| Functions and CALL Routines |
Computes the number of permutations of n items that
are taken r at a time.
-
n
-
is an integer that represents the total
number of elements from which the sample is chosen.
-
r
-
is an integer value that represents the
number of chosen elements. If r is omitted, the function returns
the factorial of n.
| Restriction: |
r ![[le]](../../../../common/63294/HTML/default/images/le.gif) n |
The mathematical representation of the
PERM function is given by the following equation:
![[equation]](images/deqn153.gif)
with n ![[ge]](../../../../common/63294/HTML/default/images/ge.gif)
0, r 0, and n r.
If the expression cannot be computed, a missing value
is returned. For moderately large values, it is sometimes not possible to
compute the PERM function.
|
SAS Statements |
Results |
x=perm(5,1);
|
5
|
x=perm(5);
|
120
|
x=perm(5,2)
|
20
|
Copyright © 2011 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
