de.unihalle.informatik.MiToBo.math

Class MathX

java.lang.Object

de.unihalle.informatik.MiToBo.math.MathX

public class MathX
extends Object

Math class with functions that are not provided by Java's Math class.

Author:

Oliver Gress

Constructor Summary

Constructors

Constructor and Description
MathX()

Method Summary

Modifier and Type	Method and Description
static double	binomial(int n, int k) Binomial coefficient of n over k
static int	factorial(int n) Calculates the factorial of the given natural number.
static double	logSumP(double logP1, double logP2) Natural logarithm of the sum of two values P1 and P2 when only their natural logarithms log(P1) and log(P2) are given.

Methods inherited from class java.lang.Object

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

Constructor Detail

MathX

public MathX()

Method Detail

logSumP

public static double logSumP(double logP1,
                             double logP2)

Natural logarithm of the sum of two values P1 and P2 when only their natural logarithms log(P1) and log(P2) are given.

Parameters:

logP1 - natural logarithm of P1: log(P1)

logP2 - natural logarithm of P2: log(P2)

Returns:

log( P1 + P2 )

factorial

public static int factorial(int n)

Calculates the factorial of the given natural number.

\begin{equation*} n! = \prod_{i=1}^n i \end{equation*}

Parameters:

n - Number to calculate the factorial for, must be positive.

Returns:

Factorial of n.

binomial

public static double binomial(int n,
                              int k)

Binomial coefficient of n over k

Parameters:

n -

k -

Returns: