# 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.

## Syntax

### 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.

## Details

The LPERM function computes
the logarithm of the PERM function.

## Example

The following SAS statements
produce these results.