How can I pick certain element from each row of an array ?

I already have an array CF [ 1 2 3; 2 3 4]

How can I create an for loop that give me an array CE [ 1 2; 2 3; 3 1; 3 4; 4 2] ?

Each row of CF represent a face of an triangle. Each row of CE represents the edges of the face.

Thank you

[Walter Roberson]

I cannot tell what your rule is for constructing the edges?

Answer 1

[Fabio Freschi]

I see that the edges shared by two triangles are not duplicated. To check for this case I sorted the nodes and the edges. Let me know if it is ok:

CF = [ 1 2 3; 2 3 4];

% sorted nodes (always increasing node)
CFs = sort(CF,2);

% remove repetitions and get edges
CE = unique(reshape(CF(:,[1 2 2 3 1 3]).',2,3*size(CF,1)).','rows')

[kiet tran]

Thank you Fabio!