How to combine matrices with different size but preserve elements with same value?

I have 4 columns of data which are FEM element number that share the same node (the elements are tetrahedron, hence 4 nodes) with one specific element, I want to merge them into one column so that when I select one element I can get all the elements that are connected with selected element.

for example

A= [1; 5; 8; 9], B=[1; 2; 4; 5; 7; 9]

and I want to get C=[1; 2; 4; 5; 7; 8; 9]

Is this possible?

Answer 1

[Jan]

Do you mean union?

A = [1; 5; 8; 9];
B = [1; 2; 4; 5; 7; 9];
C = union(A, B)

C = 7×1

1 2 4 5 7 8 9

[Steven Lai]

THANK YOU SO MUCH

Answer 2

[Fangjun Jiang]

unique([A;B])?

Answer 3

[Steven Lord]

None of A, B, or C have four columns like you stated you had.

You didn't indicate how you generated C from A and B, but one way to do so:

A= [1; 5; 8; 9];
B=[1; 2; 4; 5; 7; 9];
C = union(A, B)

C = 7×1

1 2 4 5 7 8 9

whos A B C % 1 column each

  Name      Size            Bytes  Class     Attributes

  A         4x1                32  double              
  B         6x1                48  double              
  C         7x1                56  double              

[Steven Lai]

A B and C are just example, I just want to make sure I can simplify my problem enough.

Union is perfect, even though I need to do it three times because it can't have more than 2 argument in it.

Thank you!