How to form a matrix from a given matrix?

I have a matrix as

A=[1 3 
  5 4]

I want to form a matrix with all possible pairs for example

B=[1 3 4
   1 3 5
   3 4 5]

where, B is obtained from A with all elements of A and formed a 3 collumn matrix.

please please help me....

Answer 1

[Guillaume]

Use nchoosek:

 A = [1 3; 5 4]; %Note that it does not make sense to have A as a matrix. 
 %A = [1 3 4 5] would make more sense.
 B = nchoosek(A(:), 3)