LPERM Function

Computes the logarithm of the PERM function, which is the logarithm of the number of permutations of n objects, with the option of including r number of elements.

Category:

Combinatorial

Syntax

LPERM(n<,r> )

Required Argument

n

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

Optional Argument

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 LPERM function computes the logarithm of the PERM function.

Example

The following SAS statements produce these results.

SAS Statement	Result
x=lperm(5000,500); put x;	4232.7715946
y=lperm(100,10); put y;	45.586735935