Full factorial

It gives full factorial design matgrix of any levels(more than 2) of any variables (minimum 2)

This script is similar to fullfact, however instead of number of levels, value of levels are required as input
usage: des_mat = full_fact([-1 1],[100 200 300],[1:4]);

arguments: (input)
x1,x2, x3- variable levels either in row or column vector. These are
not number of levels but the levels itself

arguments: (output)
des_mat - mxn m= total number of designs (product of all levels) and
n is number of variables
The first column shows all the first variable levels, second
column shows second variable levels and so on.

Example usage:
x1=[-1 1];x2=[100:100:300];
des_mat = full_fact(x1,x2) % OR
des_mat = full_fact([-1 1],[100:100:300])
des_mat =
-1 100
-1 200
-1 300
1 100
1 200
1 300