectors (A,B,C). For this, I tried using combvec. However, the result gets me a 1281x1 double, while i expected a matrix of 546*33*649 possibilities.
What i would like to get is:
A: 1,5,6,9,12
B: 1,2,3,4,5,6
C: 3,18,27,69,72
Ans:
1,1,3
1,1,18
1,1,27
etc.
So how do i do this?

Guillaume on 24 May 2017
One possible way, which doesn't require any toolbox:
[ca, cb, cc] = ndgrid(A, B, C);
combs = [ca(:), cb(:), cc(:)]
Bruno Luong on 22 Apr 2021
Just filter out those are not meet the constraints, or you can use this FEX to get directly the combination
allVL1(3,4,'<=')
ans =
0 0 0
0 0 1
0 1 0
1 0 0
0 0 2
0 1 1
0 2 0
1 0 1
1 1 0
2 0 0
0 0 3
0 1 2
0 2 1
0 3 0
1 0 2
1 1 1
1 2 0
2 0 1
2 1 0
3 0 0
0 0 4
0 1 3
0 2 2
0 3 1
0 4 0
1 0 3
1 1 2
1 2 1
1 3 0
2 0 2
2 1 1
2 2 0
3 0 1
3 1 0
4 0 0

Azzi Abdelmalek on 24 May 2017
A=[1,5,6,9,12]
B= [1,2,3,4,5,6]
C= [3,18,27,69,72]
[ii,jj,kk]=meshgrid(A,B,C);
ii=permute(ii,[1 3 2]);
jj=permute(jj,[2 1 3])
kk=permute(kk,[3 2 1])
out=[ii(:) jj(:) kk(:)];