Basic syntax:
---------------                                         
permin x, k(#)
                        
Description     
-----------                                     
permin generates `k' possible permutations from a set of `n' objects, where `k'
>  is not greater than 5 (2 =< k <= 5).         
The program supports both numeric and string variables.

permutation: [n! / (n-k)!]                      

n: total number of observations                         
k: permutations
                                                
                                                
(original)            k permutations (k=2, n=3)                 
  +----+              +-----+-----+
  | x  |    ===>      | x_1 | x_2 |
  +----+              +-----+-----+
  | A  |              |  A  |  B  |
  | B  |              |  A  |  C  |
  | C  |              |  B  |  A  |
  +----+              |  B  |  C  |
                      |  C  |  A  |
                      |  C  |  B  |
                      +-----+-----+
                                                
        
        
(original)             k permutations(k=3, n=3) 
  +----+              +-----+-----+-----+   
  | x  |    ===>      | x_1 | x_2 | x_3 |
  +----+              +-----+-----+-----+
  | A  |              |  A  |  B  |  C  |
  | B  |              |  A  |  C  |  B  |
  | C  |              |  B  |  A  |  C  |
  +----+              |  B  |  C  |  A  |
                            |  C  |  A  |  B  |
                      |  C  |  B  |  A  |
                      +-----+-----+-----+


Examples:
---------
permin x, k(2)
permin x, k(3)          
permin x, k(4)                                          
permin x, k(5)                                          
                                                
                        
Author                                          
Muhammad Rashid Ansari                                          
INSEAD Business School                                          
1 Ayer Rajah Avenue, Singapore 138676                                          
>  
rashid.ansari@insead.edu