broadwick.math

Class Factorial

java.lang.Object

broadwick.math.Factorial

public final class Factorial
extends Object

A recursive program to calculate the factorial of a number. n! = n * (n-1) * (n-2) * ... * 1

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Factorial() Hiding constructor for utility class.

Method Summary

Modifier and Type	Method and Description
static BigDecimal	factorial(int n) Calculate the factorial of n.
static double	lnFactorial(int n) Returns the value of the natural logarithm of factorial n.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Factorial

private Factorial()

Hiding constructor for utility class.

Method Detail

factorial

public static BigDecimal factorial(int n)

Calculate the factorial of n.

Parameters:

n - the number to calculate the factorial of.

Returns:

the factorial of n.

lnFactorial

public static double lnFactorial(int n)

Returns the value of the natural logarithm of factorial n. Gives 16 decimals of precision (relative error < 0.5×10^-15).

Parameters:

n - the integer for which the log-factorial has to be computed

Returns:

the natural logarithm of n factorial