Basic syntax:
---------------
combin x, k(#)
Description
-----------
combin generates `k' unique combinations from a set of `n' objects, where `k' i
> s not greater than 5 (2 =< k <= 5).
Program first arranges `k' possible permutations and then retains unique combin
> ations. It supports both string and numeric variables.
combination: [n! / k!(n-k)!]
n: total number of observations
k: unique combinations
(original) k unique combinations (k=2, n=4)
+----+ +-----+-----+
| x | ===> | x_1 | x_2 |
+----+ +-----+-----+
| A | | A | B |
| B | | A | C |
| C | | A | D |
| D | | B | C |
+----+ | B | D |
| C | D |
+-----+-----+
(original) k unique combinations (k=3, n=4)
+----+ +-----+-----+-----+
| x | ===> | x_1 | x_2 | x_3 |
+----+ +-----+-----+-----+
| A | | A | B | C |
| B | | A | B | D |
| C | | A | C | D |
| D | | B | C | D |
+----+ +-----+-----+-----+
Examples:
---------
combin x, k(2)
combin x, k(3)
combin x, k(4)
combin x, k(5)
Author
Muhammad Rashid Ansari
INSEAD Business School
1 Ayer Rajah Avenue, Singapore 138676
>
rashid.ansari@insead.edu