PERM Function

Computes the number of permutations of n items taken r at a time

Category: Mathematical

Syntax

PERM ( n <, r >)

Arguments

n

• is an integer that represents the total number of elements from which the sample is chosen .

r

• is an optional integer value that represents the number of chosen elements. If r is omitted, the function returns the factorial of n .

• Restriction: r ‰ n

Details

The mathematical representation of the PERM function is given by the following equation:

with n ‰ 0, r ‰ 0, and n ‰ r .

If the expression cannot be computed, a missing value is returned.

Examples

SAS Statements	Results
x=perm(5,1);	5
x=perm(5);	120
x=perm(5,2)	20

See Also

Functions:

• 'COMB Function' on page 444

• 'FACT Function' on page 517