Date: Nov 26, 2012 11:12 PM
Author: Jerry
Subject: nchoosek all pairwise combinations


There is a vector

A=['a', 'b', 'c', 'd','e']

I would like to make a square matrix of all paiwise interactions of this vector:

a b c d e
a aa ba ca da ea
b ab bb cb db eb
c ac bc cc dc ec
d ad bd cd dd ed
e ae bd ce de ee

However, nchoosek allow me to create only half of this matrix. Is there any function to make all these possible interactions within "A"?